Rambda
Rambda
is smaller and faster alternative to the popular functional programming library Ramda. - Documentation
❯ Example use
import { compose, map, filter } from 'rambda'
const result = compose(
map(x => x * 2),
filter(x => x > 2)
)([1, 2, 3, 4])
You can test this example in Rambda's REPL
❯ Rambda's advantages
Typescript included
Typescript definitions are included in the library, in comparison to Ramda, where you need to additionally install @types/ramda
.
Still, you need to be aware that functional programming features in Typescript
are in development, which means that using R.compose/R.pipe can be problematic.
Important - Rambda version 7.1.0
(or higher) requires Typescript version 4.3.3
(or higher).
Immutable TS definitions
You can use immutable version of Rambda definitions, which is linted with ESLint functional/prefer-readonly-type
plugin.
import {add} from 'rambda/immutable'
Deno support
While Ramda
is available for Deno
users, Rambda
provides you with included TS definitions:
import * as R from "https://x.nest.land/rambda@7.1.0/mod.ts";
import * as Ramda from "https://x.nest.land/ramda@0.28.0/mod.ts";
R.add(1)('foo') // => will trigger warning in VSCode
Ramda.add(1)('foo') // => will not trigger warning in VSCode
Smaller size
The size of a library affects not only the build bundle size but also the dev bundle size and build time. This is important advantage, expecially for big projects.
Tree-shaking
Currently Rambda is more tree-shakable than Ramda - proven in the following repo.
The repo holds two Angular9
applications: one with small example code of Ramda and the other - same code but with Rambda as import library.
The test shows that Rambda bundle size is 2 MB less than its Ramda counterpart.
There is also Webpack/Rollup/Parcel/Esbuild tree-shaking example including several libraries including Ramda
, Rambda
and Rambdax
.
actually tree-shaking is the initial reason for creation of Rambda
Dot notation for R.path
, R.paths
, R.assocPath
and R.lensPath
Standard usage of R.path
is R.path(['a', 'b'], {a: {b: 1} })
.
In Rambda you have the choice to use dot notation(which is arguably more readable):
R.path('a.b', {a: {b: 1} })
Comma notation for R.pick
and R.omit
Similar to dot notation, but the separator is comma(,
) instead of dot(.
).
R.pick('a,b', {a: 1 , b: 2, c: 3} })
// No space allowed between properties
Speed
Rambda is generally more performant than Ramda
as the benchmarks can prove that.
Deno
Support
As the library is smaller than Ramda, issues are much faster resolved.
Closing the issue is usually accompanied by publishing a new patch version of Rambda
to NPM.
❯ Missing Ramda methods
Click to see the full list of 80 Ramda methods not implemented in Rambda
- __
- addIndex
- ap
- aperture
- applyTo
- ascend
- binary
- call
- collectBy
- comparator
- composeWith
- construct
- constructN
- descend
- differenceWith
- dissocPath
- empty
- eqBy
- forEachObjIndexed
- gt
- gte
- hasIn
- innerJoin
- insert
- insertAll
- into
- invert
- invertObj
- invoker
- keysIn
- lift
- liftN
- lt
- lte
- mapAccum
- mapAccumRight
- memoizeWith
- mergeDeepLeft
- mergeDeepWith
- mergeDeepWithKey
- mergeWithKey
- modify
- modifyPath
- nAry
- nthArg
- o
- otherwise
- pair
- partialRight
- pathSatisfies
- pickBy
- pipeWith
- project
- promap
- reduceBy
- reduceRight
- reduceWhile
- reduced
- remove
- scan
- sequence
- sortWith
- splitWhenever
- symmetricDifferenceWith
- andThen
- toPairsIn
- transduce
- traverse
- unary
- uncurryN
- unfold
- unionWith
- uniqBy
- unnest
- until
- useWith
- valuesIn
- xprod
- thunkify
- default
❯ Install
https://unpkg.com/rambda@CURRENT_VERSION/dist/rambda.umd.js
import {compose, add} from 'https://raw.githubusercontent.com/selfrefactor/rambda/master/dist/rambda.esm.js'
Differences between Rambda and Ramda
-
Rambda's type detects async functions and unresolved Promises
. The returned values are 'Async'
and 'Promise'
.
-
Rambda's type handles NaN input, in which case it returns NaN
.
-
Rambda's forEach can iterate over objects not only arrays.
-
Rambda's map, filter, partition when they iterate over objects, they pass property and input object as predicate's argument.
-
Rambda's filter returns empty array with bad input(null
or undefined
), while Ramda throws.
-
Ramda's clamp work with strings, while Rambda's method work only with numbers.
-
Ramda's indexOf/lastIndexOf work with strings and lists, while Rambda's method work only with lists as iterable input.
-
Error handling, when wrong inputs are provided, may not be the same. This difference will be better documented once all brute force tests are completed.
-
Typescript definitions between rambda
and @types/ramda
may vary.
If you need more Ramda methods in Rambda, you may either submit a PR
or check the extended version of Rambda - Rambdax. In case of the former, you may want to consult with Rambda contribution guidelines.
❯ Benchmarks
Click to expand all benchmark results
There are methods which are benchmarked only with Ramda
and Rambda
(i.e. no Lodash
).
Note that some of these methods, are called with and without curring. This is done in order to give more detailed performance feedback.
The benchmarks results are produced from latest versions of Rambda, Lodash(4.17.21) and Ramda(0.28.0).
method | Rambda | Ramda | Lodash |
---|
add | 🚀 Fastest | 21.52% slower | 82.15% slower |
adjust | 8.48% slower | 🚀 Fastest | 🔳 |
all | 🚀 Fastest | 3.79% slower | 🔳 |
allPass | 🚀 Fastest | 87.3% slower | 🔳 |
allPass | 🚀 Fastest | 98.56% slower | 🔳 |
and | 🚀 Fastest | 89.09% slower | 🔳 |
any | 🚀 Fastest | 92.87% slower | 45.82% slower |
anyPass | 🚀 Fastest | 98.25% slower | 🔳 |
append | 🚀 Fastest | 2.07% slower | 🔳 |
applySpec | 🚀 Fastest | 80.43% slower | 🔳 |
assoc | 72.32% slower | 60.08% slower | 🚀 Fastest |
clone | 🚀 Fastest | 91.86% slower | 86.48% slower |
compose | 1.91% slower | 21.6% slower | 🚀 Fastest |
converge | 78.63% slower | 🚀 Fastest | 🔳 |
curry | 🚀 Fastest | 28.86% slower | 🔳 |
curryN | 🚀 Fastest | 41.05% slower | 🔳 |
defaultTo | 🚀 Fastest | 48.91% slower | 🔳 |
drop | 🚀 Fastest | 82.35% slower | 🔳 |
dropLast | 🚀 Fastest | 86.74% slower | 🔳 |
equals | 58.37% slower | 96.73% slower | 🚀 Fastest |
filter | 6.7% slower | 72.03% slower | 🚀 Fastest |
find | 🚀 Fastest | 85.14% slower | 42.65% slower |
findIndex | 🚀 Fastest | 86.48% slower | 72.27% slower |
flatten | 🚀 Fastest | 95.26% slower | 10.27% slower |
ifElse | 🚀 Fastest | 58.56% slower | 🔳 |
includes | 🚀 Fastest | 84.68% slower | 🔳 |
indexOf | 🚀 Fastest | 83.07% slower | 🔳 |
indexOf | 🚀 Fastest | 82.2% slower | 🔳 |
init | 🚀 Fastest | 92.24% slower | 13.3% slower |
is | 🚀 Fastest | 57.69% slower | 🔳 |
isEmpty | 🚀 Fastest | 97.14% slower | 54.99% slower |
last | 🚀 Fastest | 93.43% slower | 5.28% slower |
lastIndexOf | 🚀 Fastest | 85.19% slower | 🔳 |
map | 🚀 Fastest | 86.6% slower | 11.73% slower |
match | 🚀 Fastest | 44.83% slower | 🔳 |
merge | 🚀 Fastest | 12.21% slower | 55.76% slower |
none | 🚀 Fastest | 96.48% slower | 🔳 |
objOf | 🚀 Fastest | 38.05% slower | 🔳 |
omit | 🚀 Fastest | 69.95% slower | 97.34% slower |
over | 🚀 Fastest | 56.23% slower | 🔳 |
path | 37.81% slower | 77.81% slower | 🚀 Fastest |
pick | 🚀 Fastest | 19.07% slower | 80.2% slower |
pipe | 0.41% slower | 🚀 Fastest | 🔳 |
prop | 🚀 Fastest | 87.95% slower | 🔳 |
propEq | 🚀 Fastest | 91.92% slower | 🔳 |
range | 🚀 Fastest | 61.8% slower | 57.44% slower |
reduce | 60.48% slower | 77.1% slower | 🚀 Fastest |
repeat | 48.57% slower | 68.98% slower | 🚀 Fastest |
replace | 33.45% slower | 33.99% slower | 🚀 Fastest |
set | 🚀 Fastest | 50.35% slower | 🔳 |
sort | 🚀 Fastest | 40.23% slower | 🔳 |
sortBy | 🚀 Fastest | 25.29% slower | 56.88% slower |
split | 🚀 Fastest | 55.37% slower | 17.64% slower |
splitEvery | 🚀 Fastest | 71.98% slower | 🔳 |
take | 🚀 Fastest | 91.96% slower | 4.72% slower |
takeLast | 🚀 Fastest | 93.39% slower | 19.22% slower |
test | 🚀 Fastest | 82.34% slower | 🔳 |
type | 🚀 Fastest | 48.6% slower | 🔳 |
uniq | 🚀 Fastest | 86.73% slower | 🔳 |
uniqWith | 13.67% slower | 🚀 Fastest | 🔳 |
uniqWith | 14.23% slower | 🚀 Fastest | 🔳 |
update | 🚀 Fastest | 52.35% slower | 🔳 |
view | 🚀 Fastest | 76.15% slower | 🔳 |
❯ Used by
API
add
add(a: number, b: number): number
It adds a
and b
.
All Typescript definitions
add(a: number, b: number): number;
add(a: number): (b: number) => number;
R.add source
export function add(a, b){
if (arguments.length === 1) return _b => add(a, _b)
return Number(a) + Number(b)
}
Tests
import { add as addRamda } from 'ramda'
import { compareCombinations } from './_internals/testUtils.js'
import { add } from './add.js'
test('with number', () => {
expect(add(2, 3)).toEqual(5)
expect(add(7)(10)).toEqual(17)
})
test('string is bad input', () => {
expect(add('foo', 'bar')).toBeNaN()
})
test('ramda specs', () => {
expect(add('1', '2')).toEqual(3)
expect(add(1, '2')).toEqual(3)
expect(add(true, false)).toEqual(1)
expect(add(null, null)).toEqual(0)
expect(add(undefined, undefined)).toEqual(NaN)
expect(add(new Date(1), new Date(2))).toEqual(3)
})
const possibleInputs = [
/foo/,
'foo',
true,
3,
NaN,
4,
[],
Promise.resolve(1),
]
describe('brute force', () => {
compareCombinations({
fn : add,
fnRamda : addRamda,
firstInput : possibleInputs,
secondInput : possibleInputs,
callback : errorsCounters => {
expect(errorsCounters).toMatchInlineSnapshot(`
Object {
"ERRORS_MESSAGE_MISMATCH": 0,
"ERRORS_TYPE_MISMATCH": 0,
"RESULTS_MISMATCH": 0,
"SHOULD_NOT_THROW": 0,
"SHOULD_THROW": 0,
"TOTAL_TESTS": 64,
}
`)
},
})
})
Typescript test
import {add} from 'rambda'
describe('R.add', () => {
it('happy', () => {
const result = add(4, 1)
result
})
it('curried', () => {
const result = add(4)(1)
result
})
})
Rambda is fastest. Ramda is 21.52% slower and Lodash is 82.15% slower
const R = require('../../dist/rambda.js')
const add = [
{
label : 'Rambda',
fn : () => {
R.add(1, 1)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.add(1, 1)
},
},
{
label : 'Lodash',
fn : () => {
_.add(1, 1)
},
},
]
adjust
adjust<T>(index: number, replaceFn: (x: T) => T, list: T[]): T[]
It replaces index
in array list
with the result of replaceFn(list[i])
.
All Typescript definitions
adjust<T>(index: number, replaceFn: (x: T) => T, list: T[]): T[];
adjust<T>(index: number, replaceFn: (x: T) => T): (list: T[]) => T[];
R.adjust source
import { cloneList } from './_internals/cloneList.js'
import { curry } from './curry.js'
function adjustFn(
index, replaceFn, list
){
const actualIndex = index < 0 ? list.length + index : index
if (index >= list.length || actualIndex < 0) return list
const clone = cloneList(list)
clone[ actualIndex ] = replaceFn(clone[ actualIndex ])
return clone
}
export const adjust = curry(adjustFn)
Tests
import { add } from './add.js'
import { adjust } from './adjust.js'
import { pipe } from './pipe.js'
const list = [ 0, 1, 2 ]
const expected = [ 0, 11, 2 ]
test('happy', () => {})
test('happy', () => {
expect(adjust(
1, add(10), list
)).toEqual(expected)
})
test('with curring type 1 1 1', () => {
expect(adjust(1)(add(10))(list)).toEqual(expected)
})
test('with curring type 1 2', () => {
expect(adjust(1)(add(10), list)).toEqual(expected)
})
test('with curring type 2 1', () => {
expect(adjust(1, add(10))(list)).toEqual(expected)
})
test('with negative index', () => {
expect(adjust(
-2, add(10), list
)).toEqual(expected)
})
test('when index is out of bounds', () => {
const list = [ 0, 1, 2, 3 ]
expect(adjust(
4, add(1), list
)).toEqual(list)
expect(adjust(
-5, add(1), list
)).toEqual(list)
})
Rambda is slower than Ramda with 8.48%
const R = require('../../dist/rambda.js')
const list = [ 0, 1, 2 ]
const fn = x => x + 1
const index = 1
const adjust = [
{
label : 'Rambda',
fn : () => {
R.adjust(
index, fn, list
)
R.adjust(index, fn)(list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.adjust(
index, fn, list
)
Ramda.adjust(index, fn)(list)
},
},
]
all
all<T>(predicate: (x: T) => boolean, list: T[]): boolean
It returns true
, if all members of array list
returns true
, when applied as argument to predicate
function.
All Typescript definitions
all<T>(predicate: (x: T) => boolean, list: T[]): boolean;
all<T>(predicate: (x: T) => boolean): (list: T[]) => boolean;
R.all source
export function all(predicate, list){
if (arguments.length === 1) return _list => all(predicate, _list)
for (let i = 0; i < list.length; i++){
if (!predicate(list[ i ])) return false
}
return true
}
Tests
import { all } from './all.js'
const list = [ 0, 1, 2, 3, 4 ]
test('when true', () => {
const fn = x => x > -1
expect(all(fn)(list)).toBeTrue()
})
test('when false', () => {
const fn = x => x > 2
expect(all(fn, list)).toBeFalse()
})
Typescript test
import {all} from 'rambda'
describe('all', () => {
it('happy', () => {
const result = all(
x => {
x
return x > 0
},
[1, 2, 3]
)
result
})
it('curried needs a type', () => {
const result = all<number>(x => {
x
return x > 0
})([1, 2, 3])
result
})
})
Rambda is faster than Ramda with 3.79%
const R = require('../../dist/rambda.js')
const {
uniqListOfObjects,
uniqListOfStrings,
rangeOfNumbers,
uniqListOfLists,
} = require('./_utils.js')
const limit = 100
const modes = [
[ uniqListOfObjects(limit), x => Object.keys(x).length > 2 ],
[ uniqListOfStrings(limit), x => x.length > 0 ],
[ uniqListOfLists(limit), x => x.length > 0 ],
[ rangeOfNumbers(limit), x => x > -1 ],
]
const applyBenchmark = (fn, input) => fn(input[ 1 ], input[ 0 ])
const tests = [
{
label : 'Rambda',
fn : R.all,
},
{
label : 'Ramda',
fn : Ramda.all,
},
]
tests,
applyBenchmark,
modes,
}
allPass
allPass<T>(predicates: ((x: T) => boolean)[]): (input: T) => boolean
It returns true
, if all functions of predicates
return true
, when input
is their argument.
All Typescript definitions
allPass<T>(predicates: ((x: T) => boolean)[]): (input: T) => boolean;
R.allPass source
export function allPass(predicates){
return (...input) => {
let counter = 0
while (counter < predicates.length){
if (!predicates[ counter ](...input)){
return false
}
counter++
}
return true
}
}
Tests
import { allPass } from './allPass.js'
test('happy', () => {
const rules = [ x => typeof x === 'number', x => x > 10, x => x * 7 < 100 ]
expect(allPass(rules)(11)).toBeTrue()
expect(allPass(rules)(undefined)).toBeFalse()
})
test('when returns true', () => {
const conditionArr = [ val => val.a === 1, val => val.b === 2 ]
expect(allPass(conditionArr)({
a : 1,
b : 2,
})).toBeTrue()
})
test('when returns false', () => {
const conditionArr = [ val => val.a === 1, val => val.b === 3 ]
expect(allPass(conditionArr)({
a : 1,
b : 2,
})).toBeFalse()
})
test('works with multiple inputs', () => {
const fn = function (
w, x, y, z
){
return w + x === y + z
}
expect(allPass([ fn ])(
3, 3, 3, 3
)).toBeTrue()
})
Typescript test
import {allPass} from 'rambda'
describe('allPass', () => {
it('happy', () => {
const x = allPass<number>([
y => {
y
return typeof y === 'number'
},
y => {
return y > 0
},
])(11)
x
})
})
Rambda is faster than Ramda with 87.3%
const R = require('../../dist/rambda.js')
const { random } = require('rambdax')
const limit = 100
const min = 10
const max = 1200
function createListOfFunctions(fn, fnLimit){
return Array(fnLimit)
.fill(null)
.map(() => fn())
}
const modes = [
[
{ foo : 1500 },
createListOfFunctions(() => x => Number(x.foo) > random(min, max),
limit),
],
[
'1500',
createListOfFunctions(() => x => Number(x) > random(min, max), limit),
],
[
[ 1, 2, 1500 ],
createListOfFunctions(() => x => x[ 2 ] > random(min, max), limit),
],
[ 1500, createListOfFunctions(() => x => x > random(min, max), limit) ],
]
const applyBenchmark = (fn, input) => fn(input[ 1 ])(input[ 0 ])
const tests = [
{
label : 'Rambda',
fn : R.allPass,
},
{
label : 'Ramda',
fn : Ramda.allPass,
},
]
tests,
modes,
applyBenchmark,
}
always
always<T>(x: T): (...args: unknown[]) => T
It returns function that always returns x
.
All Typescript definitions
always<T>(x: T): (...args: unknown[]) => T;
R.always source
export function always(x){
return _ => x
}
Tests
import { always } from './always.js'
import { applySpec } from './applySpec.js'
test('happy', () => {
const fn = always(7)
expect(fn()).toBe(7)
expect(fn()).toBe(7)
})
test('compatibility with applySpec', () => {
const spec = applySpec({ x : always('foo') })
expect(spec({})).toEqual({ x : 'foo' })
})
Typescript test
import {always} from 'rambda'
describe('R.always', () => {
it('happy', () => {
const fn = always('foo')
fn
const result = fn()
result
})
})
and
Logical AND
any
any<T>(predicate: (x: T) => boolean, list: T[]): boolean
It returns true
, if at least one member of list
returns true, when passed to a predicate
function.
All Typescript definitions
any<T>(predicate: (x: T) => boolean, list: T[]): boolean;
any<T>(predicate: (x: T) => boolean): (list: T[]) => boolean;
R.any source
export function any(predicate, list){
if (arguments.length === 1) return _list => any(predicate, _list)
let counter = 0
while (counter < list.length){
if (predicate(list[ counter ], counter)){
return true
}
counter++
}
return false
}
Tests
import { any } from './any.js'
const list = [ 1, 2, 3 ]
test('happy', () => {
expect(any(x => x < 0, list)).toBeFalse()
})
test('with curry', () => {
expect(any(x => x > 2)(list)).toBeTrue()
})
Typescript test
import {any} from 'rambda'
describe('R.any', () => {
it('happy', () => {
const result = any(
x => {
x
return x > 2
},
[1, 2, 3]
)
result
})
it('when curried needs a type', () => {
const result = any<number>(x => {
x
return x > 2
})([1, 2, 3])
result
})
})
Rambda is fastest. Ramda is 92.87% slower and Lodash is 45.82% slower
const R = require('../../dist/rambda.js')
const input = [ 1, 2, 3, 4 ]
const fn = val => val > 2
const any = [
{
label : 'Rambda',
fn : () => {
R.any(fn, input)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.any(fn, input)
},
},
{
label : 'Lodash.some',
fn : () => {
_.some(input, fn)
},
},
]
anyPass
anyPass<T>(predicates: SafePred<T>[]): SafePred<T>
It accepts list of predicates
and returns a function. This function with its input
will return true
, if any of predicates
returns true
for this input
.
All Typescript definitions
anyPass<T>(predicates: SafePred<T>[]): SafePred<T>;
R.anyPass source
export function anyPass(predicates){
return (...input) => {
let counter = 0
while (counter < predicates.length){
if (predicates[ counter ](...input)){
return true
}
counter++
}
return false
}
}
Tests
import {anyPass} from './anyPass.js'
test('happy', () => {
const rules = [x => typeof x === 'string', x => x > 10]
const predicate = anyPass(rules)
expect(predicate('foo')).toBeTrue()
expect(predicate(6)).toBeFalse()
})
test('happy', () => {
const rules = [x => typeof x === 'string', x => x > 10]
expect(anyPass(rules)(11)).toBeTrue()
expect(anyPass(rules)(undefined)).toBeFalse()
})
const obj = {
a: 1,
b: 2,
}
test('when returns true', () => {
const conditionArr = [val => val.a === 1, val => val.a === 2]
expect(anyPass(conditionArr)(obj)).toBeTrue()
})
test('when returns false + curry', () => {
const conditionArr = [val => val.a === 2, val => val.b === 3]
expect(anyPass(conditionArr)(obj)).toBeFalse()
})
test('with empty predicates list', () => {
expect(anyPass([])(3)).toBeFalse()
})
test('works with multiple inputs', () => {
const fn = function (w, x, y, z) {
console.log(w, x, y, z)
return w + x === y + z
}
expect(anyPass([fn])(3, 3, 3, 3)).toBeTrue()
})
Typescript test
import {anyPass} from 'rambda'
describe('anyPass', () => {
it('happy', () => {
const x = anyPass<number>([
y => {
y
return typeof y === 'number'
},
y => {
return y > 0
},
])(11)
x
})
})
Rambda is faster than Ramda with 98.25%
const R = require('../../dist/rambda.js')
const rules = [ x => typeof x === 'boolean', x => x > 20, x => x * 7 < 100 ]
const anyPass = [
{
label : 'Rambda',
fn : () => {
R.anyPass(rules)(11)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.anyPass(rules)(11)
},
},
]
append
append<T>(x: T, list: T[]): T[]
It adds element x
at the end of list
.
All Typescript definitions
append<T>(x: T, list: T[]): T[];
append<T>(x: T): <T>(list: T[]) => T[];
R.append source
import { cloneList } from './_internals/cloneList.js'
export function append(x, input){
if (arguments.length === 1) return _input => append(x, _input)
if (typeof input === 'string') return input.split('').concat(x)
const clone = cloneList(input)
clone.push(x)
return clone
}
Tests
import { append } from './append.js'
test('happy', () => {
expect(append('tests', [ 'write', 'more' ])).toEqual([
'write',
'more',
'tests',
])
})
test('append to empty array', () => {
expect(append('tests')([])).toEqual([ 'tests' ])
})
test('with strings', () => {
expect(append('o', 'fo')).toEqual([ 'f', 'o', 'o' ])
})
Typescript test
import {append} from 'rambda'
const list = [1, 2, 3]
describe('R.append', () => {
it('happy', () => {
const result = append(4, list)
result
})
it('curried', () => {
const result = append(4)(list)
result
})
})
Rambda is faster than Ramda with 2.07%
const R = require('../../dist/rambda.js')
const append = [
{
label : 'Rambda',
fn : () => {
R.append(0)([ 1, 2, 3, 4 ])
R.append('bar')('foo')
},
},
{
label : 'Ramda',
fn : () => {
Ramda.append(0)([ 1, 2, 3, 4 ])
Ramda.append('bar')('foo')
},
},
]
apply
apply<T = any>(fn: (...args: any[]) => T, args: any[]): T
It applies function fn
to the list of arguments.
This is useful for creating a fixed-arity function from a variadic function. fn
should be a bound function if context is significant.
All Typescript definitions
apply<T = any>(fn: (...args: any[]) => T, args: any[]): T;
apply<T = any>(fn: (...args: any[]) => T): (args: any[]) => T;
R.apply source
export function apply(fn, args){
if (arguments.length === 1){
return _args => apply(fn, _args)
}
return fn.apply(this, args)
}
Tests
import {apply} from './apply.js'
import {bind} from './bind.js'
import {identity} from './identity.js'
test('happy', () => {
expect(apply(identity, [1, 2, 3])).toEqual(1)
})
test('applies function to argument list', () => {
expect(apply(Math.max, [1, 2, 3, -99, 42, 6, 7])).toEqual(42)
})
test('provides no way to specify context', () => {
const obj = {
method: function () {
return this === obj
},
}
expect(apply(obj.method, [])).toBeFalse()
expect(apply(bind(obj.method, obj), [])).toBeTrue()
})
Typescript test
import {apply, identity} from 'rambda'
describe('R.apply', () => {
it('happy', () => {
const result = apply<number>(identity, [1, 2, 3])
result
})
it('curried', () => {
const fn = apply<number>(identity)
const result = fn([1, 2, 3])
result
})
})
applySpec
applySpec<Spec extends Record<string, (...args: any[]) => any>>(
spec: Spec
): (
...args: Parameters<ValueOfRecord<Spec>>
) => { [Key in keyof Spec]: ReturnType<Spec[Key]> }
All Typescript definitions
applySpec<Spec extends Record<string, (...args: any[]) => any>>(
spec: Spec
): (
...args: Parameters<ValueOfRecord<Spec>>
) => { [Key in keyof Spec]: ReturnType<Spec[Key]> };
applySpec<T>(spec: any): (...args: any[]) => T;
R.applySpec source
import { _isArray } from './_internals/_isArray.js'
export function __findHighestArity(spec, max = 0){
for (const key in spec){
if (spec.hasOwnProperty(key) === false || key === 'constructor') continue
if (typeof spec[ key ] === 'object'){
max = Math.max(max, __findHighestArity(spec[ key ]))
}
if (typeof spec[ key ] === 'function'){
max = Math.max(max, spec[ key ].length)
}
}
return max
}
function __filterUndefined(){
const defined = []
let i = 0
const l = arguments.length
while (i < l){
if (typeof arguments[ i ] === 'undefined') break
defined[ i ] = arguments[ i ]
i++
}
return defined
}
function __applySpecWithArity(
spec, arity, cache
){
const remaining = arity - cache.length
if (remaining === 1)
return x =>
__applySpecWithArity(
spec, arity, __filterUndefined(...cache, x)
)
if (remaining === 2)
return (x, y) =>
__applySpecWithArity(
spec, arity, __filterUndefined(
...cache, x, y
)
)
if (remaining === 3)
return (
x, y, z
) =>
__applySpecWithArity(
spec, arity, __filterUndefined(
...cache, x, y, z
)
)
if (remaining === 4)
return (
x, y, z, a
) =>
__applySpecWithArity(
spec,
arity,
__filterUndefined(
...cache, x, y, z, a
)
)
if (remaining > 4)
return (...args) =>
__applySpecWithArity(
spec, arity, __filterUndefined(...cache, ...args)
)
if (_isArray(spec)){
const ret = []
let i = 0
const l = spec.length
for (; i < l; i++){
if (typeof spec[ i ] === 'object' || _isArray(spec[ i ])){
ret[ i ] = __applySpecWithArity(
spec[ i ], arity, cache
)
}
if (typeof spec[ i ] === 'function'){
ret[ i ] = spec[ i ](...cache)
}
}
return ret
}
const ret = {}
for (const key in spec){
if (spec.hasOwnProperty(key) === false || key === 'constructor') continue
if (typeof spec[ key ] === 'object'){
ret[ key ] = __applySpecWithArity(
spec[ key ], arity, cache
)
continue
}
if (typeof spec[ key ] === 'function'){
ret[ key ] = spec[ key ](...cache)
}
}
return ret
}
export function applySpec(spec, ...args){
const arity = __findHighestArity(spec)
if (arity === 0){
return () => ({})
}
const toReturn = __applySpecWithArity(
spec, arity, args
)
return toReturn
}
Tests
import { applySpec as applySpecRamda, nAry } from 'ramda'
import { add, always, compose, dec, inc, map, path, prop, T } from '../rambda.js'
import { applySpec } from './applySpec.js'
test('different than Ramda when bad spec', () => {
const result = applySpec({ sum : { a : 1 } })(1, 2)
const ramdaResult = applySpecRamda({ sum : { a : 1 } })(1, 2)
expect(result).toEqual({})
expect(ramdaResult).toEqual({ sum : { a : {} } })
})
test('works with empty spec', () => {
expect(applySpec({})()).toEqual({})
expect(applySpec([])(1, 2)).toEqual({})
expect(applySpec(null)(1, 2)).toEqual({})
})
test('works with unary functions', () => {
const result = applySpec({
v : inc,
u : dec,
})(1)
const expected = {
v : 2,
u : 0,
}
expect(result).toEqual(expected)
})
test('works with binary functions', () => {
const result = applySpec({ sum : add })(1, 2)
expect(result).toEqual({ sum : 3 })
})
test('works with nested specs', () => {
const result = applySpec({
unnested : always(0),
nested : { sum : add },
})(1, 2)
const expected = {
unnested : 0,
nested : { sum : 3 },
}
expect(result).toEqual(expected)
})
test('works with arrays of nested specs', () => {
const result = applySpec({
unnested : always(0),
nested : [ { sum : add } ],
})(1, 2)
expect(result).toEqual({
unnested : 0,
nested : [ { sum : 3 } ],
})
})
test('works with arrays of spec objects', () => {
const result = applySpec([ { sum : add } ])(1, 2)
expect(result).toEqual([ { sum : 3 } ])
})
test('works with arrays of functions', () => {
const result = applySpec([ map(prop('a')), map(prop('b')) ])([
{
a : 'a1',
b : 'b1',
},
{
a : 'a2',
b : 'b2',
},
])
const expected = [
[ 'a1', 'a2' ],
[ 'b1', 'b2' ],
]
expect(result).toEqual(expected)
})
test('works with a spec defining a map key', () => {
expect(applySpec({ map : prop('a') })({ a : 1 })).toEqual({ map : 1 })
})
test('cannot retains the highest arity', () => {
const f = applySpec({
f1 : nAry(2, T),
f2 : nAry(5, T),
})
const fRamda = applySpecRamda({
f1 : nAry(2, T),
f2 : nAry(5, T),
})
expect(f.length).toBe(0)
expect(fRamda.length).toBe(5)
})
test('returns a curried function', () => {
expect(applySpec({ sum : add })(1)(2)).toEqual({ sum : 3 })
})
test('arity', () => {
const spec = {
one : x1 => x1,
two : (x1, x2) => x1 + x2,
three : (
x1, x2, x3
) => x1 + x2 + x3,
}
expect(applySpec(
spec, 1, 2, 3
)).toEqual({
one : 1,
two : 3,
three : 6,
})
})
test('arity over 5 arguments', () => {
const spec = {
one : x1 => x1,
two : (x1, x2) => x1 + x2,
three : (
x1, x2, x3
) => x1 + x2 + x3,
four : (
x1, x2, x3, x4
) => x1 + x2 + x3 + x4,
five : (
x1, x2, x3, x4, x5
) => x1 + x2 + x3 + x4 + x5,
}
expect(applySpec(
spec, 1, 2, 3, 4, 5
)).toEqual({
one : 1,
two : 3,
three : 6,
four : 10,
five : 15,
})
})
test('curried', () => {
const spec = {
one : x1 => x1,
two : (x1, x2) => x1 + x2,
three : (
x1, x2, x3
) => x1 + x2 + x3,
}
expect(applySpec(spec)(1)(2)(3)).toEqual({
one : 1,
two : 3,
three : 6,
})
})
test('curried over 5 arguments', () => {
const spec = {
one : x1 => x1,
two : (x1, x2) => x1 + x2,
three : (
x1, x2, x3
) => x1 + x2 + x3,
four : (
x1, x2, x3, x4
) => x1 + x2 + x3 + x4,
five : (
x1, x2, x3, x4, x5
) => x1 + x2 + x3 + x4 + x5,
}
expect(applySpec(spec)(1)(2)(3)(4)(5)).toEqual({
one : 1,
two : 3,
three : 6,
four : 10,
five : 15,
})
})
test('undefined property', () => {
const spec = { prop : path([ 'property', 'doesnt', 'exist' ]) }
expect(applySpec(spec, {})).toEqual({ prop : undefined })
})
test('restructure json object', () => {
const spec = {
id : path('user.id'),
name : path('user.firstname'),
profile : path('user.profile'),
doesntExist : path('user.profile.doesntExist'),
info : { views : compose(inc, prop('views')) },
type : always('playa'),
}
const data = {
user : {
id : 1337,
firstname : 'john',
lastname : 'shaft',
profile : 'shaft69',
},
views : 42,
}
expect(applySpec(spec, data)).toEqual({
id : 1337,
name : 'john',
profile : 'shaft69',
doesntExist : undefined,
info : { views : 43 },
type : 'playa',
})
})
Typescript test
import {multiply, applySpec, inc, dec, add} from 'rambda'
describe('applySpec', () => {
it('ramda 1', () => {
const result = applySpec({
v: inc,
u: dec,
})(1)
result
})
it('ramda 1', () => {
interface Output {
sum: number
multiplied: number
}
const result = applySpec<Output>({
sum: add,
multiplied: multiply,
})(1, 2)
result
})
})
Rambda is faster than Ramda with 80.43%
const R = require('../../dist/rambda.js')
const curryN = [
{
label : 'Rambda',
fn : () => {
const data = {
a : {
b : { c : 1 },
d : 2,
},
}
const spec = {
c : R.path([ 'a', 'b', 'c' ]),
d : R.path([ 'a', 'd' ]),
}
R.applySpec(spec, data)
},
},
{
label : 'Ramda',
fn : () => {
const data = {
a : {
b : { c : 1 },
d : 2,
},
}
const spec = {
c : Ramda.path([ 'a', 'b', 'c' ]),
d : Ramda.path([ 'a', 'd' ]),
}
Ramda.applySpec(spec, data)
},
},
]
assoc
assoc<T, U, K extends string>(prop: K, val: T, obj: U): Record<K, T> & Omit<U, K>
It makes a shallow clone of obj
with setting or overriding the property prop
with newValue
.
All Typescript definitions
assoc<T, U, K extends string>(prop: K, val: T, obj: U): Record<K, T> & Omit<U, K>;
assoc<T, K extends string>(prop: K, val: T): <U>(obj: U) => Record<K, T> & Omit<U, K>;
assoc<K extends string>(prop: K): AssocPartialOne<K>;
R.assoc source
import { curry } from './curry.js'
function assocFn(
prop, newValue, obj
){
return Object.assign(
{}, obj, { [ prop ] : newValue }
)
}
export const assoc = curry(assocFn)
Tests
import { assoc } from './assoc.js'
test('adds a key to an empty object', () => {
expect(assoc(
'a', 1, {}
)).toEqual({ a : 1 })
})
test('adds a key to a non-empty object', () => {
expect(assoc(
'b', 2, { a : 1 }
)).toEqual({
a : 1,
b : 2,
})
})
test('adds a key to a non-empty object - curry case 1', () => {
expect(assoc('b', 2)({ a : 1 })).toEqual({
a : 1,
b : 2,
})
})
test('adds a key to a non-empty object - curry case 2', () => {
expect(assoc('b')(2, { a : 1 })).toEqual({
a : 1,
b : 2,
})
})
test('adds a key to a non-empty object - curry case 3', () => {
const result = assoc('b')(2)({ a : 1 })
expect(result).toEqual({
a : 1,
b : 2,
})
})
test('changes an existing key', () => {
expect(assoc(
'a', 2, { a : 1 }
)).toEqual({ a : 2 })
})
test('undefined is considered an empty object', () => {
expect(assoc(
'a', 1, undefined
)).toEqual({ a : 1 })
})
test('null is considered an empty object', () => {
expect(assoc(
'a', 1, null
)).toEqual({ a : 1 })
})
test('value can be null', () => {
expect(assoc(
'a', null, null
)).toEqual({ a : null })
})
test('value can be undefined', () => {
expect(assoc(
'a', undefined, null
)).toEqual({ a : undefined })
})
test('assignment is shallow', () => {
expect(assoc(
'a', { b : 2 }, { a : { c : 3 } }
)).toEqual({ a : { b : 2 } })
})
Typescript test
import {assoc} from 'rambda'
const obj = {a: 1}
const newValue = 2
const newProp = 'b'
describe('R.assoc', () => {
it('happy', () => {
const result = assoc(newProp, newValue, obj)
result.a
result.b
})
it('curried 1', () => {
const result = assoc(newProp, newValue)(obj)
result.a
result.b
})
it('curried 2', () => {
const result = assoc(newProp)(newValue)(obj)
result.a
result.b
})
})
Lodash is fastest. Rambda is 72.32% slower and Ramda is 60.08% slower
const R = require('../../dist/rambda.js')
const input = {
a : 1,
b : 2,
}
const key = 'c'
const value = 3
const assoc = [
{
label : 'Rambda',
fn : () => {
R.assoc(
key, value, input
)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.assoc(
key, value, input
)
},
},
{
label : 'Lodash.set',
fn : () => {
_.set(
input, key, value
)
},
},
]
assocPath
assocPath<Output>(path: Path, newValue: any, obj: object): Output
It makes a shallow clone of obj
with setting or overriding with newValue
the property found with path
.
All Typescript definitions
assocPath<Output>(path: Path, newValue: any, obj: object): Output;
assocPath<Output>(path: Path, newValue: any): (obj: object) => Output;
assocPath<Output>(path: Path): (newValue: any) => (obj: object) => Output;
R.assocPath source
import { _isArray } from './_internals/_isArray.js'
import { _isInteger } from './_internals/_isInteger.js'
import { cloneList } from './_internals/cloneList.js'
import { assoc } from './assoc.js'
import { curry } from './curry.js'
function assocPathFn(
path, newValue, input
){
const pathArrValue =
typeof path === 'string' ?
path.split('.').map(x => _isInteger(Number(x)) ? Number(x) : x) :
path
if (pathArrValue.length === 0){
return newValue
}
const index = pathArrValue[ 0 ]
if (pathArrValue.length > 1){
const condition =
typeof input !== 'object' ||
input === null ||
!input.hasOwnProperty(index)
const nextinput = condition ?
_isInteger(pathArrValue[ 1 ]) ?
[] :
{} :
input[ index ]
newValue = assocPathFn(
Array.prototype.slice.call(pathArrValue, 1),
newValue,
nextinput
)
}
if (_isInteger(index) && _isArray(input)){
const arr = cloneList(input)
arr[ index ] = newValue
return arr
}
return assoc(
index, newValue, input
)
}
export const assocPath = curry(assocPathFn)
Tests
import { assocPath } from './assocPath.js'
test('string can be used as path input', () => {
const testObj = {
a : [ { b : 1 }, { b : 2 } ],
d : 3,
}
const result = assocPath(
'a.0.b', 10, testObj
)
const expected = {
a : [ { b : 10 }, { b : 2 } ],
d : 3,
}
expect(result).toEqual(expected)
})
test('bug', () => {
const state = {}
const withDateLike = assocPath(
[ 'outerProp', '2020-03-10' ],
{ prop : 2 },
state
)
const withNumber = assocPath(
[ 'outerProp', '5' ], { prop : 2 }, state
)
const withDateLikeExpected = { outerProp : { '2020-03-10' : { prop : 2 } } }
const withNumberExpected = { outerProp : { 5 : { prop : 2 } } }
expect(withDateLike).toEqual(withDateLikeExpected)
expect(withNumber).toEqual(withNumberExpected)
})
test('adds a key to an empty object', () => {
expect(assocPath(
[ 'a' ], 1, {}
)).toEqual({ a : 1 })
})
test('adds a key to a non-empty object', () => {
expect(assocPath(
'b', 2, { a : 1 }
)).toEqual({
a : 1,
b : 2,
})
})
test('adds a nested key to a non-empty object', () => {
expect(assocPath(
'b.c', 2, { a : 1 }
)).toEqual({
a : 1,
b : { c : 2 },
})
})
test('adds a nested key to a nested non-empty object - curry case 1', () => {
expect(assocPath('b.d',
3)({
a : 1,
b : { c : 2 },
})).toEqual({
a : 1,
b : {
c : 2,
d : 3,
},
})
})
test('adds a key to a non-empty object - curry case 1', () => {
expect(assocPath('b', 2)({ a : 1 })).toEqual({
a : 1,
b : 2,
})
})
test('adds a nested key to a non-empty object - curry case 1', () => {
expect(assocPath('b.c', 2)({ a : 1 })).toEqual({
a : 1,
b : { c : 2 },
})
})
test('adds a key to a non-empty object - curry case 2', () => {
expect(assocPath('b')(2, { a : 1 })).toEqual({
a : 1,
b : 2,
})
})
test('adds a key to a non-empty object - curry case 3', () => {
const result = assocPath('b')(2)({ a : 1 })
expect(result).toEqual({
a : 1,
b : 2,
})
})
test('changes an existing key', () => {
expect(assocPath(
'a', 2, { a : 1 }
)).toEqual({ a : 2 })
})
test('undefined is considered an empty object', () => {
expect(assocPath(
'a', 1, undefined
)).toEqual({ a : 1 })
})
test('null is considered an empty object', () => {
expect(assocPath(
'a', 1, null
)).toEqual({ a : 1 })
})
test('value can be null', () => {
expect(assocPath(
'a', null, null
)).toEqual({ a : null })
})
test('value can be undefined', () => {
expect(assocPath(
'a', undefined, null
)).toEqual({ a : undefined })
})
test('assignment is shallow', () => {
expect(assocPath(
'a', { b : 2 }, { a : { c : 3 } }
)).toEqual({ a : { b : 2 } })
})
test('empty array as path', () => {
const result = assocPath(
[], 3, {
a : 1,
b : 2,
}
)
expect(result).toEqual(3)
})
test('happy', () => {
const expected = { foo : { bar : { baz : 42 } } }
const result = assocPath(
[ 'foo', 'bar', 'baz' ], 42, { foo : null }
)
expect(result).toEqual(expected)
})
Typescript test
import {assocPath} from 'rambda'
interface Output {
a: number
foo: {bar: number}
}
describe('R.assocPath - user must explicitly set type of output', () => {
it('with array as path input', () => {
const result = assocPath<Output>(['foo', 'bar'], 2, {a: 1})
result
})
it('with string as path input', () => {
const result = assocPath<Output>('foo.bar', 2, {a: 1})
result
})
})
describe('R.assocPath - curried', () => {
it('with array as path input', () => {
const result = assocPath<Output>(['foo', 'bar'], 2)({a: 1})
result
})
it('with string as path input', () => {
const result = assocPath<Output>('foo.bar', 2)({a: 1})
result
})
})
bind
bind<F extends (...args: any[]) => any, T>(fn: F, thisObj: T): (...args: Parameters<F>) => ReturnType<F>
Creates a function that is bound to a context.
All Typescript definitions
bind<F extends (...args: any[]) => any, T>(fn: F, thisObj: T): (...args: Parameters<F>) => ReturnType<F>;
bind<F extends (...args: any[]) => any, T>(fn: F): (thisObj: T) => (...args: Parameters<F>) => ReturnType<F>;
R.bind source
import { curryN } from './curryN.js'
export function bind(fn, thisObj){
if (arguments.length === 1){
return _thisObj => bind(fn, _thisObj)
}
return curryN(fn.length, (...args) => fn.apply(thisObj, args))
}
Tests
import {bind} from './bind.js'
function Foo(x) {
this.x = x
}
function add(x) {
return this.x + x
}
function Bar(x, y) {
this.x = x
this.y = y
}
Bar.prototype = new Foo()
Bar.prototype.getX = function () {
return 'prototype getX'
}
test('returns a function', () => {
expect(typeof bind(add)(Foo)).toEqual('function')
})
test('returns a function bound to the specified context object', () => {
const f = new Foo(12)
function isFoo() {
return this instanceof Foo
}
const isFooBound = bind(isFoo, f)
expect(isFoo()).toBeFalse()
expect(isFooBound()).toBeTrue()
})
test('works with built-in types', () => {
const abc = bind(String.prototype.toLowerCase, 'ABCDEFG')
expect(typeof abc).toEqual('function')
expect(abc()).toEqual('abcdefg')
})
test('works with user-defined types', () => {
const f = new Foo(12)
function getX() {
return this.x
}
const getXFooBound = bind(getX, f)
expect(getXFooBound()).toEqual(12)
})
test('works with plain objects', () => {
const pojso = {x: 100}
function incThis() {
return this.x + 1
}
const incPojso = bind(incThis, pojso)
expect(typeof incPojso).toEqual('function')
expect(incPojso()).toEqual(101)
})
test('does not interfere with existing object methods', () => {
const b = new Bar('a', 'b')
function getX() {
return this.x
}
const getXBarBound = bind(getX, b)
expect(b.getX()).toEqual('prototype getX')
expect(getXBarBound()).toEqual('a')
})
test('preserves arity', () => {
const f0 = function () {
return 0
}
const f1 = function (a) {
return a
}
const f2 = function (a, b) {
return a + b
}
const f3 = function (a, b, c) {
return a + b + c
}
expect(bind(f0, {}).length).toEqual(0)
expect(bind(f1, {}).length).toEqual(1)
expect(bind(f2, {}).length).toEqual(2)
expect(bind(f3, {}).length).toEqual(3)
})
Typescript test
import {bind} from 'rambda'
class Foo {}
function isFoo<T = any>(this: T): boolean {
return this instanceof Foo
}
describe('R.bind', () => {
it('happy', () => {
const foo = new Foo()
const result = bind(isFoo, foo)()
result
})
})
both
both(pred1: Pred, pred2: Pred): Pred
It returns a function with input
argument.
This function will return true
, if both firstCondition
and secondCondition
return true
when input
is passed as their argument.
All Typescript definitions
both(pred1: Pred, pred2: Pred): Pred;
both<T>(pred1: Predicate<T>, pred2: Predicate<T>): Predicate<T>;
both<T>(pred1: Predicate<T>): (pred2: Predicate<T>) => Predicate<T>;
both(pred1: Pred): (pred2: Pred) => Pred;
R.both source
export function both(f, g){
if (arguments.length === 1) return _g => both(f, _g)
return (...input) => f(...input) && g(...input)
}
Tests
import { both } from './both.js'
const firstFn = val => val > 0
const secondFn = val => val < 10
test('with curry', () => {
expect(both(firstFn)(secondFn)(17)).toBeFalse()
})
test('without curry', () => {
expect(both(firstFn, secondFn)(7)).toBeTrue()
})
test('with multiple inputs', () => {
const between = function (
a, b, c
){
return a < b && b < c
}
const total20 = function (
a, b, c
){
return a + b + c === 20
}
const fn = both(between, total20)
expect(fn(
5, 7, 8
)).toBeTrue()
})
test('skip evaluation of the second expression', () => {
let effect = 'not evaluated'
const F = function (){
return false
}
const Z = function (){
effect = 'Z got evaluated'
}
both(F, Z)()
expect(effect).toBe('not evaluated')
})
Typescript test
import {both} from 'rambda'
describe('R.both', () => {
it('with passed type', () => {
const fn = both<number>(
x => x > 1,
x => x % 2 === 0
)
fn
const result = fn(2)
result
})
it('with passed type - curried', () => {
const fn = both<number>(x => x > 1)(x => x % 2 === 0)
fn
const result = fn(2)
result
})
it('no type passed', () => {
const fn = both(
x => {
x
return x > 1
},
x => {
x
return x % 2 === 0
}
)
const result = fn(2)
result
})
it('no type passed - curried', () => {
const fn = both((x: number) => {
x
return x > 1
})((x: number) => {
x
return x % 2 === 0
})
const result = fn(2)
result
})
})
chain
chain<T, U>(fn: (n: T) => U[], list: T[]): U[]
The method is also known as flatMap
.
All Typescript definitions
chain<T, U>(fn: (n: T) => U[], list: T[]): U[];
chain<T, U>(fn: (n: T) => U[]): (list: T[]) => U[];
R.chain source
export function chain(fn, list){
if (arguments.length === 1){
return _list => chain(fn, _list)
}
return [].concat(...list.map(fn))
}
Tests
import { chain as chainRamda } from 'ramda'
import { chain } from './chain.js'
const duplicate = n => [ n, n ]
test('happy', () => {
const fn = x => [ x * 2 ]
const list = [ 1, 2, 3 ]
const result = chain(fn, list)
expect(result).toEqual([ 2, 4, 6 ])
})
test('maps then flattens one level', () => {
expect(chain(duplicate, [ 1, 2, 3 ])).toEqual([ 1, 1, 2, 2, 3, 3 ])
})
test('maps then flattens one level - curry', () => {
expect(chain(duplicate)([ 1, 2, 3 ])).toEqual([ 1, 1, 2, 2, 3, 3 ])
})
test('flattens only one level', () => {
const nest = n => [ [ n ] ]
expect(chain(nest, [ 1, 2, 3 ])).toEqual([ [ 1 ], [ 2 ], [ 3 ] ])
})
test('can compose', () => {
function dec(x){
return [ x - 1 ]
}
function times2(x){
return [ x * 2 ]
}
const mdouble = chain(times2)
const mdec = chain(dec)
expect(mdec(mdouble([ 10, 20, 30 ]))).toEqual([ 19, 39, 59 ])
})
test('@types/ramda broken test', () => {
const score = {
maths : 90,
physics : 80,
}
const calculateTotal = score => {
const { maths, physics } = score
return maths + physics
}
const assocTotalToScore = (total, score) => ({
...score,
total,
})
const calculateAndAssocTotalToScore = chainRamda(assocTotalToScore,
calculateTotal)
expect(() => calculateAndAssocTotalToScore(score)).toThrow()
})
Typescript test
import {chain} from 'rambda'
const list = [1, 2, 3]
const fn = (x: number) => [`${x}`, `${x}`]
describe('R.chain', () => {
it('without passing type', () => {
const result = chain(fn, list)
result
const curriedResult = chain(fn)(list)
curriedResult
})
})
clamp
Restrict a number input
to be within min
and max
limits.
If input
is bigger than max
, then the result is max
.
If input
is smaller than min
, then the result is min
.
clone
It creates a deep copy of the input
, which may contain (nested) Arrays and Objects, Numbers, Strings, Booleans and Dates.
complement
It returns inverted
version of origin
function that accept input
as argument.
The return value of inverted
is the negative boolean value of origin(input)
.
compose
It performs right-to-left function composition.
concat
It returns a new string or array, which is the result of merging x
and y
.
cond
It takes list with conditions
and returns a new function fn
that expects input
as argument.
This function will start evaluating the conditions
in order to find the first winner(order of conditions matter).
The winner is this condition, which left side returns true
when input
is its argument. Then the evaluation of the right side of the winner will be the final result.
If no winner is found, then fn
returns undefined
.
converge
Accepts a converging function and a list of branching functions and returns a new function. When invoked, this new function is applied to some arguments, each branching function is applied to those same arguments. The results of each branching function are passed as arguments to the converging function to produce the return value.
count
It counts how many times predicate
function returns true
, when supplied with iteration of list
.
countBy
countBy<T extends unknown>(transformFn: (x: T) => any, list: T[]): Record<string, number>
It counts elements in a list after each instance of the input list is passed through transformFn
function.
All Typescript definitions
countBy<T extends unknown>(transformFn: (x: T) => any, list: T[]): Record<string, number>;
countBy<T extends unknown>(transformFn: (x: T) => any): (list: T[]) => Record<string, number>;
R.countBy source
export function countBy(fn, list){
if (arguments.length === 1){
return _list => countBy(fn, _list)
}
const willReturn = {}
list.forEach(item => {
const key = fn(item)
if (!willReturn[ key ]){
willReturn[ key ] = 1
} else {
willReturn[ key ]++
}
})
return willReturn
}
Tests
import { countBy } from './countBy.js'
const list = [ 'a', 'A', 'b', 'B', 'c', 'C' ]
test('happy', () => {
const result = countBy(x => x.toLowerCase(), list)
expect(result).toEqual({
a : 2,
b : 2,
c : 2,
})
})
Typescript test
import { countBy } from 'rambda'
const transformFn = (x: string) => x.toLowerCase()
const list = [ 'a', 'A', 'b', 'B', 'c', 'C' ]
describe('R.countBy', () => {
it('happy', () => {
const result = countBy(transformFn, list)
result
})
it('curried', () => {
const result = countBy(transformFn)(list)
result
})
})
curry
It expects a function as input and returns its curried version.
curryN
It returns a curried equivalent of the provided function, with the specified arity.
dec
It decrements a number.
defaultTo
defaultTo<T>(defaultValue: T, input: T | null | undefined): T
It returns defaultValue
, if all of inputArguments
are undefined
, null
or NaN
.
Else, it returns the first truthy inputArguments
instance(from left to right).
All Typescript definitions
defaultTo<T>(defaultValue: T, input: T | null | undefined): T;
defaultTo<T>(defaultValue: T): (input: T | null | undefined) => T;
R.defaultTo source
function isFalsy(input){
return (
input === undefined || input === null || Number.isNaN(input) === true
)
}
export function defaultTo(defaultArgument, input){
if (arguments.length === 1){
return _input => defaultTo(defaultArgument, _input)
}
return isFalsy(input) ? defaultArgument : input
}
Tests
import {defaultTo} from './defaultTo.js'
test('with undefined', () => {
expect(defaultTo('foo')(undefined)).toEqual('foo')
})
test('with null', () => {
expect(defaultTo('foo')(null)).toEqual('foo')
})
test('with NaN', () => {
expect(defaultTo('foo')(NaN)).toEqual('foo')
})
test('with empty string', () => {
expect(defaultTo('foo', '')).toEqual('')
})
test('with false', () => {
expect(defaultTo('foo', false)).toBeFalse()
})
test('when inputArgument passes initial check', () => {
expect(defaultTo('foo', 'bar')).toEqual('bar')
})
Typescript test
import {defaultTo} from 'rambda'
describe('R.defaultTo with Ramda spec', () => {
it('happy', () => {
const result = defaultTo('foo', '')
result
})
it('with explicit type', () => {
const result = defaultTo<string>('foo', null)
result
})
})
Rambda is faster than Ramda with 48.91%
const R = require('../../dist/rambda.js')
const input = [ null, undefined, 5 ]
const defaultTo = [
{
label : 'Rambda',
fn : () => {
R.defaultTo(3, input[ 0 ])
},
},
{
label : 'Ramda',
fn : () => {
Ramda.defaultTo(3, input[ 0 ])
},
},
{
label : 'Rambda with multiple arguments',
fn : () => {
R.defaultTo(3, ...input)
},
},
]
difference
difference<T>(a: T[], b: T[]): T[]
It returns the uniq set of all elements in the first list a
not contained in the second list b
.
R.equals
is used to determine equality.
All Typescript definitions
difference<T>(a: T[], b: T[]): T[];
difference<T>(a: T[]): (b: T[]) => T[];
R.difference source
import { includes } from './includes.js'
import { uniq } from './uniq.js'
export function difference(a, b){
if (arguments.length === 1) return _b => difference(a, _b)
return uniq(a).filter(aInstance => !includes(aInstance, b))
}
Tests
import { difference as differenceRamda } from 'ramda'
import { difference } from './difference.js'
test('difference', () => {
const a = [ 1, 2, 3, 4 ]
const b = [ 3, 4, 5, 6 ]
expect(difference(a)(b)).toEqual([ 1, 2 ])
expect(difference([], [])).toEqual([])
})
test('difference with objects', () => {
const a = [ { id : 1 }, { id : 2 }, { id : 3 }, { id : 4 } ]
const b = [ { id : 3 }, { id : 4 }, { id : 5 }, { id : 6 } ]
expect(difference(a, b)).toEqual([ { id : 1 }, { id : 2 } ])
})
test('no duplicates in first list', () => {
const M2 = [ 1, 2, 3, 4, 1, 2, 3, 4 ]
const N2 = [ 3, 3, 4, 4, 5, 5, 6, 6 ]
expect(difference(M2, N2)).toEqual([ 1, 2 ])
})
test('should use R.equals', () => {
expect(difference([ 1 ], [ 1 ]).length).toEqual(0)
expect(differenceRamda([ NaN ], [ NaN ]).length).toEqual(0)
})
Typescript test
import {difference} from 'rambda'
const list1 = [1, 2, 3]
const list2 = [1, 2, 4]
describe('R.difference', () => {
it('happy', () => {
const result = difference(list1, list2)
result
})
it('curried', () => {
const result = difference(list1)(list2)
result
})
})
dissoc
It returns a new object that does not contain property prop
.
divide
drop
drop<T>(howMany: number, input: T[]): T[]
It returns howMany
items dropped from beginning of list or string input
.
All Typescript definitions
drop<T>(howMany: number, input: T[]): T[];
drop(howMany: number, input: string): string;
drop<T>(howMany: number): {
<T>(input: T[]): T[];
(input: string): string;
};
R.drop source
export function drop(howManyToDrop, listOrString){
if (arguments.length === 1) return _list => drop(howManyToDrop, _list)
return listOrString.slice(howManyToDrop > 0 ? howManyToDrop : 0)
}
Tests
import assert from 'assert'
import { drop } from './drop.js'
test('with array', () => {
expect(drop(2)([ 'foo', 'bar', 'baz' ])).toEqual([ 'baz' ])
expect(drop(3, [ 'foo', 'bar', 'baz' ])).toEqual([])
expect(drop(4, [ 'foo', 'bar', 'baz' ])).toEqual([])
})
test('with string', () => {
expect(drop(3, 'rambda')).toEqual('bda')
})
test('with non-positive count', () => {
expect(drop(0, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])
expect(drop(-1, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])
expect(drop(-Infinity, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])
})
test('should return copy', () => {
const xs = [ 1, 2, 3 ]
assert.notStrictEqual(drop(0, xs), xs)
assert.notStrictEqual(drop(-1, xs), xs)
})
Typescript test
import {drop} from 'rambda'
const list = [1, 2, 3, 4]
const str = 'foobar'
const howMany = 2
describe('R.drop - array', () => {
it('happy', () => {
const result = drop(howMany, list)
result
})
it('curried', () => {
const result = drop(howMany)(list)
result
})
})
describe('R.drop - string', () => {
it('happy', () => {
const result = drop(howMany, str)
result
})
it('curried', () => {
const result = drop(howMany)(str)
result
})
})
Rambda is faster than Ramda with 82.35%
const R = require('../../dist/rambda.js')
const input = [ 1, 2, 3, 4 ]
const drop = [
{
label : 'Rambda',
fn : () => {
R.drop(3, input)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.drop(3, input)
},
},
]
dropLast
dropLast<T>(howMany: number, input: T[]): T[]
It returns howMany
items dropped from the end of list or string input
.
All Typescript definitions
dropLast<T>(howMany: number, input: T[]): T[];
dropLast(howMany: number, input: string): string;
dropLast<T>(howMany: number): {
<T>(input: T[]): T[];
(input: string): string;
};
R.dropLast source
export function dropLast(howManyToDrop, listOrString){
if (arguments.length === 1){
return _listOrString => dropLast(howManyToDrop, _listOrString)
}
return howManyToDrop > 0 ?
listOrString.slice(0, -howManyToDrop) :
listOrString.slice()
}
Tests
import assert from 'assert'
import { dropLast } from './dropLast.js'
test('with array', () => {
expect(dropLast(2)([ 'foo', 'bar', 'baz' ])).toEqual([ 'foo' ])
expect(dropLast(3, [ 'foo', 'bar', 'baz' ])).toEqual([])
expect(dropLast(4, [ 'foo', 'bar', 'baz' ])).toEqual([])
})
test('with string', () => {
expect(dropLast(3, 'rambda')).toEqual('ram')
})
test('with non-positive count', () => {
expect(dropLast(0, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])
expect(dropLast(-1, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])
expect(dropLast(-Infinity, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])
})
test('should return copy', () => {
const xs = [ 1, 2, 3 ]
assert.notStrictEqual(dropLast(0, xs), xs)
assert.notStrictEqual(dropLast(-1, xs), xs)
})
Typescript test
import {dropLast} from 'rambda'
const list = [1, 2, 3, 4]
const str = 'foobar'
const howMany = 2
describe('R.dropLast - array', () => {
it('happy', () => {
const result = dropLast(howMany, list)
result
})
it('curried', () => {
const result = dropLast(howMany)(list)
result
})
})
describe('R.dropLast - string', () => {
it('happy', () => {
const result = dropLast(howMany, str)
result
})
it('curried', () => {
const result = dropLast(howMany)(str)
result
})
})
Rambda is faster than Ramda with 86.74%
const R = require('../../dist/rambda.js')
const input = [ 1, 2, 3, 4 ]
const dropLast = [
{
label : 'Rambda',
fn : () => {
R.dropLast(3, input)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.dropLast(3, input)
},
},
]
dropLastWhile
dropRepeats
dropRepeats<T>(list: T[]): T[]
It removes any successive duplicates according to R.equals
.
All Typescript definitions
dropRepeats<T>(list: T[]): T[];
R.dropRepeats source
import { _isArray } from './_internals/_isArray.js'
import { equals } from './equals.js'
export function dropRepeats(list){
if (!_isArray(list)){
throw new Error(`${ list } is not a list`)
}
const toReturn = []
list.reduce((prev, current) => {
if (!equals(prev, current)){
toReturn.push(current)
}
return current
}, undefined)
return toReturn
}
Tests
import { dropRepeats as dropRepeatsRamda } from 'ramda'
import { compareCombinations } from './_internals/testUtils.js'
import { add } from './add.js'
import { dropRepeats } from './dropRepeats.js'
const list = [ 1, 2, 2, 2, 3, 4, 4, 5, 5, 3, 2, 2, { a : 1 }, { a : 1 } ]
const listClean = [ 1, 2, 3, 4, 5, 3, 2, { a : 1 } ]
test('happy', () => {
const result = dropRepeats(list)
expect(result).toEqual(listClean)
})
const possibleLists = [
[ add(1), async () => {}, [ 1 ], [ 1 ], [ 2 ], [ 2 ] ],
[ add(1), add(1), add(2) ],
[],
1,
/foo/g,
Promise.resolve(1),
]
describe('brute force', () => {
compareCombinations({
firstInput : possibleLists,
callback : errorsCounters => {
expect(errorsCounters).toMatchInlineSnapshot(`
Object {
"ERRORS_MESSAGE_MISMATCH": 0,
"ERRORS_TYPE_MISMATCH": 0,
"RESULTS_MISMATCH": 1,
"SHOULD_NOT_THROW": 3,
"SHOULD_THROW": 0,
"TOTAL_TESTS": 6,
}
`)
},
fn : dropRepeats,
fnRamda : dropRepeatsRamda,
})
})
Typescript test
import {dropRepeats} from 'rambda'
describe('R.dropRepeats', () => {
it('happy', () => {
const result = dropRepeats([1, 2, 2, 3])
result
})
})
dropRepeatsWith
dropWhile
either
either(firstPredicate: Pred, secondPredicate: Pred): Pred
It returns a new predicate
function from firstPredicate
and secondPredicate
inputs.
This predicate
function will return true
, if any of the two input predicates return true
.
All Typescript definitions
either(firstPredicate: Pred, secondPredicate: Pred): Pred;
either<T>(firstPredicate: Predicate<T>, secondPredicate: Predicate<T>): Predicate<T>;
either<T>(firstPredicate: Predicate<T>): (secondPredicate: Predicate<T>) => Predicate<T>;
either(firstPredicate: Pred): (secondPredicate: Pred) => Pred;
R.either source
export function either(firstPredicate, secondPredicate){
if (arguments.length === 1){
return _secondPredicate => either(firstPredicate, _secondPredicate)
}
return (...input) =>
Boolean(firstPredicate(...input) || secondPredicate(...input))
}
Tests
import { either } from './either.js'
test('with multiple inputs', () => {
const between = function (
a, b, c
){
return a < b && b < c
}
const total20 = function (
a, b, c
){
return a + b + c === 20
}
const fn = either(between, total20)
expect(fn(
7, 8, 5
)).toBeTrue()
})
test('skip evaluation of the second expression', () => {
let effect = 'not evaluated'
const F = function (){
return true
}
const Z = function (){
effect = 'Z got evaluated'
}
either(F, Z)()
expect(effect).toBe('not evaluated')
})
test('case 1', () => {
const firstFn = val => val > 0
const secondFn = val => val * 5 > 10
expect(either(firstFn, secondFn)(1)).toBeTrue()
})
test('case 2', () => {
const firstFn = val => val > 0
const secondFn = val => val === -10
const fn = either(firstFn)(secondFn)
expect(fn(-10)).toBeTrue()
})
Typescript test
import {either} from 'rambda'
describe('R.either', () => {
it('with passed type', () => {
const fn = either<number>(
x => x > 1,
x => x % 2 === 0
)
fn
const result = fn(2)
result
})
it('with passed type - curried', () => {
const fn = either<number>(x => x > 1)(x => x % 2 === 0)
fn
const result = fn(2)
result
})
it('no type passed', () => {
const fn = either(
x => {
x
return x > 1
},
x => {
x
return x % 2 === 0
}
)
const result = fn(2)
result
})
it('no type passed - curried', () => {
const fn = either((x: number) => {
x
return x > 1
})((x: number) => {
x
return x % 2 === 0
})
const result = fn(2)
result
})
})
endsWith
endsWith(target: string, iterable: string): boolean
When iterable is a string, then it behaves as String.prototype.endsWith
.
When iterable is a list, then it uses R.equals to determine if the target list ends in the same way as the given target.
All Typescript definitions
endsWith(target: string, iterable: string): boolean;
endsWith(target: string): (iterable: string) => boolean;
endsWith<T>(target: T[], list: T[]): boolean;
endsWith<T>(target: T[]): (list: T[]) => boolean;
R.endsWith source
import { _isArray } from './_internals/_isArray.js'
import { equals } from './equals.js'
export function endsWith(target, iterable){
if (arguments.length === 1) return _iterable => endsWith(target, _iterable)
if (typeof iterable === 'string'){
return iterable.endsWith(target)
}
if (!_isArray(target)) return false
const diff = iterable.length - target.length
let correct = true
const filtered = target.filter((x, index) => {
if (!correct) return false
const result = equals(x, iterable[ index + diff ])
if (!result) correct = false
return result
})
return filtered.length === target.length
}
Tests
import { endsWith as endsWithRamda } from 'ramda'
import { compareCombinations } from './_internals/testUtils.js'
import { endsWith } from './endsWith.js'
test('with string', () => {
expect(endsWith('bar', 'foo-bar')).toBeTrue()
expect(endsWith('baz')('foo-bar')).toBeFalse()
})
test('use R.equals with array', () => {
const list = [ { a : 1 }, { a : 2 }, { a : 3 } ]
expect(endsWith({ a : 3 }, list)).toBeFalse(),
expect(endsWith([ { a : 3 } ], list)).toBeTrue()
expect(endsWith([ { a : 2 }, { a : 3 } ], list)).toBeTrue()
expect(endsWith(list, list)).toBeTrue()
expect(endsWith([ { a : 1 } ], list)).toBeFalse()
})
export const possibleTargets = [
NaN,
[ NaN ],
/foo/,
[ /foo/ ],
Promise.resolve(1),
[ Promise.resolve(1) ],
Error('foo'),
[ Error('foo') ],
]
export const possibleIterables = [
[ Promise.resolve(1), Promise.resolve(2) ],
[ /foo/, /bar/ ],
[ NaN ],
[ Error('foo'), Error('bar') ],
]
describe('brute force', () => {
compareCombinations({
fn : endsWith,
fnRamda : endsWithRamda,
firstInput : possibleTargets,
secondInput : possibleIterables,
callback : errorsCounters => {
expect(errorsCounters).toMatchInlineSnapshot(`
Object {
"ERRORS_MESSAGE_MISMATCH": 0,
"ERRORS_TYPE_MISMATCH": 0,
"RESULTS_MISMATCH": 0,
"SHOULD_NOT_THROW": 0,
"SHOULD_THROW": 0,
"TOTAL_TESTS": 32,
}
`)
},
})
})
Typescript test
import {endsWith} from 'rambda'
describe('R.endsWith - array as iterable', () => {
const target = [{a: 2}]
const iterable = [{a: 1}, {a: 2}]
it('happy', () => {
const result = endsWith(target, iterable)
result
})
it('curried', () => {
const result = endsWith(target)(iterable)
result
})
})
describe('R.endsWith - string as iterable', () => {
const target = 'bar'
const iterable = 'foo bar'
it('happy', () => {
const result = endsWith(target, iterable)
result
})
it('curried', () => {
const result = endsWith(target)(iterable)
result
})
})
eqProps
It returns true
if property prop
in obj1
is equal to property prop
in obj2
according to R.equals
.
equals
equals<T>(x: T, y: T): boolean
It deeply compares x
and y
and returns true
if they are equal.
All Typescript definitions
equals<T>(x: T, y: T): boolean;
equals<T>(x: T): (y: T) => boolean;
R.equals source
import { _isArray } from './_internals/_isArray.js'
import { type } from './type.js'
export function _lastIndexOf(valueToFind, list){
if (!_isArray(list)){
throw new Error(`Cannot read property 'indexOf' of ${ list }`)
}
const typeOfValue = type(valueToFind)
if (![ 'Object', 'Array', 'NaN', 'RegExp' ].includes(typeOfValue))
return list.lastIndexOf(valueToFind)
const { length } = list
let index = length
let foundIndex = -1
while (--index > -1 && foundIndex === -1){
if (equals(list[ index ], valueToFind)){
foundIndex = index
}
}
return foundIndex
}
export function _indexOf(valueToFind, list){
if (!_isArray(list)){
throw new Error(`Cannot read property 'indexOf' of ${ list }`)
}
const typeOfValue = type(valueToFind)
if (![ 'Object', 'Array', 'NaN', 'RegExp' ].includes(typeOfValue))
return list.indexOf(valueToFind)
let index = -1
let foundIndex = -1
const { length } = list
while (++index < length && foundIndex === -1){
if (equals(list[ index ], valueToFind)){
foundIndex = index
}
}
return foundIndex
}
function _arrayFromIterator(iter){
const list = []
let next
while (!(next = iter.next()).done){
list.push(next.value)
}
return list
}
function _equalsSets(a, b){
if (a.size !== b.size){
return false
}
const aList = _arrayFromIterator(a.values())
const bList = _arrayFromIterator(b.values())
const filtered = aList.filter(aInstance => _indexOf(aInstance, bList) === -1)
return filtered.length === 0
}
function parseError(maybeError){
const typeofError = maybeError.__proto__.toString()
if (![ 'Error', 'TypeError' ].includes(typeofError)) return []
return [ typeofError, maybeError.message ]
}
function parseDate(maybeDate){
if (!maybeDate.toDateString) return [ false ]
return [ true, maybeDate.getTime() ]
}
function parseRegex(maybeRegex){
if (maybeRegex.constructor !== RegExp) return [ false ]
return [ true, maybeRegex.toString() ]
}
function equalsSets(a, b){
if (a.size !== b.size){
return false
}
const aList = _arrayFromIterator(a.values())
const bList = _arrayFromIterator(b.values())
const filtered = aList.filter(aInstance => _indexOf(aInstance, bList) === -1)
return filtered.length === 0
}
export function equals(a, b){
if (arguments.length === 1) return _b => equals(a, _b)
const aType = type(a)
if (aType !== type(b)) return false
if (aType === 'Function'){
return a.name === undefined ? false : a.name === b.name
}
if ([ 'NaN', 'Undefined', 'Null' ].includes(aType)) return true
if (aType === 'Number'){
if (Object.is(-0, a) !== Object.is(-0, b)) return false
return a.toString() === b.toString()
}
if ([ 'String', 'Boolean' ].includes(aType)){
return a.toString() === b.toString()
}
if (aType === 'Array'){
const aClone = Array.from(a)
const bClone = Array.from(b)
if (aClone.toString() !== bClone.toString()){
return false
}
let loopArrayFlag = true
aClone.forEach((aCloneInstance, aCloneIndex) => {
if (loopArrayFlag){
if (
aCloneInstance !== bClone[ aCloneIndex ] &&
!equals(aCloneInstance, bClone[ aCloneIndex ])
){
loopArrayFlag = false
}
}
})
return loopArrayFlag
}
const aRegex = parseRegex(a)
const bRegex = parseRegex(b)
if (aRegex[ 0 ]){
return bRegex[ 0 ] ? aRegex[ 1 ] === bRegex[ 1 ] : false
} else if (bRegex[ 0 ]) return false
const aDate = parseDate(a)
const bDate = parseDate(b)
if (aDate[ 0 ]){
return bDate[ 0 ] ? aDate[ 1 ] === bDate[ 1 ] : false
} else if (bDate[ 0 ]) return false
const aError = parseError(a)
const bError = parseError(b)
if (aError[ 0 ]){
return bError[ 0 ] ?
aError[ 0 ] === bError[ 0 ] && aError[ 1 ] === bError[ 1 ] :
false
}
if (aType === 'Set'){
return _equalsSets(a, b)
}
if (aType === 'Object'){
const aKeys = Object.keys(a)
if (aKeys.length !== Object.keys(b).length){
return false
}
let loopObjectFlag = true
aKeys.forEach(aKeyInstance => {
if (loopObjectFlag){
const aValue = a[ aKeyInstance ]
const bValue = b[ aKeyInstance ]
if (aValue !== bValue && !equals(aValue, bValue)){
loopObjectFlag = false
}
}
})
return loopObjectFlag
}
return false
}
Tests
import {equals as equalsRamda} from 'ramda'
import {compareCombinations} from './_internals/testUtils.js'
import {variousTypes} from './benchmarks/_utils.js'
import {equals} from './equals.js'
test('compare functions', () => {
function foo() {}
function bar() {}
const baz = () => {}
const expectTrue = equals(foo, foo)
const expectFalseFirst = equals(foo, bar)
const expectFalseSecond = equals(foo, baz)
expect(expectTrue).toBeTrue()
expect(expectFalseFirst).toBeFalse()
expect(expectFalseSecond).toBeFalse()
})
test('with array of objects', () => {
const list1 = [{a: 1}, [{b: 2}]]
const list2 = [{a: 1}, [{b: 2}]]
const list3 = [{a: 1}, [{b: 3}]]
expect(equals(list1, list2)).toBeTrue()
expect(equals(list1, list3)).toBeFalse()
})
test('with regex', () => {
expect(equals(/s/, /s/)).toBeTrue()
expect(equals(/s/, /d/)).toBeFalse()
expect(equals(/a/gi, /a/gi)).toBeTrue()
expect(equals(/a/gim, /a/gim)).toBeTrue()
expect(equals(/a/gi, /a/i)).toBeFalse()
})
test('not a number', () => {
expect(equals([NaN], [NaN])).toBeTrue()
})
test('new number', () => {
expect(equals(new Number(0), new Number(0))).toBeTrue()
expect(equals(new Number(0), new Number(1))).toBeFalse()
expect(equals(new Number(1), new Number(0))).toBeFalse()
})
test('new string', () => {
expect(equals(new String(''), new String(''))).toBeTrue()
expect(equals(new String(''), new String('x'))).toBeFalse()
expect(equals(new String('x'), new String(''))).toBeFalse()
expect(equals(new String('foo'), new String('foo'))).toBeTrue()
expect(equals(new String('foo'), new String('bar'))).toBeFalse()
expect(equals(new String('bar'), new String('foo'))).toBeFalse()
})
test('new Boolean', () => {
expect(equals(new Boolean(true), new Boolean(true))).toBeTrue()
expect(equals(new Boolean(false), new Boolean(false))).toBeTrue()
expect(equals(new Boolean(true), new Boolean(false))).toBeFalse()
expect(equals(new Boolean(false), new Boolean(true))).toBeFalse()
})
test('new Error', () => {
expect(equals(new Error('XXX'), {})).toBeFalse()
expect(equals(new Error('XXX'), new TypeError('XXX'))).toBeFalse()
expect(equals(new Error('XXX'), new Error('YYY'))).toBeFalse()
expect(equals(new Error('XXX'), new Error('XXX'))).toBeTrue()
expect(equals(new Error('XXX'), new TypeError('YYY'))).toBeFalse()
})
test('with dates', () => {
expect(equals(new Date(0), new Date(0))).toBeTrue()
expect(equals(new Date(1), new Date(1))).toBeTrue()
expect(equals(new Date(0), new Date(1))).toBeFalse()
expect(equals(new Date(1), new Date(0))).toBeFalse()
expect(equals(new Date(0), {})).toBeFalse()
expect(equals({}, new Date(0))).toBeFalse()
})
test('ramda spec', () => {
expect(equals({}, {})).toBeTrue()
expect(
equals(
{
a: 1,
b: 2,
},
{
a: 1,
b: 2,
}
)
).toBeTrue()
expect(
equals(
{
a: 2,
b: 3,
},
{
b: 3,
a: 2,
}
)
).toBeTrue()
expect(
equals(
{
a: 2,
b: 3,
},
{
a: 3,
b: 3,
}
)
).toBeFalse()
expect(
equals(
{
a: 2,
b: 3,
c: 1,
},
{
a: 2,
b: 3,
}
)
).toBeFalse()
})
test('works with boolean tuple', () => {
expect(equals([true, false], [true, false])).toBeTrue()
expect(equals([true, false], [true, true])).toBeFalse()
})
test('works with equal objects within array', () => {
const objFirst = {
a: {
b: 1,
c: 2,
d: [1],
},
}
const objSecond = {
a: {
b: 1,
c: 2,
d: [1],
},
}
const x = [1, 2, objFirst, null, '', []]
const y = [1, 2, objSecond, null, '', []]
expect(equals(x, y)).toBeTrue()
})
test('works with different objects within array', () => {
const objFirst = {a: {b: 1}}
const objSecond = {a: {b: 2}}
const x = [1, 2, objFirst, null, '', []]
const y = [1, 2, objSecond, null, '', []]
expect(equals(x, y)).toBeFalse()
})
test('works with undefined as second argument', () => {
expect(equals(1, undefined)).toBeFalse()
expect(equals(undefined, undefined)).toBeTrue()
})
test('compare sets', () => {
const toCompareDifferent = new Set([{a: 1}, {a: 2}])
const toCompareSame = new Set([{a: 1}, {a: 2}, {a: 1}])
const testSet = new Set([{a: 1}, {a: 2}, {a: 1}])
expect(equals(toCompareSame, testSet)).toBeTruthy()
expect(equals(toCompareDifferent, testSet)).toBeFalsy()
expect(equalsRamda(toCompareSame, testSet)).toBeTruthy()
expect(equalsRamda(toCompareDifferent, testSet)).toBeFalsy()
})
test('compare simple sets', () => {
const testSet = new Set(['2', '3', '3', '2', '1'])
expect(equals(new Set(['3', '2', '1']), testSet)).toBeTruthy()
expect(equals(new Set(['3', '2', '0']), testSet)).toBeFalsy()
})
test('various examples', () => {
expect(equals([1, 2, 3])([1, 2, 3])).toBeTrue()
expect(equals([1, 2, 3], [1, 2])).toBeFalse()
expect(equals(1, 1)).toBeTrue()
expect(equals(1, '1')).toBeFalse()
expect(equals({}, {})).toBeTrue()
expect(
equals(
{
a: 1,
b: 2,
},
{
b: 2,
a: 1,
}
)
).toBeTrue()
expect(
equals(
{
a: 1,
b: 2,
},
{
a: 1,
b: 1,
}
)
).toBeFalse()
expect(
equals(
{
a: 1,
b: false,
},
{
a: 1,
b: 1,
}
)
).toBeFalse()
expect(
equals(
{
a: 1,
b: 2,
},
{
b: 2,
a: 1,
c: 3,
}
)
).toBeFalse()
expect(
equals(
{
x: {
a: 1,
b: 2,
},
},
{
x: {
b: 2,
a: 1,
c: 3,
},
}
)
).toBeFalse()
expect(
equals(
{
a: 1,
b: 2,
},
{
b: 3,
a: 1,
}
)
).toBeFalse()
expect(equals({a: {b: {c: 1}}}, {a: {b: {c: 1}}})).toBeTrue()
expect(equals({a: {b: {c: 1}}}, {a: {b: {c: 2}}})).toBeFalse()
expect(equals({a: {}}, {a: {}})).toBeTrue()
expect(equals('', '')).toBeTrue()
expect(equals('foo', 'foo')).toBeTrue()
expect(equals('foo', 'bar')).toBeFalse()
expect(equals(0, false)).toBeFalse()
expect(equals(/\s/g, null)).toBeFalse()
expect(equals(null, null)).toBeTrue()
expect(equals(false)(null)).toBeFalse()
})
test('with custom functions', () => {
function foo() {
return 1
}
foo.prototype.toString = () => ''
const result = equals(foo, foo)
expect(result).toBeTrue()
})
test('with classes', () => {
class Foo {}
const foo = new Foo()
const result = equals(foo, foo)
expect(result).toBeTrue()
})
test('with negative zero', () => {
expect(equals(-0, -0)).toBeTrue()
expect(equals(-0, 0)).toBeFalse()
expect(equals(0, 0)).toBeTrue()
expect(equals(-0, 1)).toBeFalse()
})
const possibleInputs = variousTypes
describe('brute force', () => {
compareCombinations({
fn: equals,
fnRamda: equalsRamda,
firstInput: possibleInputs,
secondInput: possibleInputs,
callback: errorsCounters => {
expect(errorsCounters).toMatchInlineSnapshot(`
Object {
"ERRORS_MESSAGE_MISMATCH": 0,
"ERRORS_TYPE_MISMATCH": 0,
"RESULTS_MISMATCH": 5,
"SHOULD_NOT_THROW": 4,
"SHOULD_THROW": 0,
"TOTAL_TESTS": 289,
}
`)
},
})
})
Typescript test
import {equals} from 'rambda'
describe('R.equals', () => {
it('happy', () => {
const result = equals(4, 1)
result
})
it('with object', () => {
const foo = {a: 1}
const bar = {a: 2}
const result = equals(foo, bar)
result
})
it('curried', () => {
const result = equals(4)(1)
result
})
})
Lodash is fastest. Rambda is 58.37% slower and Ramda is 96.73% slower
const R = require('../../dist/rambda.js')
const limit = 10000
const strings = Array(limit)
.fill(null)
.map(() => Math.floor(Math.random() * 1000))
const equals = [
{
label : 'Rambda',
fn : () => {
strings.forEach(x => R.equals(x, 'ss'))
},
},
{
label : 'Ramda',
fn : () => {
strings.forEach(x => Ramda.equals(x, 'ss'))
},
},
{
label : 'Lodash',
fn : () => {
strings.forEach(x => _.isEqual(x, 'ss'))
},
},
]
evolve
evolve<T, U>(rules: ((x: T) => U)[], list: T[]): U[]
It takes object or array of functions as set of rules. These rules
are applied to the iterable
input to produce the result.
All Typescript definitions
evolve<T, U>(rules: ((x: T) => U)[], list: T[]): U[];
evolve<T, U>(rules: ((x: T) => U)[]) : (list: T[]) => U[];
evolve<E extends Evolver, V extends Evolvable<E>>(rules: E, obj: V): Evolve<V, E>;
evolve<E extends Evolver>(rules: E): <V extends Evolvable<E>>(obj: V) => Evolve<V, E>;
R.evolve source
import { _isArray } from './_internals/_isArray.js'
import { mapArray, mapObject } from './map.js'
import { type } from './type.js'
export function evolveArray(rules, list){
return mapArray(
(x, i) => {
if (type(rules[ i ]) === 'Function'){
return rules[ i ](x)
}
return x
},
list,
true
)
}
export function evolveObject(rules, iterable){
return mapObject((x, prop) => {
if (type(x) === 'Object'){
const typeRule = type(rules[ prop ])
if (typeRule === 'Function'){
return rules[ prop ](x)
}
if (typeRule === 'Object'){
return evolve(rules[ prop ], x)
}
return x
}
if (type(rules[ prop ]) === 'Function'){
return rules[ prop ](x)
}
return x
}, iterable)
}
export function evolve(rules, iterable){
if (arguments.length === 1){
return _iterable => evolve(rules, _iterable)
}
const rulesType = type(rules)
const iterableType = type(iterable)
if (iterableType !== rulesType){
throw new Error('iterableType !== rulesType')
}
if (![ 'Object', 'Array' ].includes(rulesType)){
throw new Error(`'iterable' and 'rules' are from wrong type ${ rulesType }`)
}
if (iterableType === 'Object'){
return evolveObject(rules, iterable)
}
return evolveArray(rules, iterable)
}
Tests
import { evolve as evolveRamda } from 'ramda'
import { add } from '../rambda.js'
import { compareCombinations, compareToRamda } from './_internals/testUtils.js'
import { evolve } from './evolve.js'
test('happy', () => {
const rules = {
foo : add(1),
nested : { bar : x => Object.keys(x).length },
}
const input = {
a : 1,
foo : 2,
nested : { bar : { z : 3 } },
}
const result = evolve(rules, input)
expect(result).toEqual({
a : 1,
foo : 3,
nested : { bar : 1 },
})
})
test('nested rule is wrong', () => {
const rules = {
foo : add(1),
nested : { bar : 10 },
}
const input = {
a : 1,
foo : 2,
nested : { bar : { z : 3 } },
}
const result = evolve(rules)(input)
expect(result).toEqual({
a : 1,
foo : 3,
nested : { bar : { z : 3 } },
})
})
test('is recursive', () => {
const rules = {
nested : {
second : add(-1),
third : add(1),
},
}
const object = {
first : 1,
nested : {
second : 2,
third : 3,
},
}
const expected = {
first : 1,
nested : {
second : 1,
third : 4,
},
}
const result = evolve(rules, object)
expect(result).toEqual(expected)
})
test('ignores primitive values', () => {
const rules = {
n : 2,
m : 'foo',
}
const object = {
n : 0,
m : 1,
}
const expected = {
n : 0,
m : 1,
}
const result = evolve(rules, object)
expect(result).toEqual(expected)
})
test('with array', () => {
const rules = [ add(1), add(-1) ]
const list = [ 100, 1400 ]
const expected = [ 101, 1399 ]
const result = evolve(rules, list)
expect(result).toEqual(expected)
})
const rulesObject = { a : add(1) }
const rulesList = [ add(1) ]
const possibleIterables = [ null, undefined, '', 42, [], [ 1 ], { a : 1 } ]
const possibleRules = [ ...possibleIterables, rulesList, rulesObject ]
describe('brute force', () => {
compareCombinations({
firstInput : possibleRules,
callback : errorsCounters => {
expect(errorsCounters).toMatchInlineSnapshot(`
Object {
"ERRORS_MESSAGE_MISMATCH": 0,
"ERRORS_TYPE_MISMATCH": 4,
"RESULTS_MISMATCH": 0,
"SHOULD_NOT_THROW": 51,
"SHOULD_THROW": 0,
"TOTAL_TESTS": 63,
}
`)
},
secondInput : possibleIterables,
fn : evolve,
fnRamda : evolveRamda,
})
})
Typescript test
import {evolve, add} from 'rambda'
describe('R.evolve', () => {
it('happy', () => {
const input = {
foo: 2,
nested: {
a: 1,
bar: 3,
},
}
const rules = {
foo: add(1),
nested: {
a: add(-1),
bar: add(1),
},
}
const result = evolve(rules, input)
const curriedResult = evolve(rules)(input)
result.nested.a
curriedResult.nested.a
result.nested.bar
result.foo
})
it('with array', () => {
const rules = [String, String]
const input = [100, 1400]
const result = evolve(rules, input)
const curriedResult = evolve(rules)(input)
result
curriedResult
})
})
F
F(): boolean
All Typescript definitions
F(): boolean;
R.F source
export function F(){
return false
}
filter
filter<T>(predicate: Predicate<T>): (input: T[]) => T[]
It filters list or object input
using a predicate
function.
All Typescript definitions
filter<T>(predicate: Predicate<T>): (input: T[]) => T[];
filter<T>(predicate: Predicate<T>, input: T[]): T[];
filter<T, U>(predicate: ObjectPredicate<T>): (x: Dictionary<T>) => Dictionary<T>;
filter<T>(predicate: ObjectPredicate<T>, x: Dictionary<T>): Dictionary<T>;
R.filter source
import { _isArray } from './_internals/_isArray.js'
export function filterObject(predicate, obj){
const willReturn = {}
for (const prop in obj){
if (predicate(
obj[ prop ], prop, obj
)){
willReturn[ prop ] = obj[ prop ]
}
}
return willReturn
}
export function filterArray(
predicate, list, indexed = false
){
let index = 0
const len = list.length
const willReturn = []
while (index < len){
const predicateResult = indexed ?
predicate(list[ index ], index) :
predicate(list[ index ])
if (predicateResult){
willReturn.push(list[ index ])
}
index++
}
return willReturn
}
export function filter(predicate, iterable){
if (arguments.length === 1)
return _iterable => filter(predicate, _iterable)
if (!iterable){
throw new Error('Incorrect iterable input')
}
if (_isArray(iterable)) return filterArray(
predicate, iterable, false
)
return filterObject(predicate, iterable)
}
Tests
import { filter as filterRamda } from 'ramda'
import { filter } from './filter.js'
import { T } from './T.js'
const sampleObject = {
a : 1,
b : 2,
c : 3,
d : 4,
}
test('happy', () => {
const isEven = n => n % 2 === 0
expect(filter(isEven, [ 1, 2, 3, 4 ])).toEqual([ 2, 4 ])
expect(filter(isEven, {
a : 1,
b : 2,
d : 3,
})).toEqual({ b : 2 })
})
test('predicate when input is object', () => {
const obj = {
a : 1,
b : 2,
}
const predicate = (
val, prop, inputObject
) => {
expect(inputObject).toEqual(obj)
expect(typeof prop).toEqual('string')
return val < 2
}
expect(filter(predicate, obj)).toEqual({ a : 1 })
})
test('with object', () => {
const isEven = n => n % 2 === 0
const result = filter(isEven, sampleObject)
const expectedResult = {
b : 2,
d : 4,
}
expect(result).toEqual(expectedResult)
})
test('bad inputs difference between Ramda and Rambda', () => {
expect(() => filter(T, null)).toThrowWithMessage(Error,
'Incorrect iterable input')
expect(() => filter(T)(undefined)).toThrowWithMessage(Error,
'Incorrect iterable input')
expect(() => filterRamda(T, null)).toThrowWithMessage(TypeError,
'Cannot read properties of null (reading \'fantasy-land/filter\')')
expect(() => filterRamda(T, undefined)).toThrowWithMessage(TypeError,
'Cannot read properties of undefined (reading \'fantasy-land/filter\')')
})
Typescript test
import {filter} from 'rambda'
const list = [1, 2, 3]
const obj = {a: 1, b: 2}
describe('R.filter with array', () => {
it('happy', () => {
const result = filter<number>(x => {
x
return x > 1
}, list)
result
})
it('curried', () => {
const result = filter<number>(x => {
x
return x > 1
})(list)
result
})
})
describe('R.filter with objects', () => {
it('happy', () => {
const result = filter<number>((val, prop, origin) => {
val
prop
origin
return val > 1
}, obj)
result
})
it('curried version requires second dummy type', () => {
const result = filter<number, any>((val, prop, origin) => {
val
prop
origin
return val > 1
})(obj)
result
})
})
Lodash is fastest. Rambda is 6.7% slower and Ramda is 72.03% slower
const R = require('../../dist/rambda.js')
const arr = [ 1, 2, 3, 4 ]
const fn = x => x > 2
const filter = [
{
label : 'Rambda',
fn : () => {
R.filter(fn, arr)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.filter(fn, arr)
},
},
{
label : 'Lodash',
fn : () => {
_.filter(arr, fn)
},
},
]
find
find<T>(predicate: (x: T) => boolean, list: T[]): T | undefined
It returns the first element of list
that satisfy the predicate
.
If there is no such element, it returns undefined
.
All Typescript definitions
find<T>(predicate: (x: T) => boolean, list: T[]): T | undefined;
find<T>(predicate: (x: T) => boolean): (list: T[]) => T | undefined;
R.find source
export function find(predicate, list){
if (arguments.length === 1) return _list => find(predicate, _list)
let index = 0
const len = list.length
while (index < len){
const x = list[ index ]
if (predicate(x)){
return x
}
index++
}
}
Tests
import { find } from './find.js'
import { propEq } from './propEq.js'
const list = [ { a : 1 }, { a : 2 }, { a : 3 } ]
test('happy', () => {
const fn = propEq('a', 2)
expect(find(fn, list)).toEqual({ a : 2 })
})
test('with curry', () => {
const fn = propEq('a', 4)
expect(find(fn)(list)).toBeUndefined()
})
test('with empty list', () => {
expect(find(() => true, [])).toBeUndefined()
})
Typescript test
import {find} from 'rambda'
const list = [1, 2, 3]
describe('R.find', () => {
it('happy', () => {
const predicate = (x: number) => x > 2
const result = find(predicate, list)
result
})
it('curried', () => {
const predicate = (x: number) => x > 2
const result = find(predicate)(list)
result
})
})
Rambda is fastest. Ramda is 85.14% slower and Lodash is 42.65% slower
const R = require('../../dist/rambda.js')
const fn = x => x > 2
const list = [ 1, 2, 3, 4 ]
const find = [
{
label : 'Rambda',
fn : () => {
R.find(fn, list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.find(fn, list)
},
},
{
label : 'Lodash',
fn : () => {
_.find(list, fn)
},
},
]
findIndex
findIndex<T>(predicate: (x: T) => boolean, list: T[]): number
It returns the index of the first element of list
satisfying the predicate
function.
If there is no such element, then -1
is returned.
All Typescript definitions
findIndex<T>(predicate: (x: T) => boolean, list: T[]): number;
findIndex<T>(predicate: (x: T) => boolean): (list: T[]) => number;
R.findIndex source
export function findIndex(predicate, list){
if (arguments.length === 1) return _list => findIndex(predicate, _list)
const len = list.length
let index = -1
while (++index < len){
if (predicate(list[ index ])){
return index
}
}
return -1
}
Tests
import { findIndex } from './findIndex.js'
import { propEq } from './propEq.js'
const list = [ { a : 1 }, { a : 2 }, { a : 3 } ]
test('happy', () => {
expect(findIndex(propEq('a', 2), list)).toEqual(1)
expect(findIndex(propEq('a', 1))(list)).toEqual(0)
expect(findIndex(propEq('a', 4))(list)).toEqual(-1)
})
Typescript test
import {findIndex} from 'rambda'
const list = [1, 2, 3]
describe('R.findIndex', () => {
it('happy', () => {
const predicate = (x: number) => x > 2
const result = findIndex(predicate, list)
result
})
it('curried', () => {
const predicate = (x: number) => x > 2
const result = findIndex(predicate)(list)
result
})
})
Rambda is fastest. Ramda is 86.48% slower and Lodash is 72.27% slower
const R = require('../../dist/rambda.js')
const fn = x => x > 2
const list = [ 1, 2, 3, 4 ]
const findIndex = [
{
label : 'Rambda',
fn : () => {
R.findIndex(fn, list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.findIndex(fn, list)
},
},
{
label : 'Lodash',
fn : () => {
_.findIndex(list, fn)
},
},
]
findLast
findLast<T>(fn: (x: T) => boolean, list: T[]): T | undefined
It returns the last element of list
satisfying the predicate
function.
If there is no such element, then undefined
is returned.
All Typescript definitions
findLast<T>(fn: (x: T) => boolean, list: T[]): T | undefined;
findLast<T>(fn: (x: T) => boolean): (list: T[]) => T | undefined;
R.findLast source
export function findLast(predicate, list){
if (arguments.length === 1) return _list => findLast(predicate, _list)
let index = list.length
while (--index >= 0){
if (predicate(list[ index ])){
return list[ index ]
}
}
return undefined
}
Tests
import { findLast } from './findLast.js'
test('happy', () => {
const result = findLast(x => x > 1, [ 1, 1, 1, 2, 3, 4, 1 ])
expect(result).toEqual(4)
expect(findLast(x => x === 0, [ 0, 1, 1, 2, 3, 4, 1 ])).toEqual(0)
})
test('with curry', () => {
expect(findLast(x => x > 1)([ 1, 1, 1, 2, 3, 4, 1 ])).toEqual(4)
})
const obj1 = { x : 100 }
const obj2 = { x : 200 }
const a = [ 11, 10, 9, 'cow', obj1, 8, 7, 100, 200, 300, obj2, 4, 3, 2, 1, 0 ]
const even = function (x){
return x % 2 === 0
}
const gt100 = function (x){
return x > 100
}
const isStr = function (x){
return typeof x === 'string'
}
const xGt100 = function (o){
return o && o.x > 100
}
test('ramda 1', () => {
expect(findLast(even, a)).toEqual(0)
expect(findLast(gt100, a)).toEqual(300)
expect(findLast(isStr, a)).toEqual('cow')
expect(findLast(xGt100, a)).toEqual(obj2)
})
test('ramda 2', () => {
expect(findLast(even, [ 'zing' ])).toEqual(undefined)
})
test('ramda 3', () => {
expect(findLast(even, [ 2, 3, 5 ])).toEqual(2)
})
test('ramda 4', () => {
expect(findLast(even, [])).toEqual(undefined)
})
Typescript test
import {findLast} from 'rambda'
const list = [1, 2, 3]
describe('R.findLast', () => {
it('happy', () => {
const predicate = (x: number) => x > 2
const result = findLast(predicate, list)
result
})
it('curried', () => {
const predicate = (x: number) => x > 2
const result = findLast(predicate)(list)
result
})
})
findLastIndex
findLastIndex<T>(predicate: (x: T) => boolean, list: T[]): number
It returns the index of the last element of list
satisfying the predicate
function.
If there is no such element, then -1
is returned.
All Typescript definitions
findLastIndex<T>(predicate: (x: T) => boolean, list: T[]): number;
findLastIndex<T>(predicate: (x: T) => boolean): (list: T[]) => number;
R.findLastIndex source
export function findLastIndex(fn, list){
if (arguments.length === 1) return _list => findLastIndex(fn, _list)
let index = list.length
while (--index >= 0){
if (fn(list[ index ])){
return index
}
}
return -1
}
Tests
import { findLastIndex } from './findLastIndex.js'
test('happy', () => {
const result = findLastIndex(x => x > 1, [ 1, 1, 1, 2, 3, 4, 1 ])
expect(result).toEqual(5)
expect(findLastIndex(x => x === 0, [ 0, 1, 1, 2, 3, 4, 1 ])).toEqual(0)
})
test('with curry', () => {
expect(findLastIndex(x => x > 1)([ 1, 1, 1, 2, 3, 4, 1 ])).toEqual(5)
})
const obj1 = { x : 100 }
const obj2 = { x : 200 }
const a = [ 11, 10, 9, 'cow', obj1, 8, 7, 100, 200, 300, obj2, 4, 3, 2, 1, 0 ]
const even = function (x){
return x % 2 === 0
}
const gt100 = function (x){
return x > 100
}
const isStr = function (x){
return typeof x === 'string'
}
const xGt100 = function (o){
return o && o.x > 100
}
test('ramda 1', () => {
expect(findLastIndex(even, a)).toEqual(15)
expect(findLastIndex(gt100, a)).toEqual(9)
expect(findLastIndex(isStr, a)).toEqual(3)
expect(findLastIndex(xGt100, a)).toEqual(10)
})
test('ramda 2', () => {
expect(findLastIndex(even, [ 'zing' ])).toEqual(-1)
})
test('ramda 3', () => {
expect(findLastIndex(even, [ 2, 3, 5 ])).toEqual(0)
})
test('ramda 4', () => {
expect(findLastIndex(even, [])).toEqual(-1)
})
Typescript test
import {findLastIndex} from 'rambda'
const list = [1, 2, 3]
describe('R.findLastIndex', () => {
it('happy', () => {
const predicate = (x: number) => x > 2
const result = findLastIndex(predicate, list)
result
})
it('curried', () => {
const predicate = (x: number) => x > 2
const result = findLastIndex(predicate)(list)
result
})
})
flatten
flatten<T>(list: any[]): T[]
It deeply flattens an array.
All Typescript definitions
flatten<T>(list: any[]): T[];
R.flatten source
import { _isArray } from './_internals/_isArray.js'
export function flatten(list, input){
const willReturn = input === undefined ? [] : input
for (let i = 0; i < list.length; i++){
if (_isArray(list[ i ])){
flatten(list[ i ], willReturn)
} else {
willReturn.push(list[ i ])
}
}
return willReturn
}
Tests
import { flatten } from './flatten.js'
test('happy', () => {
expect(flatten([ 1, 2, 3, [ [ [ [ [ 4 ] ] ] ] ] ])).toEqual([ 1, 2, 3, 4 ])
expect(flatten([ 1, [ 2, [ [ 3 ] ] ], [ 4 ] ])).toEqual([ 1, 2, 3, 4 ])
expect(flatten([ 1, [ 2, [ [ [ 3 ] ] ] ], [ 4 ] ])).toEqual([ 1, 2, 3, 4 ])
expect(flatten([ 1, 2, [ 3, 4 ], 5, [ 6, [ 7, 8, [ 9, [ 10, 11 ], 12 ] ] ] ])).toEqual([ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 ])
})
test('readme example', () => {
const result = flatten([ 1, 2, [ 3, 30, [ 300 ] ], [ 4 ] ])
expect(result).toEqual([ 1, 2, 3, 30, 300, 4 ])
})
Typescript test
import {flatten} from 'rambda'
describe('flatten', () => {
it('happy', () => {
const result = flatten<number>([1, 2, [3, [4]]])
result
})
})
Rambda is fastest. Ramda is 95.26% slower and Lodash is 10.27% slower
const R = require('../../dist/rambda.js')
const list = [ 1, [ 2, [ 3, 4, 6 ] ] ]
const flatten = [
{
label : 'Rambda',
fn : () => {
R.flatten(list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.flatten(list)
},
},
{
label : 'Lodash',
fn : () => {
_.flatten(list)
},
},
]
flip
It returns function which calls fn
with exchanged first and second argument.
forEach
forEach<T>(fn: Iterator<T, void>, list: T[]): T[]
It applies iterable
function over all members of list
and returns list
.
All Typescript definitions
forEach<T>(fn: Iterator<T, void>, list: T[]): T[];
forEach<T>(fn: Iterator<T, void>): (list: T[]) => T[];
forEach<T>(fn: ObjectIterator<T, void>, list: Dictionary<T>): Dictionary<T>;
forEach<T, U>(fn: ObjectIterator<T, void>): (list: Dictionary<T>) => Dictionary<T>;
R.forEach source
import { _isArray } from './_internals/_isArray.js'
import { _keys } from './_internals/_keys.js'
export function forEach(fn, list){
if (arguments.length === 1) return _list => forEach(fn, _list)
if (list === undefined){
return
}
if (_isArray(list)){
let index = 0
const len = list.length
while (index < len){
fn(list[ index ])
index++
}
} else {
let index = 0
const keys = _keys(list)
const len = keys.length
while (index < len){
const key = keys[ index ]
fn(
list[ key ], key, list
)
index++
}
}
return list
}
Tests
import { forEach } from './forEach.js'
import { type } from './type.js'
test('happy', () => {
const sideEffect = {}
forEach(x => sideEffect[ `foo${ x }` ] = x + 10)([ 1, 2 ])
expect(sideEffect).toEqual({
foo1 : 11,
foo2 : 12,
})
})
test('iterate over object', () => {
const obj = {
a : 1,
b : [ 1, 2 ],
c : { d : 7 },
f : 'foo',
}
const result = {}
const returned = forEach((
val, prop, inputObj
) => {
expect(type(inputObj)).toBe('Object')
result[ prop ] = `${ prop }-${ type(val) }`
})(obj)
const expected = {
a : 'a-Number',
b : 'b-Array',
c : 'c-Object',
f : 'f-String',
}
expect(result).toEqual(expected)
expect(returned).toEqual(obj)
})
test('with empty list', () => {
const list = []
const result = forEach(x => x * x)(list)
expect(result).toEqual(list)
})
test('with wrong input', () => {
const list = undefined
const result = forEach(x => x * x)(list)
expect(result).toBeUndefined()
})
test('returns the input', () => {
const list = [ 1, 2, 3 ]
const result = forEach(x => x * x)(list)
expect(result).toEqual(list)
})
Typescript test
import {forEach} from 'rambda'
const list = [1, 2, 3]
const obj = {a: 1, b: 2}
describe('R.forEach with arrays', () => {
it('happy', () => {
const result = forEach(a => {
a
}, list)
result
})
it('curried require an explicit typing', () => {
const result = forEach<number>(a => {
a
})(list)
result
})
})
describe('R.forEach with objects', () => {
it('happy', () => {
const result = forEach((a, b, c) => {
a
b
c
return `${a}`
}, obj)
result
})
it('curried require an input typing and a dummy third typing', () => {
const result = forEach<number, any>((a, b, c) => {
a
b
c
})(obj)
result
})
it('iterator without property', () => {
const result = forEach(a => {
a
}, obj)
result
})
})
fromPairs
It transforms a listOfPairs
to an object.
groupBy
It splits list
according to a provided groupFn
function and returns an object.
groupWith
It returns separated version of list or string input
, where separation is done with equality compareFn
function.
has
has<T>(prop: string, obj: T): boolean
It returns true
if obj
has property prop
.
All Typescript definitions
has<T>(prop: string, obj: T): boolean;
has(prop: string): <T>(obj: T) => boolean;
R.has source
export function has(prop, obj){
if (arguments.length === 1) return _obj => has(prop, _obj)
if (!obj) return false
return obj.hasOwnProperty(prop)
}
Tests
import {has} from './has.js'
test('happy', () => {
expect(has('a')({a: 1})).toBeTrue()
expect(has('b', {a: 1})).toBeFalse()
})
test('with non-object', () => {
expect(has('a', undefined)).toBeFalse()
expect(has('a', null)).toBeFalse()
expect(has('a', true)).toBeFalse()
expect(has('a', '')).toBeFalse()
expect(has('a', /a/)).toBeFalse()
})
Typescript test
import {has} from 'rambda'
describe('R.has', () => {
it('happy', () => {
const result = has('foo', {a: 1})
const curriedResult = has('bar')({a: 1})
result
curriedResult
})
})
hasPath
hasPath<T>(
path: string | string[],
input: object
): boolean
It will return true, if input
object has truthy path
(calculated with R.path
).
All Typescript definitions
hasPath<T>(
path: string | string[],
input: object
): boolean;
hasPath<T>(
path: string | string[]
): (input: object) => boolean;
R.hasPath source
import { path } from './path.js'
export function hasPath(pathInput, obj){
if (arguments.length === 1){
return objHolder => hasPath(pathInput, objHolder)
}
return path(pathInput, obj) !== undefined
}
Tests
import { hasPath } from './hasPath.js'
test('when true', () => {
const path = 'a.b'
const obj = { a : { b : [] } }
const result = hasPath(path)(obj)
const expectedResult = true
expect(result).toEqual(expectedResult)
})
test('when false', () => {
const path = 'a.b'
const obj = {}
const result = hasPath(path, obj)
const expectedResult = false
expect(result).toEqual(expectedResult)
})
Typescript test
import {hasPath} from 'rambda'
describe('R.hasPath', () => {
it('string path', () => {
const obj = {a: {b: 1}}
const result = hasPath('a.b', obj)
const curriedResult = hasPath('a.c')(obj)
result
curriedResult
})
it('array path', () => {
const obj = {a: {b: 1}}
const result = hasPath(['a', 'b'], obj)
const curriedResult = hasPath(['a', 'c'])(obj)
result
curriedResult
})
})
head
head(input: string): string
It returns the first element of list or string input
.
All Typescript definitions
head(input: string): string;
head(emptyList: []): undefined;
head<T>(input: T[]): T | undefined;
R.head source
export function head(listOrString){
if (typeof listOrString === 'string') return listOrString[ 0 ] || ''
return listOrString[ 0 ]
}
Tests
import { head } from './head.js'
test('head', () => {
expect(head([ 'fi', 'fo', 'fum' ])).toEqual('fi')
expect(head([])).toEqual(undefined)
expect(head('foo')).toEqual('f')
expect(head('')).toEqual('')
})
Typescript test
import {head} from 'rambda'
describe('R.head', () => {
it('string', () => {
const result = head('foo')
result
})
it('array', () => {
const result = head([1, 2, 3])
result
})
it('empty array - case 1', () => {
const result = head([])
result
})
it('empty array - case 2', () => {
const list = ['foo', 'bar'].filter(x => x.startsWith('a'))
const result = head(list)
result
})
})
identical
It returns true
if its arguments a
and b
are identical.
Otherwise, it returns false
.
identity
identity<T>(input: T): T
It just passes back the supplied input
argument.
All Typescript definitions
identity<T>(input: T): T;
R.identity source
export function identity(x){
return x
}
Tests
import {identity} from './identity.js'
test('happy', () => {
expect(identity(7)).toEqual(7)
expect(identity(true)).toBeTrue()
expect(identity({a: 1})).toEqual({a: 1})
})
Typescript test
import {identity} from 'rambda'
describe('R.identity', () => {
it('happy', () => {
const result = identity(4)
result
})
})
ifElse
ifElse<TArgs extends any[], TOnTrueResult, TOnFalseResult>(fn: (...args: TArgs) => boolean, onTrue: (...args: TArgs) => TOnTrueResult, onFalse: (...args: TArgs) => TOnFalseResult): (...args: TArgs) => TOnTrueResult | TOnFalseResult
It expects condition
, onTrue
and onFalse
functions as inputs and it returns a new function with example name of fn
.
When fn`` is called with
inputargument, it will return either
onTrue(input)or
onFalse(input)depending on
condition(input)` evaluation.
All Typescript definitions
ifElse<TArgs extends any[], TOnTrueResult, TOnFalseResult>(fn: (...args: TArgs) => boolean, onTrue: (...args: TArgs) => TOnTrueResult, onFalse: (...args: TArgs) => TOnFalseResult): (...args: TArgs) => TOnTrueResult | TOnFalseResult;
R.ifElse source
import { curry } from './curry.js'
function ifElseFn(
condition, onTrue, onFalse
){
return (...input) => {
const conditionResult =
typeof condition === 'boolean' ? condition : condition(...input)
if (conditionResult === true){
return onTrue(...input)
}
return onFalse(...input)
}
}
export const ifElse = curry(ifElseFn)
Tests
import {always} from './always.js'
import {has} from './has.js'
import {identity} from './identity.js'
import {ifElse} from './ifElse.js'
import {prop} from './prop.js'
const condition = has('foo')
const v = function (a) {
return typeof a === 'number'
}
const t = function (a) {
return a + 1
}
const ifFn = x => prop('foo', x).length
const elseFn = () => false
test('happy', () => {
const fn = ifElse(condition, ifFn)(elseFn)
expect(fn({foo: 'bar'})).toEqual(3)
expect(fn({fo: 'bar'})).toBeFalse()
})
test('ramda spec', () => {
const ifIsNumber = ifElse(v)
expect(ifIsNumber(t, identity)(15)).toEqual(16)
expect(ifIsNumber(t, identity)('hello')).toEqual('hello')
})
test('pass all arguments', () => {
const identity = function (a) {
return a
}
const v = function () {
return true
}
const onTrue = function (a, b) {
expect(a).toEqual(123)
expect(b).toEqual('abc')
}
ifElse(v, onTrue, identity)(123, 'abc')
})
test('accept constant as condition', () => {
const fn = ifElse(true)(always(true))(always(false))
expect(fn()).toBeTrue()
})
test('accept constant as condition - case 2', () => {
const fn = ifElse(false, always(true), always(false))
expect(fn()).toBeFalse()
})
test('curry 1', () => {
const fn = ifElse(condition, ifFn)(elseFn)
expect(fn({foo: 'bar'})).toEqual(3)
expect(fn({fo: 'bar'})).toBeFalse()
})
test('curry 2', () => {
const fn = ifElse(condition)(ifFn)(elseFn)
expect(fn({foo: 'bar'})).toEqual(3)
expect(fn({fo: 'bar'})).toBeFalse()
})
test('simple arity of 1', () => {
const condition = x => x > 5
const onTrue = x => x + 1
const onFalse = x => x + 10
const result = ifElse(condition, onTrue, onFalse)(1)
expect(result).toBe(11)
})
test('simple arity of 2', () => {
const condition = (x, y) => x + y > 5
const onTrue = (x, y) => x + y + 1
const onFalse = (x, y) => x + y + 10
const result = ifElse(condition, onTrue, onFalse)(1, 10)
expect(result).toBe(12)
})
Typescript test
import {ifElse} from 'rambda'
describe('R.ifElse', () => {
it('happy', () => {
const condition = (x: number) => x > 5
const onTrue = (x: number) => `foo${x}`
const onFalse = (x: number) => `bar${x}`
const fn = ifElse(condition, onTrue, onFalse)
fn
const result = fn(3)
result
})
it('arity of 2', () => {
const condition = (x: number, y: string) => x + y.length > 5
const onTrue = (x: number, y: string) => `foo${x}-${y}`
const onFalse = (x: number, y: string) => `bar${x}-${y}`
const fn = ifElse(condition, onTrue, onFalse)
fn
const result = fn(3, 'hello')
result
})
})
Rambda is faster than Ramda with 58.56%
const R = require('../../dist/rambda.js')
const condition = R.has('foo')
const v = function (a){
return typeof a === 'number'
}
const t = function (a){
return a + 1
}
const ifFn = x => R.prop('foo', x).length
const elseFn = () => false
const ifElse = [
{
label : 'Rambda',
fn : () => {
const fn = R.ifElse(condition, ifFn)(elseFn)
fn({ foo : 'bar' })
fn({ fo : 'bar' })
const ifIsNumber = R.ifElse(v)
ifIsNumber(t, R.identity)(15)
ifIsNumber(t, R.identity)('hello')
},
},
{
label : 'Ramda',
fn : () => {
const fn = Ramda.ifElse(condition, ifFn)(elseFn)
fn({ foo : 'bar' })
fn({ fo : 'bar' })
const ifIsNumber = Ramda.ifElse(v)
ifIsNumber(t, R.identity)(15)
ifIsNumber(t, R.identity)('hello')
},
},
]
inc
It increments a number.
includes
includes(valueToFind: string, input: string[] | string): boolean
If input
is string, then this method work as native String.includes
.
If input
is array, then R.equals
is used to define if valueToFind
belongs to the list.
All Typescript definitions
includes(valueToFind: string, input: string[] | string): boolean;
includes(valueToFind: string): (input: string[] | string) => boolean;
includes<T>(valueToFind: T, input: T[]): boolean;
includes<T>(valueToFind: T): (input: T[]) => boolean;
R.includes source
import { _isArray } from './_internals/_isArray.js'
import { _indexOf } from './equals.js'
export function includes(valueToFind, iterable){
if (arguments.length === 1)
return _iterable => includes(valueToFind, _iterable)
if (typeof iterable === 'string'){
return iterable.includes(valueToFind)
}
if (!iterable){
throw new TypeError(`Cannot read property \'indexOf\' of ${ iterable }`)
}
if (!_isArray(iterable)) return false
return _indexOf(valueToFind, iterable) > -1
}
Tests
import { includes as includesRamda } from 'ramda'
import { includes } from './includes.js'
test('with string as iterable', () => {
const str = 'foo bar'
expect(includes('bar')(str)).toBeTrue()
expect(includesRamda('bar')(str)).toBeTrue()
expect(includes('never', str)).toBeFalse()
expect(includesRamda('never', str)).toBeFalse()
})
test('with array as iterable', () => {
const arr = [ 1, 2, 3 ]
expect(includes(2)(arr)).toBeTrue()
expect(includesRamda(2)(arr)).toBeTrue()
expect(includes(4, arr)).toBeFalse()
expect(includesRamda(4, arr)).toBeFalse()
})
test('with list of objects as iterable', () => {
const arr = [ { a : 1 }, { b : 2 }, { c : 3 } ]
expect(includes({ c : 3 }, arr)).toBeTrue()
expect(includesRamda({ c : 3 }, arr)).toBeTrue()
})
test('with NaN', () => {
const result = includes(NaN, [ NaN ])
const ramdaResult = includesRamda(NaN, [ NaN ])
expect(result).toBeTrue()
expect(ramdaResult).toBeTrue()
})
test('with wrong input that does not throw', () => {
const result = includes(1, /foo/g)
const ramdaResult = includesRamda(1, /foo/g)
expect(result).toBeFalse()
expect(ramdaResult).toBeFalse()
})
test('throws on wrong input - match ramda behaviour', () => {
expect(() => includes(2, null)).toThrowWithMessage(TypeError,
'Cannot read property \'indexOf\' of null')
expect(() => includesRamda(2, null)).toThrowWithMessage(TypeError,
'Cannot read properties of null (reading \'indexOf\')')
expect(() => includes(2, undefined)).toThrowWithMessage(TypeError,
'Cannot read property \'indexOf\' of undefined')
expect(() => includesRamda(2, undefined)).toThrowWithMessage(TypeError,
'Cannot read properties of undefined (reading \'indexOf\')')
})
Typescript test
import {includes} from 'rambda'
const list = [{a: {b: '1'}}, {a: {c: '2'}}, {a: {b: '3'}}]
describe('R.includes', () => {
it('happy', () => {
const result = includes({a: {b: '1'}}, list)
result
})
it('with string', () => {
const result = includes('oo', 'foo')
const curriedResult = includes('oo')('foo')
result
curriedResult
})
})
Rambda is faster than Ramda with 84.68%
const R = require('../../dist/rambda.js')
const {
uniqListOfStrings,
uniqListOfBooleans,
uniqListOfObjects,
uniqListOfLists,
listOfVariousTypes,
rangeOfNumbers,
} = require('./_utils.js')
const limit = 100
const additionalModes = listOfVariousTypes.map(unknownType => [
unknownType,
uniqListOfLists(limit),
])
const modes = [
[ 99, rangeOfNumbers(limit) ],
[ 200, rangeOfNumbers(limit) ],
...additionalModes,
[ 'zeppelin', uniqListOfStrings(limit) ],
[ null, uniqListOfBooleans(limit) ],
[ {
foo : true,
bar : true,
}, uniqListOfObjects(limit) ],
[ 1, uniqListOfLists(limit) ],
[ [ 1 ], uniqListOfLists(limit) ],
]
function applyBenchmark(fn, input){
return fn(input[ 0 ], input[ 1 ])
}
const tests = [
{
label : 'Rambda',
fn : R.includes,
},
{
label : 'Ramda',
fn : Ramda.includes,
},
]
tests,
modes,
applyBenchmark,
}
indexBy
It generates object with properties provided by condition
and values provided by list
array.
If condition
is a function, then all list members are passed through it.
If condition
is a string, then all list members are passed through R.path(condition)
.
indexOf
It returns the index of the first element of list
equals to valueToFind
.
If there is no such element, it returns -1
.
init
init<T extends unknown[]>(input: T): T extends readonly [...infer U, any] ? U : [...T]
It returns all but the last element of list or string input
.
All Typescript definitions
init<T extends unknown[]>(input: T): T extends readonly [...infer U, any] ? U : [...T];
init(input: string): string;
R.init source
import baseSlice from './_internals/baseSlice.js'
export function init(listOrString){
if (typeof listOrString === 'string') return listOrString.slice(0, -1)
return listOrString.length ?
baseSlice(
listOrString, 0, -1
) :
[]
}
Tests
import { init } from './init.js'
test('with array', () => {
expect(init([ 1, 2, 3 ])).toEqual([ 1, 2 ])
expect(init([ 1, 2 ])).toEqual([ 1 ])
expect(init([ 1 ])).toEqual([])
expect(init([])).toEqual([])
expect(init([])).toEqual([])
expect(init([ 1 ])).toEqual([])
})
test('with string', () => {
expect(init('foo')).toEqual('fo')
expect(init('f')).toEqual('')
expect(init('')).toEqual('')
})
Typescript test
import {init} from 'rambda'
describe('R.init', () => {
it('with string', () => {
const result = init('foo')
result
})
it('with list - one type', () => {
const result = init([1, 2, 3])
result
})
it('with list - mixed types', () => {
const result = init([1, 2, 3, 'foo', 'bar'])
result
})
})
Rambda is fastest. Ramda is 92.24% slower and Lodash is 13.3% slower
const R = require('../../dist/rambda.js')
const list = [ 1, 2, 3, 4 ]
const init = [
{
label : 'Rambda',
fn : () => {
R.init(list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.init(list)
},
},
{
label : 'Lodash',
fn : () => {
_.initial(list)
},
},
]
intersection
It loops throw listA
and listB
and returns the intersection of the two according to R.equals
.
intersperse
It adds a separator
between members of list
.
is
It returns true
if x
is instance of targetPrototype
.
isEmpty
isEmpty<T>(x: T): boolean
It returns true
if x
is empty
.
All Typescript definitions
isEmpty<T>(x: T): boolean;
R.isEmpty source
import { type } from './type.js'
export function isEmpty(input){
const inputType = type(input)
if ([ 'Undefined', 'NaN', 'Number', 'Null' ].includes(inputType))
return false
if (!input) return true
if (inputType === 'Object'){
return Object.keys(input).length === 0
}
if (inputType === 'Array'){
return input.length === 0
}
return false
}
Tests
import {isEmpty} from './isEmpty.js'
test('happy', () => {
expect(isEmpty(undefined)).toBeFalse()
expect(isEmpty('')).toBeTrue()
expect(isEmpty(null)).toBeFalse()
expect(isEmpty(' ')).toBeFalse()
expect(isEmpty(new RegExp(''))).toBeFalse()
expect(isEmpty([])).toBeTrue()
expect(isEmpty([[]])).toBeFalse()
expect(isEmpty({})).toBeTrue()
expect(isEmpty({x: 0})).toBeFalse()
expect(isEmpty(0)).toBeFalse()
expect(isEmpty(NaN)).toBeFalse()
expect(isEmpty([''])).toBeFalse()
})
Typescript test
import {isEmpty} from 'rambda'
describe('R.isEmpty', () => {
it('happy', () => {
const result = isEmpty('foo')
result
})
})
Rambda is fastest. Ramda is 97.14% slower and Lodash is 54.99% slower
const R = require('../../dist/rambda.js')
const isEmpty = [
{
label : 'Rambda',
fn : () => {
R.isEmpty(undefined)
R.isEmpty('')
R.isEmpty(null)
R.isEmpty(' ')
R.isEmpty(new RegExp(''))
R.isEmpty([])
R.isEmpty([ [] ])
R.isEmpty({})
R.isEmpty({ x : 0 })
R.isEmpty(0)
R.isEmpty(NaN)
R.isEmpty([ '' ])
},
},
{
label : 'Ramda',
fn : () => {
Ramda.isEmpty(undefined)
Ramda.isEmpty('')
Ramda.isEmpty(null)
Ramda.isEmpty(' ')
Ramda.isEmpty(new RegExp(''))
Ramda.isEmpty([])
Ramda.isEmpty([ [] ])
Ramda.isEmpty({})
Ramda.isEmpty({ x : 0 })
Ramda.isEmpty(0)
Ramda.isEmpty(NaN)
Ramda.isEmpty([ '' ])
},
},
{
label : 'Lodash',
fn : () => {
_.isEmpty(undefined)
_.isEmpty('')
_.isEmpty(null)
_.isEmpty(' ')
_.isEmpty(new RegExp(''))
_.isEmpty([])
_.isEmpty([ [] ])
_.isEmpty({})
_.isEmpty({ x : 0 })
_.isEmpty(0)
_.isEmpty(NaN)
_.isEmpty([ '' ])
},
},
]
isNil
isNil(x: any): x is null | undefined
It returns true
if x
is either null
or undefined
.
All Typescript definitions
isNil(x: any): x is null | undefined;
R.isNil source
export function isNil(x){
return x === undefined || x === null
}
Tests
import { isNil } from './isNil.js'
test('happy', () => {
expect(isNil(null)).toBeTrue()
expect(isNil(undefined)).toBeTrue()
expect(isNil([])).toBeFalse()
})
join
join<T>(glue: string, list: T[]): string
It returns a string of all list
instances joined with a glue
.
All Typescript definitions
join<T>(glue: string, list: T[]): string;
join<T>(glue: string): (list: T[]) => string;
R.join source
export function join(glue, list){
if (arguments.length === 1) return _list => join(glue, _list)
return list.join(glue)
}
Tests
import { join } from './join.js'
test('curry', () => {
expect(join('|')([ 'foo', 'bar', 'baz' ])).toEqual('foo|bar|baz')
expect(join('|', [ 1, 2, 3 ])).toEqual('1|2|3')
const spacer = join(' ')
expect(spacer([ 'a', 2, 3.4 ])).toEqual('a 2 3.4')
})
Typescript test
import {join} from 'rambda'
describe('R.join', () => {
it('happy', () => {
const result = join('|', [1, 2, 3])
result
})
})
juxt
juxt<A extends any[], R1>(fns: [(...a: A) => R1]): (...a: A) => [R1]
It applies list of function to a list of inputs.
All Typescript definitions
juxt<A extends any[], R1>(fns: [(...a: A) => R1]): (...a: A) => [R1];
juxt<A extends any[], R1, R2>(fns: [(...a: A) => R1, (...a: A) => R2]): (...a: A) => [R1, R2];
juxt<A extends any[], R1, R2, R3>(fns: [(...a: A) => R1, (...a: A) => R2, (...a: A) => R3]): (...a: A) => [R1, R2, R3];
juxt<A extends any[], R1, R2, R3, R4>(fns: [(...a: A) => R1, (...a: A) => R2, (...a: A) => R3, (...a: A) => R4]): (...a: A) => [R1, R2, R3, R4];
juxt<A extends any[], R1, R2, R3, R4, R5>(fns: [(...a: A) => R1, (...a: A) => R2, (...a: A) => R3, (...a: A) => R4, (...a: A) => R5]): (...a: A) => [R1, R2, R3, R4, R5];
juxt<A extends any[], U>(fns: Array<(...args: A) => U>): (...args: A) => U[];
R.juxt source
export function juxt(listOfFunctions){
return (...args) => listOfFunctions.map(fn => fn(...args))
}
Tests
import {juxt} from './juxt.js'
test('happy', () => {
const fn = juxt([Math.min, Math.max, Math.min])
const result = fn(3, 4, 9, -3)
expect(result).toEqual([-3, 9, -3])
})
Typescript test
import {juxt} from 'rambda'
describe('R.juxt', () => {
it('happy', () => {
const fn = juxt([Math.min, Math.max])
const result = fn(3, 4, 9, -3)
result
})
})
keys
keys<T extends object>(x: T): (keyof T)[]
It applies Object.keys
over x
and returns its keys.
All Typescript definitions
keys<T extends object>(x: T): (keyof T)[];
keys<T>(x: T): string[];
R.keys source
export function keys(x){
return Object.keys(x)
}
Tests
import { keys } from './keys.js'
test('happy', () => {
expect(keys({ a : 1 })).toEqual([ 'a' ])
})
Typescript test
import {keys} from 'rambda'
const obj = {a: 1, b: 2}
describe('R.keys', () => {
it('happy', () => {
const result = keys(obj)
result
})
})
last
last(str: string): string
It returns the last element of input
, as the input
can be either a string or an array.
All Typescript definitions
last(str: string): string;
last(emptyList: []): undefined;
last<T extends any>(list: T[]): T | undefined;
R.last source
export function last(listOrString){
if (typeof listOrString === 'string'){
return listOrString[ listOrString.length - 1 ] || ''
}
return listOrString[ listOrString.length - 1 ]
}
Tests
import { last } from './last.js'
test('with list', () => {
expect(last([ 1, 2, 3 ])).toBe(3)
expect(last([])).toBeUndefined()
})
test('with string', () => {
expect(last('abc')).toEqual('c')
expect(last('')).toEqual('')
})
Typescript test
import {last} from 'rambda'
describe('R.last', () => {
it('string', () => {
const result = last('foo')
result
})
it('array', () => {
const result = last([1, 2, 3])
result
})
it('empty array - case 1', () => {
const result = last([])
result
})
it('empty array - case 2', () => {
const list = ['foo', 'bar'].filter(x => x.startsWith('a'))
const result = last(list)
result
})
})
Rambda is fastest. Ramda is 93.43% slower and Lodash is 5.28% slower
const R = require('../../dist/rambda.js')
const list = [ 1, 2, 3, 4 ]
const last = [
{
label : 'Rambda',
fn : () => {
R.last(list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.last(list)
},
},
{
label : 'Lodash',
fn : () => {
_.last(list)
},
},
]
lastIndexOf
lastIndexOf<T>(target: T, list: T[]): number
It returns the last index of target
in list
array.
R.equals
is used to determine equality between target
and members of list
.
If there is no such index, then -1
is returned.
All Typescript definitions
lastIndexOf<T>(target: T, list: T[]): number;
lastIndexOf<T>(target: T): (list: T[]) => number;
R.lastIndexOf source
import { _lastIndexOf } from './equals.js'
export function lastIndexOf(valueToFind, list){
if (arguments.length === 1){
return _list => _lastIndexOf(valueToFind, _list)
}
return _lastIndexOf(valueToFind, list)
}
Tests
import { lastIndexOf as lastIndexOfRamda } from 'ramda'
import { compareCombinations } from './_internals/testUtils.js'
import { possibleIterables, possibleTargets } from './indexOf.spec.js'
import { lastIndexOf } from './lastIndexOf.js'
test('with NaN', () => {
expect(lastIndexOf(NaN, [ NaN ])).toEqual(0)
})
test('will throw with bad input', () => {
expect(lastIndexOfRamda([], true)).toEqual(-1)
expect(() => indexOf([], true)).toThrow()
})
test('without list of objects - no R.equals', () => {
expect(lastIndexOf(3, [ 1, 2, 3, 4 ])).toEqual(2)
expect(lastIndexOf(10)([ 1, 2, 3, 4 ])).toEqual(-1)
})
test('list of objects uses R.equals', () => {
const listOfObjects = [ { a : 1 }, { b : 2 }, { c : 3 } ]
expect(lastIndexOf({ c : 4 }, listOfObjects)).toBe(-1)
expect(lastIndexOf({ c : 3 }, listOfObjects)).toBe(2)
})
test('list of arrays uses R.equals', () => {
const listOfLists = [ [ 1 ], [ 2, 3 ], [ 2, 3, 4 ], [ 2, 3 ], [ 1 ], [] ]
expect(lastIndexOf([], listOfLists)).toBe(5)
expect(lastIndexOf([ 1 ], listOfLists)).toBe(4)
expect(lastIndexOf([ 2, 3, 4 ], listOfLists)).toBe(2)
expect(lastIndexOf([ 2, 3, 5 ], listOfLists)).toBe(-1)
})
test('with string as iterable', () => {
expect(() => lastIndexOf('a', 'abc')).toThrowWithMessage(Error,
'Cannot read property \'indexOf\' of abc')
expect(lastIndexOfRamda('a', 'abc')).toBe(0)
})
describe('brute force', () => {
compareCombinations({
fn : lastIndexOf,
fnRamda : lastIndexOfRamda,
firstInput : possibleTargets,
secondInput : possibleIterables,
callback : errorsCounters => {
expect(errorsCounters).toMatchInlineSnapshot(`
Object {
"ERRORS_MESSAGE_MISMATCH": 0,
"ERRORS_TYPE_MISMATCH": 34,
"RESULTS_MISMATCH": 0,
"SHOULD_NOT_THROW": 51,
"SHOULD_THROW": 0,
"TOTAL_TESTS": 170,
}
`)
},
})
})
Typescript test
import {lastIndexOf} from 'rambda'
const list = [1, 2, 3]
describe('R.lastIndexOf', () => {
it('happy', () => {
const result = lastIndexOf(2, list)
result
})
it('curried', () => {
const result = lastIndexOf(2)(list)
result
})
})
Rambda is faster than Ramda with 85.19%
const R = require('../../dist/rambda.js')
const isEven = n => n % 2 === 0
const arr = [ 1, 3, 5, 7, 9, 11 ]
const lastIndexOf = [
{
label : 'Rambda',
fn : () => {
R.lastIndexOf(1, [ 1, 2, 3, 1, 2 ])
R.lastIndexOf(1)([ 1, 2, 3, 1, 2 ])
},
},
{
label : 'Ramda',
fn : () => {
Ramda.lastIndexOf(1, [ 1, 2, 3, 1, 2 ])
Ramda.lastIndexOf(1)([ 1, 2, 3, 1, 2 ])
},
},
]
length
length<T>(input: T[]): number
It returns the length
property of list or string input
.
All Typescript definitions
length<T>(input: T[]): number;
R.length source
import { _isArray } from './_internals/_isArray.js'
export function length(x){
if (_isArray(x)) return x.length
if (typeof x === 'string') return x.length
return NaN
}
Tests
import { length as lengthRamda } from 'ramda'
import { length } from './length.js'
test('happy', () => {
expect(length('foo')).toEqual(3)
expect(length([ 1, 2, 3 ])).toEqual(3)
expect(length([])).toEqual(0)
})
test('with empty string', () => {
expect(length('')).toEqual(0)
})
test('with bad input returns NaN', () => {
expect(length(0)).toBeNaN()
expect(length({})).toBeNaN()
expect(length(null)).toBeNaN()
expect(length(undefined)).toBeNaN()
})
test('with length as property', () => {
const input1 = { length : '123' }
const input2 = { length : null }
const input3 = { length : '' }
expect(length(input1)).toBeNaN()
expect(lengthRamda(input1)).toBeNaN()
expect(length(input2)).toBeNaN()
expect(lengthRamda(input2)).toBeNaN()
expect(length(input3)).toBeNaN()
expect(lengthRamda(input3)).toBeNaN()
})
lens
lens<T, U, V>(getter: (s: T) => U, setter: (a: U, s: T) => V): Lens
It returns a lens
for the given getter
and setter
functions.
The getter
gets the value of the focus; the setter
sets the value of the focus.
The setter should not mutate the data structure.
All Typescript definitions
lens<T, U, V>(getter: (s: T) => U, setter: (a: U, s: T) => V): Lens;
R.lens source
export function lens(getter, setter){
return function (functor){
return function (target){
return functor(getter(target)).map(focus => setter(focus, target))
}
}
}
Typescript test
import {lens, assoc} from 'rambda'
interface Input {
foo: string
}
describe('R.lens', () => {
it('happy', () => {
const fn = lens<Input, string, string>((x: Input) => {
x.foo
return x.foo
}, assoc('name'))
fn
})
})
lensIndex
lensIndex(index: number): Lens
It returns a lens that focuses on specified index
.
All Typescript definitions
lensIndex(index: number): Lens;
R.lensIndex source
import { lens } from './lens.js'
import { nth } from './nth.js'
import { update } from './update.js'
export function lensIndex(index){
return lens(nth(index), update(index))
}
Tests
import { compose } from './compose.js'
import { keys } from './keys.js'
import { lensIndex } from './lensIndex.js'
import { over } from './over.js'
import { set } from './set.js'
import { view } from './view.js'
const testList = [ { a : 1 }, { b : 2 }, { c : 3 } ]
test('focuses list element at the specified index', () => {
expect(view(lensIndex(0), testList)).toEqual({ a : 1 })
})
test('returns undefined if the specified index does not exist', () => {
expect(view(lensIndex(10), testList)).toEqual(undefined)
})
test('sets the list value at the specified index', () => {
expect(set(
lensIndex(0), 0, testList
)).toEqual([ 0, { b : 2 }, { c : 3 } ])
})
test('applies function to the value at the specified list index', () => {
expect(over(
lensIndex(2), keys, testList
)).toEqual([ { a : 1 }, { b : 2 }, [ 'c' ] ])
})
test('can be composed', () => {
const nestedList = [ 0, [ 10, 11, 12 ], 1, 2 ]
const composedLens = compose(lensIndex(1), lensIndex(0))
expect(view(composedLens, nestedList)).toEqual(10)
})
test('set s (get s) === s', () => {
expect(set(
lensIndex(0), view(lensIndex(0), testList), testList
)).toEqual(testList)
})
test('get (set s v) === v', () => {
expect(view(lensIndex(0), set(
lensIndex(0), 0, testList
))).toEqual(0)
})
test('get (set(set s v1) v2) === v2', () => {
expect(view(lensIndex(0),
set(
lensIndex(0), 11, set(
lensIndex(0), 10, testList
)
))).toEqual(11)
})
Typescript test
import {view, lensIndex} from 'rambda'
interface Input {
a: number
}
const testList: Input[] = [{a: 1}, {a: 2}, {a: 3}]
describe('R.lensIndex', () => {
it('happy', () => {
const result = view<Input[], Input>(lensIndex(0), testList)
result
result.a
})
})
lensPath
lensPath(path: RamdaPath): Lens
It returns a lens that focuses on specified path
.
All Typescript definitions
lensPath(path: RamdaPath): Lens;
lensPath(path: string): Lens;
R.lensPath source
import { assocPath } from './assocPath.js'
import { lens } from './lens.js'
import { path } from './path.js'
export function lensPath(key){
return lens(path(key), assocPath(key))
}
Tests
import { compose } from './compose.js'
import { identity } from './identity.js'
import { inc } from './inc.js'
import { lensPath } from './lensPath.js'
import { lensProp } from './lensProp.js'
import { over } from './over.js'
import { set } from './set.js'
import { view } from './view.js'
const testObj = {
a : [ { b : 1 }, { b : 2 } ],
d : 3,
}
test('view', () => {
expect(view(lensPath('d'), testObj)).toEqual(3)
expect(view(lensPath('a.0.b'), testObj)).toEqual(1)
expect(view(lensPath(''), testObj)).toEqual(undefined)
})
test('set', () => {
expect(set(
lensProp('d'), 0, testObj
)).toEqual({
a : [ { b : 1 }, { b : 2 } ],
d : 0,
})
expect(set(
lensPath('a.0.b'), 0, testObj
)).toEqual({
a : [ { b : 0 }, { b : 2 } ],
d : 3,
})
expect(set(
lensPath('a.0.X'), 0, testObj
)).toEqual({
a : [
{
b : 1,
X : 0,
},
{ b : 2 },
],
d : 3,
})
expect(set(
lensPath([]), 0, testObj
)).toEqual(0)
})
test('over', () => {
expect(over(
lensPath('d'), inc, testObj
)).toEqual({
a : [ { b : 1 }, { b : 2 } ],
d : 4,
})
expect(over(
lensPath('a.1.b'), inc, testObj
)).toEqual({
a : [ { b : 1 }, { b : 3 } ],
d : 3,
})
expect(over(
lensProp('X'), identity, testObj
)).toEqual({
a : [ { b : 1 }, { b : 2 } ],
d : 3,
X : undefined,
})
expect(over(
lensPath('a.0.X'), identity, testObj
)).toEqual({
a : [
{
b : 1,
X : undefined,
},
{ b : 2 },
],
d : 3,
})
})
test('compose', () => {
const composedLens = compose(lensPath('a'), lensPath('1.b'))
expect(view(composedLens, testObj)).toEqual(2)
})
test('set s (get s) === s', () => {
expect(set(
lensPath([ 'd' ]), view(lensPath([ 'd' ]), testObj), testObj
)).toEqual(testObj)
expect(set(
lensPath([ 'a', 0, 'b' ]),
view(lensPath([ 'a', 0, 'b' ]), testObj),
testObj
)).toEqual(testObj)
})
test('get (set s v) === v', () => {
expect(view(lensPath([ 'd' ]), set(
lensPath([ 'd' ]), 0, testObj
))).toEqual(0)
expect(view(lensPath([ 'a', 0, 'b' ]), set(
lensPath([ 'a', 0, 'b' ]), 0, testObj
))).toEqual(0)
})
test('get (set(set s v1) v2) === v2', () => {
const p = [ 'd' ]
const q = [ 'a', 0, 'b' ]
expect(view(lensPath(p), set(
lensPath(p), 11, set(
lensPath(p), 10, testObj
)
))).toEqual(11)
expect(view(lensPath(q), set(
lensPath(q), 11, set(
lensPath(q), 10, testObj
)
))).toEqual(11)
})
Typescript test
import {lensPath, view} from 'rambda'
interface Input {
foo: number[]
bar: {
a: string
b: string
}
}
const testObject: Input = {
foo: [1, 2],
bar: {
a: 'x',
b: 'y',
},
}
const path = lensPath(['bar', 'a'])
const pathAsString = lensPath('bar.a')
describe('R.lensPath', () => {
it('happy', () => {
const result = view<Input, string>(path, testObject)
result
})
it('using string as path input', () => {
const result = view<Input, string>(pathAsString, testObject)
result
})
})
lensProp
lensProp(prop: string): {
<T, U>(obj: T): U
It returns a lens that focuses on specified property prop
.
All Typescript definitions
lensProp(prop: string): {
<T, U>(obj: T): U;
set<T, U, V>(val: T, obj: U): V;
};
R.lensProp source
import { assoc } from './assoc.js'
import { lens } from './lens.js'
import { prop } from './prop.js'
export function lensProp(key){
return lens(prop(key), assoc(key))
}
Tests
import { compose } from './compose.js'
import { identity } from './identity.js'
import { inc } from './inc.js'
import { lensProp } from './lensProp.js'
import { over } from './over.js'
import { set } from './set.js'
import { view } from './view.js'
const testObj = {
a : 1,
b : 2,
c : 3,
}
test('focuses object the specified object property', () => {
expect(view(lensProp('a'), testObj)).toEqual(1)
})
test('returns undefined if the specified property does not exist', () => {
expect(view(lensProp('X'), testObj)).toEqual(undefined)
})
test('sets the value of the object property specified', () => {
expect(set(
lensProp('a'), 0, testObj
)).toEqual({
a : 0,
b : 2,
c : 3,
})
})
test('adds the property to the object if it doesn\'t exist', () => {
expect(set(
lensProp('d'), 4, testObj
)).toEqual({
a : 1,
b : 2,
c : 3,
d : 4,
})
})
test('applies function to the value of the specified object property', () => {
expect(over(
lensProp('a'), inc, testObj
)).toEqual({
a : 2,
b : 2,
c : 3,
})
})
test('applies function to undefined and adds the property if it doesn\'t exist', () => {
expect(over(
lensProp('X'), identity, testObj
)).toEqual({
a : 1,
b : 2,
c : 3,
X : undefined,
})
})
test('can be composed', () => {
const nestedObj = {
a : { b : 1 },
c : 2,
}
const composedLens = compose(lensProp('a'), lensProp('b'))
expect(view(composedLens, nestedObj)).toEqual(1)
})
test('set s (get s) === s', () => {
expect(set(
lensProp('a'), view(lensProp('a'), testObj), testObj
)).toEqual(testObj)
})
test('get (set s v) === v', () => {
expect(view(lensProp('a'), set(
lensProp('a'), 0, testObj
))).toEqual(0)
})
test('get (set(set s v1) v2) === v2', () => {
expect(view(lensProp('a'),
set(
lensProp('a'), 11, set(
lensProp('a'), 10, testObj
)
))).toEqual(11)
})
Typescript test
import {lensProp, view} from 'rambda'
interface Input {
foo: string
}
const testObject: Input = {
foo: 'Led Zeppelin',
}
const lens = lensProp('foo')
describe('R.lensProp', () => {
it('happy', () => {
const result = view<Input, string>(lens, testObject)
result
})
})
map
map<T, U>(fn: ObjectIterator<T, U>, iterable: Dictionary<T>): Dictionary<U>
It returns the result of looping through iterable
with fn
.
It works with both array and object.
All Typescript definitions
map<T, U>(fn: ObjectIterator<T, U>, iterable: Dictionary<T>): Dictionary<U>;
map<T, U>(fn: Iterator<T, U>, iterable: T[]): U[];
map<T, U>(fn: Iterator<T, U>): (iterable: T[]) => U[];
map<T, U, S>(fn: ObjectIterator<T, U>): (iterable: Dictionary<T>) => Dictionary<U>;
map<T>(fn: Iterator<T, T>): (iterable: T[]) => T[];
map<T>(fn: Iterator<T, T>, iterable: T[]): T[];
R.map source
import { _isArray } from './_internals/_isArray.js'
import { _keys } from './_internals/_keys.js'
export function mapArray(
fn, list, isIndexed = false
){
let index = 0
const willReturn = Array(list.length)
while (index < list.length){
willReturn[ index ] = isIndexed ? fn(list[ index ], index) : fn(list[ index ])
index++
}
return willReturn
}
export function mapObject(fn, obj){
let index = 0
const keys = _keys(obj)
const len = keys.length
const willReturn = {}
while (index < len){
const key = keys[ index ]
willReturn[ key ] = fn(
obj[ key ], key, obj
)
index++
}
return willReturn
}
export const mapObjIndexed = mapObject
export function map(fn, iterable){
if (arguments.length === 1) return _iterable => map(fn, _iterable)
if (!iterable){
throw new Error('Incorrect iterable input')
}
if (_isArray(iterable)) return mapArray(fn, iterable)
return mapObject(fn, iterable)
}
Tests
import { map as mapRamda } from 'ramda'
import { map } from './map.js'
const double = x => x * 2
describe('with array', () => {
it('happy', () => {
expect(map(double, [ 1, 2, 3 ])).toEqual([ 2, 4, 6 ])
})
it('curried', () => {
expect(map(double)([ 1, 2, 3 ])).toEqual([ 2, 4, 6 ])
})
})
describe('with object', () => {
const obj = {
a : 1,
b : 2,
}
it('happy', () => {
expect(map(double, obj)).toEqual({
a : 2,
b : 4,
})
})
it('property as second and input object as third argument', () => {
const obj = {
a : 1,
b : 2,
}
const iterator = (
val, prop, inputObject
) => {
expect(prop).toBeString()
expect(inputObject).toEqual(obj)
return val * 2
}
expect(map(iterator)(obj)).toEqual({
a : 2,
b : 4,
})
})
})
test('bad inputs difference between Ramda and Rambda', () => {
expect(() => map(double, null)).toThrowWithMessage(Error,
'Incorrect iterable input')
expect(() => map(double)(undefined)).toThrowWithMessage(Error,
'Incorrect iterable input')
expect(() => mapRamda(double, null)).toThrowWithMessage(TypeError,
'Cannot read properties of null (reading \'fantasy-land/map\')')
expect(() => mapRamda(double, undefined)).toThrowWithMessage(TypeError,
'Cannot read properties of undefined (reading \'fantasy-land/map\')')
})
Typescript test
import {map} from 'rambda'
describe('R.map with arrays', () => {
it('iterable returns the same type as the input', () => {
const result = map<number>(
(x: number) => {
x
return x + 2
},
[1, 2, 3]
)
result
})
it('iterable returns the same type as the input - curried', () => {
const result = map<number>((x: number) => {
x
return x + 2
})([1, 2, 3])
result
})
it('iterable returns different type as the input', () => {
const result = map<number, string>(
(x: number) => {
x
return String(x)
},
[1, 2, 3]
)
result
})
})
describe('R.map with objects', () => {
it('iterable with all three arguments - curried', () => {
const result = map<number, string, any>((a, b, c) => {
a
b
c
return `${a}`
})({a: 1, b: 2})
result
})
it('iterable with all three arguments', () => {
const result = map<number, string>(
(a, b, c) => {
a
b
c
return `${a}`
},
{a: 1, b: 2}
)
result
})
it('iterable with property argument', () => {
const result = map<number, string>(
(a, b) => {
a
b
return `${a}`
},
{a: 1, b: 2}
)
result
})
it('iterable with no property argument', () => {
const result = map<number, string>(
a => {
a
return `${a}`
},
{a: 1, b: 2}
)
result
})
})
Rambda is fastest. Ramda is 86.6% slower and Lodash is 11.73% slower
const R = require('../../dist/rambda.js')
const arr = [ 1, 2, 3, 4 ]
const fn = x => x * 2
const map = [
{
label : 'Rambda',
fn : () => {
R.map(fn, arr)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.map(fn, arr)
},
},
{
label : 'Lodash',
fn : () => {
_.map(arr, fn)
},
},
]
mapObjIndexed
It works the same way as R.map
does for objects. It is added as Ramda also has this method.
match
match(regExpression: RegExp, str: string): string[]
Curried version of String.prototype.match
which returns empty array, when there is no match.
All Typescript definitions
match(regExpression: RegExp, str: string): string[];
match(regExpression: RegExp): (str: string) => string[];
R.match source
export function match(pattern, input){
if (arguments.length === 1) return _input => match(pattern, _input)
const willReturn = input.match(pattern)
return willReturn === null ? [] : willReturn
}
Tests
import { equals } from './equals.js'
import { match } from './match.js'
test('happy', () => {
expect(match(/a./g)('foo bar baz')).toEqual([ 'ar', 'az' ])
})
test('fallback', () => {
expect(match(/a./g)('foo')).toEqual([])
})
test('with string', () => {
expect(match('a', 'foo')).toEqual([])
expect(equals(match('o', 'foo'), [ 'o' ])).toBeTrue()
})
test('throwing', () => {
expect(() => {
match(/a./g, null)
}).toThrowWithMessage(TypeError,
'Cannot read properties of null (reading \'match\')')
})
Typescript test
import {match} from 'rambda'
const str = 'foo bar'
describe('R.match', () => {
it('happy', () => {
const result = match(/foo/, str)
result
})
it('curried', () => {
const result = match(/foo/)(str)
result
})
})
Rambda is faster than Ramda with 44.83%
const R = require('../../dist/rambda.js')
const match = [
{
label : 'Rambda',
fn : () => {
R.match(/a./g)('foo bar baz')
R.match(/a./g, 'foo bar baz')
},
},
{
label : 'Ramda',
fn : () => {
Ramda.match(/a./g)('foo bar baz')
Ramda.match(/a./g, 'foo bar baz')
},
},
]
mathMod
R.mathMod
behaves like the modulo operator should mathematically, unlike the %
operator (and by extension, R.modulo
). So while -17 % 5
is -2
, mathMod(-17, 5)
is 3
.
max
It returns the greater value between x
and y
.
maxBy
It returns the greater value between x
and y
according to compareFn
function.
mean
mean(list: number[]): number
It returns the mean value of list
input.
All Typescript definitions
mean(list: number[]): number;
R.mean source
import { sum } from './sum.js'
export function mean(list){
return sum(list) / list.length
}
Tests
import { mean } from './mean.js'
test('happy', () => {
expect(mean([ 2, 7 ])).toBe(4.5)
})
test('with NaN', () => {
expect(mean([])).toBeNaN()
})
Typescript test
import {mean} from 'rambda'
describe('R.mean', () => {
it('happy', () => {
const result = mean([1, 2, 3])
result
})
})
median
median(list: number[]): number
It returns the median value of list
input.
All Typescript definitions
median(list: number[]): number;
R.median source
import { mean } from './mean.js'
export function median(list){
const len = list.length
if (len === 0) return NaN
const width = 2 - len % 2
const idx = (len - width) / 2
return mean(Array.prototype.slice
.call(list, 0)
.sort((a, b) => {
if (a === b) return 0
return a < b ? -1 : 1
})
.slice(idx, idx + width))
}
Tests
import { median } from './median.js'
test('happy', () => {
expect(median([ 2 ])).toEqual(2)
expect(median([ 7, 2, 10, 2, 9 ])).toEqual(7)
})
test('with empty array', () => {
expect(median([])).toBeNaN()
})
Typescript test
import {median} from 'rambda'
describe('R.median', () => {
it('happy', () => {
const result = median([1, 2, 3])
result
})
})
merge
Same as R.mergeRight
.
mergeAll
mergeAll<T>(list: object[]): T
It merges all objects of list
array sequentially and returns the result.
All Typescript definitions
mergeAll<T>(list: object[]): T;
mergeAll(list: object[]): object;
R.mergeAll source
import { map } from './map.js'
import { mergeRight } from './mergeRight.js'
export function mergeAll(arr){
let willReturn = {}
map(val => {
willReturn = mergeRight(willReturn, val)
}, arr)
return willReturn
}
Tests
import { mergeAll } from './mergeAll.js'
test('case 1', () => {
const arr = [ { a : 1 }, { b : 2 }, { c : 3 } ]
const expectedResult = {
a : 1,
b : 2,
c : 3,
}
expect(mergeAll(arr)).toEqual(expectedResult)
})
test('case 2', () => {
expect(mergeAll([ { foo : 1 }, { bar : 2 }, { baz : 3 } ])).toEqual({
foo : 1,
bar : 2,
baz : 3,
})
})
Typescript test
import {mergeAll} from 'rambda'
describe('R.mergeAll', () => {
it('with passing type', () => {
interface Output {
foo: number
bar: number
}
const result = mergeAll<Output>([{foo: 1}, {bar: 2}])
result.foo
result.bar
})
it('without passing type', () => {
const result = mergeAll([{foo: 1}, {bar: 2}])
result
})
})
mergeDeepRight
mergeDeepRight<Output>(target: object, newProps: object): Output
Creates a new object with the own properties of the first object merged with the own properties of the second object. If a key exists in both objects:
- and both values are objects, the two values will be recursively merged
- otherwise the value from the second object will be used.
All Typescript definitions
mergeDeepRight<Output>(target: object, newProps: object): Output;
mergeDeepRight<Output>(target: object): (newProps: object) => Output;
R.mergeDeepRight source
import { type } from './type.js'
export function mergeDeepRight(target, source){
if (arguments.length === 1){
return sourceHolder => mergeDeepRight(target, sourceHolder)
}
const willReturn = JSON.parse(JSON.stringify(target))
Object.keys(source).forEach(key => {
if (type(source[ key ]) === 'Object'){
if (type(target[ key ]) === 'Object'){
willReturn[ key ] = mergeDeepRight(target[ key ], source[ key ])
} else {
willReturn[ key ] = source[ key ]
}
} else {
willReturn[ key ] = source[ key ]
}
})
return willReturn
}
Tests
import { mergeDeepRight } from './mergeDeepRight.js'
const slave = {
name : 'evilMe',
age : 10,
contact : {
a : 1,
email : 'foo@example.com',
},
}
const master = {
age : 40,
contact : { email : 'baz@example.com' },
songs : { title : 'Remains the same' },
}
test('happy', () => {
const result = mergeDeepRight(slave, master)
const curryResult = mergeDeepRight(slave)(master)
const expected = {
age : 40,
name : 'evilMe',
contact : {
a : 1,
email : 'baz@example.com',
},
songs : { title : 'Remains the same' },
}
expect(result).toEqual(expected)
expect(curryResult).toEqual(expected)
})
test('ramda compatible test 1', () => {
const a = {
w : 1,
x : 2,
y : { z : 3 },
}
const b = {
a : 4,
b : 5,
c : { d : 6 },
}
const result = mergeDeepRight(a, b)
const expected = {
w : 1,
x : 2,
y : { z : 3 },
a : 4,
b : 5,
c : { d : 6 },
}
expect(result).toEqual(expected)
})
test('ramda compatible test 2', () => {
const a = {
a : {
b : 1,
c : 2,
},
y : 0,
}
const b = {
a : {
b : 3,
d : 4,
},
z : 0,
}
const result = mergeDeepRight(a, b)
const expected = {
a : {
b : 3,
c : 2,
d : 4,
},
y : 0,
z : 0,
}
expect(result).toEqual(expected)
})
test('ramda compatible test 3', () => {
const a = {
w : 1,
x : { y : 2 },
}
const result = mergeDeepRight(a, { x : { y : 3 } })
const expected = {
w : 1,
x : { y : 3 },
}
expect(result).toEqual(expected)
})
Typescript test
import {mergeDeepRight} from 'rambda'
interface Output {
foo: {
bar: number
}
}
describe('R.mergeDeepRight', () => {
const result = mergeDeepRight<Output>({foo: {bar: 1}}, {foo: {bar: 2}})
result.foo.bar
})
mergeLeft
mergeLeft<Output>(newProps: object, target: object): Output
Same as R.merge
, but in opposite direction.
All Typescript definitions
mergeLeft<Output>(newProps: object, target: object): Output;
mergeLeft<Output>(newProps: object): (target: object) => Output;
R.mergeLeft source
import { mergeRight } from './mergeRight.js'
export function mergeLeft(x, y){
if (arguments.length === 1) return _y => mergeLeft(x, _y)
return mergeRight(y, x)
}
Tests
import { mergeLeft } from './mergeLeft.js'
const obj = {
foo : 1,
bar : 2,
}
test('happy', () => {
expect(mergeLeft({ bar : 20 }, obj)).toEqual({
foo : 1,
bar : 20,
})
})
test('curry', () => {
expect(mergeLeft({ baz : 3 })(obj)).toEqual({
foo : 1,
bar : 2,
baz : 3,
})
})
test('when undefined or null instead of object', () => {
expect(mergeLeft(null, undefined)).toEqual({})
expect(mergeLeft(obj, null)).toEqual(obj)
expect(mergeLeft(obj, undefined)).toEqual(obj)
expect(mergeLeft(undefined, obj)).toEqual(obj)
})
Typescript test
import {mergeLeft} from 'rambda'
interface Output {
foo: number
bar: number
}
describe('R.mergeLeft', () => {
const result = mergeLeft<Output>({foo: 1}, {bar: 2})
const curriedResult = mergeLeft<Output>({foo: 1})({bar: 2})
result.foo
result.bar
curriedResult.bar
})
mergeRight
It creates a copy of target
object with overidden newProps
properties. Previously known as R.merge
but renamed after Ramda did the same.
mergeWith
mergeWith(fn: (x: any, z: any) => any, a: Obj, b: Record<string, unknown>): Obj
It takes two objects and a function, which will be used when there is an overlap between the keys.
All Typescript definitions
mergeWith(fn: (x: any, z: any) => any, a: Obj, b: Record<string, unknown>): Obj;
mergeWith<Output>(fn: (x: any, z: any) => any, a: Obj, b: Record<string, unknown>): Output;
mergeWith(fn: (x: any, z: any) => any, a: Record<string, unknown>): (b: Record<string, unknown>) => Obj;
mergeWith<Output>(fn: (x: any, z: any) => any, a: Record<string, unknown>): (b: Record<string, unknown>) => Output;
mergeWith(fn: (x: any, z: any) => any): <U, V>(a: U, b: V) => Obj;
mergeWith<Output>(fn: (x: any, z: any) => any): <U, V>(a: U, b: V) => Output;
R.mergeWith source
import { curry } from './curry.js'
function mergeWithFn(
mergeFn, a, b
){
const willReturn = {}
Object.keys(a).forEach(key => {
if (b[ key ] === undefined){
willReturn[ key ] = a[ key ]
} else {
willReturn[ key ] = mergeFn(a[ key ], b[ key ])
}
})
Object.keys(b).forEach(key => {
if (willReturn[ key ] !== undefined) return
if (a[ key ] === undefined){
willReturn[ key ] = b[ key ]
} else {
willReturn[ key ] = mergeFn(a[ key ], b[ key ])
}
})
return willReturn
}
export const mergeWith = curry(mergeWithFn)
Tests
import { concat } from './concat.js'
import { mergeWith } from './mergeWith.js'
test('happy', () => {
const result = mergeWith(
concat,
{
a : true,
values : [ 10, 20 ],
},
{
b : true,
values : [ 15, 35 ],
}
)
const expected = {
a : true,
values : [ 10, 20, 15, 35 ],
b : true,
}
expect(result).toEqual(expected)
})
Typescript test
import {concat, mergeWith} from 'rambda'
interface Output {
a: boolean,
b: boolean,
values: number[],
}
const A = {
a: true,
values: [10, 20],
}
const B = {
b: true,
values: [15, 35],
}
describe('R.mergeWith', () => {
test('no curry | without explicit types', () => {
const result = mergeWith(concat, A, B)
result
})
test('no curry | with explicit types', () => {
const result = mergeWith<Output>(concat, A, B)
result
})
test('curry 1 | without explicit types', () => {
const result = mergeWith(concat, A)(B)
result
})
test('curry 1 | with explicit types', () => {
const result = mergeWith<Output>(concat, A)(B)
result
})
test('curry 2 | without explicit types', () => {
const result = mergeWith(concat)(A, B)
result
})
test('curry 2 | with explicit types', () => {
const result = mergeWith<Output>(concat)(A, B)
result
})
})
min
It returns the lesser value between x
and y
.
minBy
It returns the lesser value between x
and y
according to compareFn
function.
modulo
Curried version of x%y
.
move
It returns a copy of list
with exchanged fromIndex
and toIndex
elements.
multiply
Curried version of x*y
.
negate
none
none<T>(predicate: (x: T) => boolean, list: T[]): boolean
It returns true
, if all members of array list
returns false
, when applied as argument to predicate
function.
All Typescript definitions
none<T>(predicate: (x: T) => boolean, list: T[]): boolean;
none<T>(predicate: (x: T) => boolean): (list: T[]) => boolean;
R.none source
export function none(predicate, list){
if (arguments.length === 1) return _list => none(predicate, _list)
for (let i = 0; i < list.length; i++){
if (predicate(list[ i ])) return false
}
return true
}
Tests
import {none} from './none.js'
const isEven = n => n % 2 === 0
test('when true', () => {
expect(none(isEven, [1, 3, 5, 7])).toBeTrue()
})
test('when false curried', () => {
expect(none(input => input > 1, [1, 2, 3])).toBeFalse()
})
Typescript test
import {none} from 'rambda'
describe('R.none', () => {
it('happy', () => {
const result = none(
x => {
x
return x > 0
},
[1, 2, 3]
)
result
})
it('curried needs a type', () => {
const result = none<number>(x => {
x
return x > 0
})([1, 2, 3])
result
})
})
Rambda is faster than Ramda with 96.48%
const R = require('../../dist/rambda.js')
const isEven = n => n % 2 === 0
const arr = [ 1, 3, 5, 7, 9, 11 ]
const none = [
{
label : 'Rambda',
fn : () => {
R.none(isEven, arr)
R.none(isEven)(arr)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.none(isEven, arr)
Ramda.none(isEven)(arr)
},
},
]
not
not(input: any): boolean
It returns a boolean negated version of input
.
All Typescript definitions
not(input: any): boolean;
R.not source
export function not(input){
return !input
}
Tests
import {not} from './not.js'
test('not', () => {
expect(not(false)).toBeTrue()
expect(not(true)).toBeFalse()
expect(not(0)).toBeTrue()
expect(not(1)).toBeFalse()
})
Typescript test
import {not} from 'rambda'
describe('R.not', () => {
it('happy', () => {
const result = not(4)
result
})
})
nth
nth(index: number, input: string): string
Curried version of input[index]
.
All Typescript definitions
nth(index: number, input: string): string;
nth<T>(index: number, input: T[]): T | undefined;
nth(n: number): {
<T>(input: T[]): T | undefined;
(input: string): string;
};
R.nth source
export function nth(index, input){
if (arguments.length === 1) return _input => nth(index, _input)
const idx = index < 0 ? input.length + index : index
return Object.prototype.toString.call(input) === '[object String]' ?
input.charAt(idx) :
input[ idx ]
}
Tests
import { nth } from './nth.js'
test('happy', () => {
expect(nth(2, [ 1, 2, 3, 4 ])).toEqual(3)
})
test('with curry', () => {
expect(nth(2)([ 1, 2, 3, 4 ])).toEqual(3)
})
test('with string and correct index', () => {
expect(nth(2)('foo')).toEqual('o')
})
test('with string and invalid index', () => {
expect(nth(20)('foo')).toEqual('')
})
test('with negative index', () => {
expect(nth(-3)([ 1, 2, 3, 4 ])).toEqual(2)
})
Typescript test
import {nth} from 'rambda'
const list = [1, 2, 3]
describe('R.nth', () => {
it('happy', () => {
const result = nth(4, list)
result
})
it('curried', () => {
const result = nth(1)(list)
result
})
})
describe('R.nth - string', () => {
const str = 'abc'
it('happy', () => {
const result = nth(4, str)
result
})
it('curried', () => {
const result = nth(1)(str)
result
})
})
objOf
It creates an object with a single key-value pair.
of
of<T>(x: T): T[]
All Typescript definitions
of<T>(x: T): T[];
R.of source
export function of(value){
return [ value ]
}
Tests
import { of } from './of.js'
test('happy', () => {
expect(of(3)).toEqual([ 3 ])
expect(of(null)).toEqual([ null ])
})
Typescript test
import {of} from 'ramda'
const list = [1, 2, 3]
describe('R.of', () => {
it('happy', () => {
const result = of(4)
result
})
it('curried', () => {
const result = of(list)
result
})
})
omit
omit<T, K extends string>(propsToOmit: K[], obj: T): Omit<T, K>
It returns a partial copy of an obj
without propsToOmit
properties.
All Typescript definitions
omit<T, K extends string>(propsToOmit: K[], obj: T): Omit<T, K>;
omit<K extends string>(propsToOmit: K[]): <T>(obj: T) => Omit<T, K>;
omit<T, U>(propsToOmit: string, obj: T): U;
omit<T, U>(propsToOmit: string): (obj: T) => U;
omit<T>(propsToOmit: string, obj: object): T;
omit<T>(propsToOmit: string): (obj: object) => T;
R.omit source
import { createPath } from './_internals/createPath.js'
export function omit(propsToOmit, obj){
if (arguments.length === 1) return _obj => omit(propsToOmit, _obj)
if (obj === null || obj === undefined){
return undefined
}
const propsToOmitValue = createPath(propsToOmit, ',')
const willReturn = {}
for (const key in obj){
if (!propsToOmitValue.includes(key)){
willReturn[ key ] = obj[ key ]
}
}
return willReturn
}
Tests
import { omit } from './omit.js'
test('with string as condition', () => {
const obj = {
a : 1,
b : 2,
c : 3,
}
const result = omit('a,c', obj)
const resultCurry = omit('a,c')(obj)
const expectedResult = { b : 2 }
expect(result).toEqual(expectedResult)
expect(resultCurry).toEqual(expectedResult)
})
test('with null', () => {
expect(omit('a,b', null)).toEqual(undefined)
})
test('doesn\'t work with number as property', () => {
expect(omit([ 42 ], {
a : 1,
42 : 2,
})).toEqual({
42 : 2,
a : 1,
})
})
test('happy', () => {
expect(omit([ 'a', 'c' ])({
a : 'foo',
b : 'bar',
c : 'baz',
})).toEqual({ b : 'bar' })
})
Typescript test
import {omit} from 'rambda'
describe('R.omit with array as props input', () => {
it('allow Typescript to infer object type', () => {
const input = {a: 'foo', b: 2, c: 3, d: 4}
const result = omit(['b,c'], input)
result.a
result.d
const curriedResult = omit(['a,c'], input)
curriedResult.a
curriedResult.d
})
it('declare type of input object', () => {
interface Input {
a: string
b: number
c: number
d: number
}
const input: Input = {a: 'foo', b: 2, c: 3, d: 4}
const result = omit(['b,c'], input)
result
result.a
result.d
const curriedResult = omit(['a,c'], input)
curriedResult.a
curriedResult.d
})
})
describe('R.omit with string as props input', () => {
interface Output {
b: number
d: number
}
it('explicitly declare output', () => {
const result = omit<Output>('a,c', {a: 1, b: 2, c: 3, d: 4})
result
result.b
const curriedResult = omit<Output>('a,c')({a: 1, b: 2, c: 3, d: 4})
curriedResult.b
})
it('explicitly declare input and output', () => {
interface Input {
a: number
b: number
c: number
d: number
}
const result = omit<Input, Output>('a,c', {a: 1, b: 2, c: 3, d: 4})
result
result.b
const curriedResult = omit<Input, Output>('a,c')({
a: 1,
b: 2,
c: 3,
d: 4,
})
curriedResult.b
})
it('without passing type', () => {
const result = omit('a,c', {a: 1, b: 2, c: 3, d: 4})
result
})
})
Rambda is fastest. Ramda is 69.95% slower and Lodash is 97.34% slower
const R = require('../../dist/rambda.js')
const obj = {
a : 'foo',
b : 'bar',
c : 'baz',
}
const toOmit = [ 'a', 'c' ]
const omit = [
{
label : 'Rambda',
fn : () => {
R.omit(toOmit, obj)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.omit(toOmit, obj)
},
},
{
label : 'Lodash',
fn : () => {
_.omit(obj, toOmit)
},
},
]
on
It passes the two inputs through unaryFn
and then the results are passed as inputs the the binaryFn
to receive the final result(binaryFn(unaryFn(FIRST_INPUT), unaryFn(SECOND_INPUT))
).
This method is also known as P combinator.
once
once<T extends (...args: any[]) => any>(func: T): T
It returns a function, which invokes only once fn
function.
All Typescript definitions
once<T extends (...args: any[]) => any>(func: T): T;
R.once source
import { curry } from './curry.js'
function onceFn(fn, context){
let result
return function (){
if (fn){
result = fn.apply(context || this, arguments)
fn = null
}
return result
}
}
export function once(fn, context){
if (arguments.length === 1){
const wrap = onceFn(fn, context)
return curry(wrap)
}
return onceFn(fn, context)
}
Tests
import { once } from './once.js'
test('with counter', () => {
let counter = 0
const runOnce = once(x => {
counter++
return x + 2
})
expect(runOnce(1)).toEqual(3)
runOnce(1)
runOnce(1)
runOnce(1)
expect(counter).toEqual(1)
})
test('happy path', () => {
const addOneOnce = once((
a, b, c
) => a + b + c, 1)
expect(addOneOnce(
10, 20, 30
)).toBe(60)
expect(addOneOnce(40)).toEqual(60)
})
Typescript test
import {once} from 'rambda'
describe('R.once', () => {
it('happy', () => {
const runOnce = once((x: number) => {
return x + 2
})
const result = runOnce(1)
result
})
})
or
Logical OR
over
over<T>(lens: Lens, fn: Arity1Fn, value: T): T
It returns a copied Object or Array with modified value received by applying function fn
to lens
focus.
All Typescript definitions
over<T>(lens: Lens, fn: Arity1Fn, value: T): T;
over<T>(lens: Lens, fn: Arity1Fn, value: T[]): T[];
over(lens: Lens, fn: Arity1Fn): <T>(value: T) => T;
over(lens: Lens, fn: Arity1Fn): <T>(value: T[]) => T[];
over(lens: Lens): <T>(fn: Arity1Fn, value: T) => T;
over(lens: Lens): <T>(fn: Arity1Fn, value: T[]) => T[];
R.over source
import { curry } from './curry.js'
const Identity = x => ({
x,
map : fn => Identity(fn(x)),
})
function overFn(
lens, fn, object
){
return lens(x => Identity(fn(x)))(object).x
}
export const over = curry(overFn)
Tests
import { assoc } from './assoc.js'
import { lens } from './lens.js'
import { lensIndex } from './lensIndex.js'
import { lensPath } from './lensPath.js'
import { over } from './over.js'
import { prop } from './prop.js'
import { toUpper } from './toUpper.js'
const testObject = {
foo : 'bar',
baz : {
a : 'x',
b : 'y',
},
}
test('assoc lens', () => {
const assocLens = lens(prop('foo'), assoc('foo'))
const result = over(
assocLens, toUpper, testObject
)
const expected = {
...testObject,
foo : 'BAR',
}
expect(result).toEqual(expected)
})
test('path lens', () => {
const pathLens = lensPath('baz.a')
const result = over(
pathLens, toUpper, testObject
)
const expected = {
...testObject,
baz : {
a : 'X',
b : 'y',
},
}
expect(result).toEqual(expected)
})
test('index lens', () => {
const indexLens = lensIndex(0)
const result = over(indexLens, toUpper)([ 'foo', 'bar' ])
expect(result).toEqual([ 'FOO', 'bar' ])
})
Rambda is faster than Ramda with 56.23%
const R = require('../../dist/rambda.js')
const testObj = { a : 1 }
const last = [
{
label : 'Rambda',
fn : () => {
R.over(
R.lensProp('a'), R.inc, testObj
)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.over(
Ramda.lensProp('a'), Ramda.inc, testObj
)
},
},
]
partial
partial<V0, V1, T>(fn: (x0: V0, x1: V1) => T, args: [V0]): (x1: V1) => T
It is very similar to R.curry
, but you can pass initial arguments when you create the curried function.
R.partial
will keep returning a function until all the arguments that the function fn
expects are passed.
The name comes from the fact that you partially inject the inputs.
All Typescript definitions
partial<V0, V1, T>(fn: (x0: V0, x1: V1) => T, args: [V0]): (x1: V1) => T;
partial<V0, V1, V2, T>(fn: (x0: V0, x1: V1, x2: V2) => T, args: [V0, V1]): (x2: V2) => T;
partial<V0, V1, V2, T>(fn: (x0: V0, x1: V1, x2: V2) => T, args: [V0]): (x1: V1, x2: V2) => T;
partial<V0, V1, V2, V3, T>(fn: (x0: V0, x1: V1, x2: V2, x3: V3) => T, args: [V0, V1, V2]): (x2: V3) => T;
partial<V0, V1, V2, V3, T>(fn: (x0: V0, x1: V1, x2: V2, x3: V3) => T, args: [V0, V1]): (x2: V2, x3: V3) => T;
partial<V0, V1, V2, V3, T>(fn: (x0: V0, x1: V1, x2: V2, x3: V3) => T, args: [V0]): (x1: V1, x2: V2, x3: V3) => T;
partial<T>(fn: (...a: any[]) => T, args: any[]): (...x: any[]) => T;
R.partial source
export function partial(fn, ...args){
const len = fn.length
return (...rest) => {
if (args.length + rest.length >= len){
return fn(...args, ...rest)
}
return partial(fn, ...[ ...args, ...rest ])
}
}
Tests
import { partial } from './partial.js'
import { type } from './type.js'
const greet = (
salutation, title, firstName, lastName
) =>
salutation + ', ' + title + ' ' + firstName + ' ' + lastName + '!'
test('happy', () => {
const canPassAnyNumberOfArguments = partial(
greet, 'Hello', 'Ms.'
)
const fn = canPassAnyNumberOfArguments('foo')
const sayHello = partial(greet, [ 'Hello' ])
const sayHelloRamda = partial(sayHello, [ 'Ms.' ])
expect(type(fn)).toBe('Function')
expect(fn('bar')).toBe('Hello, Ms. foo bar!')
expect(sayHelloRamda('foo', 'bar')).toBe('Hello, Ms. foo bar!')
})
test('extra arguments are ignored', () => {
const canPassAnyNumberOfArguments = partial(
greet, 'Hello', 'Ms.'
)
const fn = canPassAnyNumberOfArguments('foo')
expect(type(fn)).toBe('Function')
expect(fn(
'bar', 1, 2
)).toBe('Hello, Ms. foo bar!')
})
test('when array is input', () => {
const fooFn = (
a, b, c, d
) => ({
a,
b,
c,
d,
})
const barFn = partial(
fooFn, [ 1, 2 ], []
)
expect(barFn(1, 2)).toEqual({
a : [ 1, 2 ],
b : [],
c : 1,
d : 2,
})
})
test('ramda spec', () => {
const sayHello = partial(greet, 'Hello')
const sayHelloToMs = partial(sayHello, 'Ms.')
expect(sayHelloToMs('Jane', 'Jones')).toBe('Hello, Ms. Jane Jones!')
})
Typescript test
import {partial} from 'rambda'
describe('R.partial', () => {
it('happy', () => {
function greet(
salutation: string,
title: string,
firstName: string,
lastName: string
) {
return `${salutation}, ${title} ${firstName} ${lastName}!`
}
const sayHello = partial(greet, ['Hello'])
const sayHelloToMs = partial(sayHello, ['Ms.'])
const result = sayHelloToMs('Jane', 'Jones')
result
})
})
partialObject
partialObject<Input, PartialInput, Output>(
fn: (input: Input) => Output,
partialInput: PartialInput,
): (input: Pick<Input, Exclude<keyof Input, keyof PartialInput>>) => Output
R.partialObject
is a curry helper designed specifically for functions accepting object as a single argument.
Initially the function knows only a part from the whole input object and then R.partialObject
helps in preparing the function for the second part, when it receives the rest of the input.
All Typescript definitions
partialObject<Input, PartialInput, Output>(
fn: (input: Input) => Output,
partialInput: PartialInput,
): (input: Pick<Input, Exclude<keyof Input, keyof PartialInput>>) => Output;
R.partialObject source
import { mergeDeepRight } from './mergeDeepRight.js'
import { type } from './type.js'
export function partialObject(fn, input){
return rest => {
if (type(fn) === 'Async'){
return new Promise((resolve, reject) => {
fn(mergeDeepRight(rest, input)).then(resolve)
.catch(reject)
})
}
return fn(mergeDeepRight(rest, input))
}
}
Tests
import {delay} from './delay.js'
import {partialObject} from './partialObject.js'
import {type} from './type.js'
test('with plain function', () => {
const fn = ({a, b, c}) => a + b + c
const curried = partialObject(fn, {a: 1})
expect(type(curried)).toEqual('Function')
expect(
curried({
b: 2,
c: 3,
})
).toEqual(6)
})
test('with function that throws an error', () => {
const fn = ({a, b, c}) => {
throw new Error('foo')
}
const curried = partialObject(fn, {a: 1})
expect(type(curried)).toEqual('Function')
expect(() =>
curried({
b: 2,
c: 3,
})
).toThrowWithMessage(Error, 'foo')
})
test('with async', async () => {
const fn = async ({a, b, c}) => {
await delay(100)
return a + b + c
}
const curried = partialObject(fn, {a: 1})
const result = await curried({
b: 2,
c: 3,
})
expect(result).toEqual(6)
})
test('async function throwing an error', async () => {
const fn = async ({a, b, c}) => {
await delay(100)
throw new Error('foo')
}
const curried = partialObject(fn, {a: 1})
try {
await curried({
b: 2,
c: 3,
})
expect(true).toBeFalsy()
} catch (e) {
expect(e.message).toBe('foo')
}
})
Typescript test
import {partialObject, delay} from 'rambda'
describe('R.partialObject', () => {
it('happy', () => {
interface Input {
a: number,
b: number,
c: string,
}
const fn = ({a, b, c}: Input) => a + b + c
const curried = partialObject(fn, {a: 1})
const result = curried({
b: 2,
c: 'foo',
})
result
})
it('asynchronous', async() => {
interface Input {
a: number,
b: number,
c: string,
}
const fn = async({a, b, c}: Input) => {
await delay(100)
return a + b + c
}
const curried = partialObject(fn, {a: 1})
const result = await curried({
b: 2,
c: 'foo',
})
result
})
})
partition
partition<T>(
predicate: Predicate<T>,
input: T[]
): [T[], T[]]
It will return array of two objects/arrays according to predicate
function. The first member holds all instances of input
that pass the predicate
function, while the second member - those who doesn't.
All Typescript definitions
partition<T>(
predicate: Predicate<T>,
input: T[]
): [T[], T[]];
partition<T>(
predicate: Predicate<T>
): (input: T[]) => [T[], T[]];
partition<T>(
predicate: (x: T, prop?: string) => boolean,
input: { [key: string]: T}
): [{ [key: string]: T}, { [key: string]: T}];
partition<T>(
predicate: (x: T, prop?: string) => boolean
): (input: { [key: string]: T}) => [{ [key: string]: T}, { [key: string]: T}];
R.partition source
import { _isArray } from './_internals/_isArray.js'
export function partitionObject(predicate, iterable){
const yes = {}
const no = {}
Object.entries(iterable).forEach(([ prop, value ]) => {
if (predicate(value, prop)){
yes[ prop ] = value
} else {
no[ prop ] = value
}
})
return [ yes, no ]
}
export function partitionArray(
predicate, list, indexed = false
){
const yes = []
const no = []
let counter = -1
while (counter++ < list.length - 1){
if (
indexed ? predicate(list[ counter ], counter) : predicate(list[ counter ])
){
yes.push(list[ counter ])
} else {
no.push(list[ counter ])
}
}
return [ yes, no ]
}
export function partition(predicate, iterable){
if (arguments.length === 1){
return listHolder => partition(predicate, listHolder)
}
if (!_isArray(iterable)) return partitionObject(predicate, iterable)
return partitionArray(predicate, iterable)
}
Tests
import { partition } from './partition.js'
test('with array', () => {
const predicate = x => x > 2
const list = [ 1, 2, 3, 4 ]
const result = partition(predicate, list)
const expectedResult = [
[ 3, 4 ],
[ 1, 2 ],
]
expect(result).toEqual(expectedResult)
})
test('with object', () => {
const predicate = (value, prop) => {
expect(typeof prop).toBe('string')
return value > 2
}
const hash = {
a : 1,
b : 2,
c : 3,
d : 4,
}
const result = partition(predicate)(hash)
const expectedResult = [
{
c : 3,
d : 4,
},
{
a : 1,
b : 2,
},
]
expect(result).toEqual(expectedResult)
})
test('readme example', () => {
const list = [ 1, 2, 3 ]
const obj = {
a : 1,
b : 2,
c : 3,
}
const predicate = x => x > 2
const result = [ partition(predicate, list), partition(predicate, obj) ]
const expected = [
[ [ 3 ], [ 1, 2 ] ],
[
{ c : 3 },
{
a : 1,
b : 2,
},
],
]
expect(result).toEqual(expected)
})
Typescript test
import {partition} from 'rambda'
describe('R.partition', () => {
it('with array', () => {
const predicate = (x: number) => {
return x > 2
}
const list = [1, 2, 3, 4]
const result = partition(predicate, list)
const curriedResult = partition(predicate)(list)
result
curriedResult
})
})
path
path<Input, T>(pathToSearch: Path, obj: Input): T | undefined
If pathToSearch
is 'a.b'
then it will return 1
if obj
is {a:{b:1}}
.
It will return undefined
, if such path is not found.
All Typescript definitions
path<Input, T>(pathToSearch: Path, obj: Input): T | undefined;
path<T>(pathToSearch: Path, obj: any): T | undefined;
path<T>(pathToSearch: Path): (obj: any) => T | undefined;
path<Input, T>(pathToSearch: Path): (obj: Input) => T | undefined;
R.path source
import { createPath } from './_internals/createPath.js'
export function path(pathInput, obj){
if (arguments.length === 1) return _obj => path(pathInput, _obj)
if (obj === null || obj === undefined){
return undefined
}
let willReturn = obj
let counter = 0
const pathArrValue = createPath(pathInput)
while (counter < pathArrValue.length){
if (willReturn === null || willReturn === undefined){
return undefined
}
if (willReturn[ pathArrValue[ counter ] ] === null) return undefined
willReturn = willReturn[ pathArrValue[ counter ] ]
counter++
}
return willReturn
}
Tests
import { path } from './path.js'
test('with array inside object', () => {
const obj = { a : { b : [ 1, { c : 1 } ] } }
expect(path('a.b.1.c', obj)).toBe(1)
})
test('works with undefined', () => {
const obj = { a : { b : { c : 1 } } }
expect(path('a.b.c.d.f', obj)).toBeUndefined()
expect(path('foo.babaz', undefined)).toBeUndefined()
expect(path('foo.babaz')(undefined)).toBeUndefined()
})
test('works with string instead of array', () => {
expect(path('foo.bar.baz')({ foo : { bar : { baz : 'yes' } } })).toEqual('yes')
})
test('path', () => {
expect(path([ 'foo', 'bar', 'baz' ])({ foo : { bar : { baz : 'yes' } } })).toEqual('yes')
expect(path([ 'foo', 'bar', 'baz' ])(null)).toBeUndefined()
expect(path([ 'foo', 'bar', 'baz' ])({ foo : { bar : 'baz' } })).toBeUndefined()
})
test('null is not a valid path', () => {
expect(path('audio_tracks', {
a : 1,
audio_tracks : null,
})).toBeUndefined()
})
Typescript test
import {path} from 'rambda'
interface Input {
a: number
b: {
c: boolean
}
}
describe('R.path', () => {
it('without specified input type', () => {
const input = {a: 1, b: {c: true}}
const result = path<boolean>('a.b.c', input)
const curriedResult = path<boolean>('a.b.c')(input)
result
curriedResult
})
it('without specified output type', () => {
const input = {a: 1, b: {c: true}}
const result = path('a.b.c', input)
result
})
it('with string as path', () => {
const input: Input = {a: 1, b: {c: true}}
const resultA = path<boolean>('a.b.c', input)
const resultB = path<boolean>('a.b.c')(input)
resultA
resultB
})
it('with array as path', () => {
const input: Input = {a: 1, b: {c: true}}
const resultA = path<boolean>(['a', 'b', 'c'], input)
const resultB = path<boolean>(['a', 'b', 'c'])(input)
resultA
resultB
})
})
describe('path with specified input', () => {
it('with string as path', () => {
const input: Input = {a: 1, b: {c: true}}
const resultA = path<Input, boolean>('a.b.c', input)
const resultB = path<Input, boolean>('a.b.c')(input)
resultA
resultB
})
it('with array as path', () => {
const input: Input = {a: 1, b: {c: true}}
const resultA = path<Input, boolean>(['a', 'b', 'c'], input)
const resultB = path<Input, boolean>(['a', 'b', 'c'])(input)
resultA
resultB
})
})
Lodash is fastest. Rambda is 37.81% slower and Ramda is 77.81% slower
const R = require('../../dist/rambda.js')
const obj = { a : { b : 2 } }
const pathInput = [ 'a', 'b' ]
const path = [
{
label : 'Rambda',
fn : () => {
R.path(pathInput, obj)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.path(pathInput, obj)
},
},
{
label : 'Lodash',
fn : () => {
_.get(obj, pathInput)
},
},
]
pathEq
pathEq(pathToSearch: Path, target: any, input: any): boolean
It returns true
if pathToSearch
of input
object is equal to target
value.
pathToSearch
is passed to R.path
, which means that it can be either a string or an array. Also equality between target
and the found value is determined by R.equals
.
All Typescript definitions
pathEq(pathToSearch: Path, target: any, input: any): boolean;
pathEq(pathToSearch: Path, target: any): (input: any) => boolean;
pathEq(pathToSearch: Path): (target: any) => (input: any) => boolean;
R.pathEq source
import { curry } from './curry.js'
import { equals } from './equals.js'
import { path } from './path.js'
function pathEqFn(
pathToSearch, target, input
){
return equals(path(pathToSearch, input), target)
}
export const pathEq = curry(pathEqFn)
Tests
import { pathEq } from './pathEq.js'
test('when true', () => {
const path = 'a.b'
const obj = { a : { b : { c : 1 } } }
const target = { c : 1 }
expect(pathEq(
path, target, obj
)).toBeTrue()
})
test('when false', () => {
const path = 'a.b'
const obj = { a : { b : 1 } }
const target = 2
expect(pathEq(path, target)(obj)).toBeFalse()
})
test('when wrong path', () => {
const path = 'foo.bar'
const obj = { a : { b : 1 } }
const target = 2
expect(pathEq(
path, target, obj
)).toBeFalse()
})
Typescript test
import {pathEq} from 'rambda'
describe('R.pathEq', () => {
it('with string path', () => {
const pathToSearch = 'a.b.c'
const input = {a: {b: {c: 1}}}
const target = {c: 1}
const result = pathEq(pathToSearch, input, target)
const curriedResult = pathEq(pathToSearch, input, target)
result
curriedResult
})
it('with array path', () => {
const pathToSearch = ['a', 'b', 'c']
const input = {a: {b: {c: 1}}}
const target = {c: 1}
const result = pathEq(pathToSearch, input, target)
const curriedResult = pathEq(pathToSearch, input, target)
result
curriedResult
})
})
describe('with ramda specs', () => {
const testPath = ['x', 0, 'y']
const testObj = {
x: [
{y: 2, z: 3},
{y: 4, z: 5},
],
}
const result1 = pathEq(testPath, 2, testObj)
const result2 = pathEq(testPath, 2)(testObj)
const result3 = pathEq(testPath)(2)(testObj)
result1
result2
result3
})
pathOr
pathOr<T>(defaultValue: T, pathToSearch: Path, obj: any): T
It reads obj
input and returns either R.path(pathToSearch, Record<string, unknown>)
result or defaultValue
input.
All Typescript definitions
pathOr<T>(defaultValue: T, pathToSearch: Path, obj: any): T;
pathOr<T>(defaultValue: T, pathToSearch: Path): (obj: any) => T;
pathOr<T>(defaultValue: T): (pathToSearch: Path) => (obj: any) => T;
R.pathOr source
import { curry } from './curry.js'
import { defaultTo } from './defaultTo.js'
import { path } from './path.js'
function pathOrFn(
defaultValue, pathInput, obj
){
return defaultTo(defaultValue, path(pathInput, obj))
}
export const pathOr = curry(pathOrFn)
Tests
import { pathOr } from './pathOr.js'
test('with undefined', () => {
const result = pathOr(
'foo', 'x.y', { x : { y : 1 } }
)
expect(result).toEqual(1)
})
test('with null', () => {
const result = pathOr(
'foo', 'x.y', null
)
expect(result).toEqual('foo')
})
test('with NaN', () => {
const result = pathOr(
'foo', 'x.y', NaN
)
expect(result).toEqual('foo')
})
test('curry case (x)(y)(z)', () => {
const result = pathOr('foo')('x.y.z')({ x : { y : { a : 1 } } })
expect(result).toEqual('foo')
})
test('curry case (x)(y,z)', () => {
const result = pathOr('foo', 'x.y.z')({ x : { y : { a : 1 } } })
expect(result).toEqual('foo')
})
test('curry case (x,y)(z)', () => {
const result = pathOr('foo')('x.y.z', { x : { y : { a : 1 } } })
expect(result).toEqual('foo')
})
Typescript test
import {pathOr} from 'rambda'
describe('R.pathOr', () => {
it('with string path', () => {
const x = pathOr<string>('foo', 'x.y', {x: {y: 'bar'}})
x
})
it('with array path', () => {
const x = pathOr<string>('foo', ['x', 'y'], {x: {y: 'bar'}})
x
})
it('without passing type looks bad', () => {
const x = pathOr('foo', 'x.y', {x: {y: 'bar'}})
x
})
it('curried', () => {
const x = pathOr<string>('foo', 'x.y')({x: {y: 'bar'}})
x
})
})
paths
paths<Input, T>(pathsToSearch: Path[], obj: Input): (T | undefined)[]
It loops over members of pathsToSearch
as singlePath
and returns the array produced by R.path(singlePath, Record<string, unknown>)
.
Because it calls R.path
, then singlePath
can be either string or a list.
All Typescript definitions
paths<Input, T>(pathsToSearch: Path[], obj: Input): (T | undefined)[];
paths<Input, T>(pathsToSearch: Path[]): (obj: Input) => (T | undefined)[];
paths<T>(pathsToSearch: Path[], obj: any): (T | undefined)[];
paths<T>(pathsToSearch: Path[]): (obj: any) => (T | undefined)[];
R.paths source
import { path } from './path.js'
export function paths(pathsToSearch, obj){
if (arguments.length === 1){
return _obj => paths(pathsToSearch, _obj)
}
return pathsToSearch.map(singlePath => path(singlePath, obj))
}
Tests
import { paths } from './paths.js'
const obj = {
a : {
b : {
c : 1,
d : 2,
},
},
p : [ { q : 3 } ],
x : {
y : 'FOO',
z : [ [ {} ] ],
},
}
test('with string path + curry', () => {
const pathsInput = [ 'a.b.d', 'p.q' ]
const expected = [ 2, undefined ]
const result = paths(pathsInput, obj)
const curriedResult = paths(pathsInput)(obj)
expect(result).toEqual(expected)
expect(curriedResult).toEqual(expected)
})
test('with array path', () => {
const result = paths([
[ 'a', 'b', 'c' ],
[ 'x', 'y' ],
],
obj)
expect(result).toEqual([ 1, 'FOO' ])
})
test('takes a paths that contains indices into arrays', () => {
expect(paths([
[ 'p', 0, 'q' ],
[ 'x', 'z', 0, 0 ],
],
obj)).toEqual([ 3, {} ])
expect(paths([
[ 'p', 0, 'q' ],
[ 'x', 'z', 2, 1 ],
],
obj)).toEqual([ 3, undefined ])
})
test('gets a deep property\'s value from objects', () => {
expect(paths([ [ 'a', 'b' ] ], obj)).toEqual([ obj.a.b ])
expect(paths([ [ 'p', 0 ] ], obj)).toEqual([ obj.p[ 0 ] ])
})
test('returns undefined for items not found', () => {
expect(paths([ [ 'a', 'x', 'y' ] ], obj)).toEqual([ undefined ])
expect(paths([ [ 'p', 2 ] ], obj)).toEqual([ undefined ])
})
Typescript test
import {paths} from 'rambda'
interface Input {
a: number
b: number
c: number
}
const input: Input = {a: 1, b: 2, c: 3}
describe('R.paths', () => {
it('with dot notation', () => {
const result = paths<number>(['a.b.c', 'foo.bar'], input)
result
})
it('without type', () => {
const result = paths(['a.b.c', 'foo.bar'], input)
result
})
it('with array as path', () => {
const result = paths<number>([['a', 'b', 'c'], ['foo.bar']], input)
result
})
it('curried', () => {
const result = paths<number>([['a', 'b', 'c'], ['foo.bar']])(input)
result
})
})
pick
pick<T, K extends string | number | symbol>(propsToPick: K[], input: T): Pick<T, Exclude<keyof T, Exclude<keyof T, K>>>
It returns a partial copy of an input
containing only propsToPick
properties.
input
can be either an object or an array.
String anotation of propsToPick
is one of the differences between Rambda
and Ramda
.
All Typescript definitions
pick<T, K extends string | number | symbol>(propsToPick: K[], input: T): Pick<T, Exclude<keyof T, Exclude<keyof T, K>>>;
pick<K extends string | number | symbol>(propsToPick: K[]): <T>(input: T) => Pick<T, Exclude<keyof T, Exclude<keyof T, K>>>;
pick<T, U>(propsToPick: string, input: T): U;
pick<T, U>(propsToPick: string): (input: T) => U;
pick<T>(propsToPick: string, input: object): T;
pick<T>(propsToPick: string): (input: object) => T;
R.pick source
import { createPath } from './_internals/createPath.js'
export function pick(propsToPick, input){
if (arguments.length === 1) return _input => pick(propsToPick, _input)
if (input === null || input === undefined){
return undefined
}
const keys = createPath(propsToPick, ',')
const willReturn = {}
let counter = 0
while (counter < keys.length){
if (keys[ counter ] in input){
willReturn[ keys[ counter ] ] = input[ keys[ counter ] ]
}
counter++
}
return willReturn
}
Tests
import { pick } from './pick.js'
const obj = {
a : 1,
b : 2,
c : 3,
}
test('props to pick is a string', () => {
const result = pick('a,c', obj)
const resultCurry = pick('a,c')(obj)
const expectedResult = {
a : 1,
c : 3,
}
expect(result).toEqual(expectedResult)
expect(resultCurry).toEqual(expectedResult)
})
test('when prop is missing', () => {
const result = pick('a,d,f', obj)
expect(result).toEqual({ a : 1 })
})
test('with list indexes as props', () => {
const list = [ 1, 2, 3 ]
const expected = {
0 : 1,
2 : 3,
}
expect(pick([ 0, 2, 3 ], list)).toEqual(expected)
expect(pick('0,2,3', list)).toEqual(expected)
})
test('props to pick is an array', () => {
expect(pick([ 'a', 'c' ])({
a : 'foo',
b : 'bar',
c : 'baz',
})).toEqual({
a : 'foo',
c : 'baz',
})
expect(pick([ 'a', 'd', 'e', 'f' ])({
a : 'foo',
b : 'bar',
c : 'baz',
})).toEqual({ a : 'foo' })
expect(pick('a,d,e,f')(null)).toEqual(undefined)
})
test('works with list as input and number as props - props to pick is an array', () => {
const result = pick([ 1, 2 ], [ 'a', 'b', 'c', 'd' ])
expect(result).toEqual({
1 : 'b',
2 : 'c',
})
})
test('works with list as input and number as props - props to pick is a string', () => {
const result = pick('1,2', [ 'a', 'b', 'c', 'd' ])
expect(result).toEqual({
1 : 'b',
2 : 'c',
})
})
test('with symbol', () => {
const symbolProp = Symbol('s')
expect(pick([ symbolProp ], { [ symbolProp ] : 'a' })).toMatchInlineSnapshot(`
Object {
Symbol(s): "a",
}
`)
})
Typescript test
import {pick} from 'rambda'
const input = {a: 'foo', b: 2, c: 3, d: 4}
describe('R.pick with array as props input', () => {
it('without passing type', () => {
const result = pick(['a', 'c'], input)
result.a
result.c
})
})
describe('R.pick with string as props input', () => {
interface Input {
a: string
b: number
c: number
d: number
}
interface Output {
a: string
c: number
}
it('explicitly declare output', () => {
const result = pick<Output>('a,c', input)
result
result.a
result.c
const curriedResult = pick<Output>('a,c')(input)
curriedResult.a
})
it('explicitly declare input and output', () => {
const result = pick<Input, Output>('a,c', input)
result
result.a
const curriedResult = pick<Input, Output>('a,c')(input)
curriedResult.a
})
it('without passing type', () => {
const result = pick('a,c', input)
result
})
})
Rambda is fastest. Ramda is 19.07% slower and Lodash is 80.2% slower
const R = require('../../dist/rambda.js')
const obj = {
a : 'foo',
b : 'bar',
c : 'baz',
}
const pickInput = [ 'a', 'c' ]
const pick = [
{
label : 'Rambda',
fn : () => {
R.pick(pickInput, obj)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.pick(pickInput, obj)
},
},
{
label : 'Lodash',
fn : () => {
_.pick(obj, pickInput)
},
},
]
pickAll
pickAll<T, U>(propsToPick: string[], input: T): U
Same as R.pick
but it won't skip the missing props, i.e. it will assign them to undefined
.
All Typescript definitions
pickAll<T, U>(propsToPick: string[], input: T): U;
pickAll<T, U>(propsToPick: string[]): (input: T) => U;
pickAll<T, U>(propsToPick: string, input: T): U;
pickAll<T, U>(propsToPick: string): (input: T) => U;
R.pickAll source
import { createPath } from './_internals/createPath.js'
export function pickAll(propsToPick, obj){
if (arguments.length === 1) return _obj => pickAll(propsToPick, _obj)
if (obj === null || obj === undefined){
return undefined
}
const keysValue = createPath(propsToPick, ',')
const willReturn = {}
let counter = 0
while (counter < keysValue.length){
if (keysValue[ counter ] in obj){
willReturn[ keysValue[ counter ] ] = obj[ keysValue[ counter ] ]
} else {
willReturn[ keysValue[ counter ] ] = undefined
}
counter++
}
return willReturn
}
Tests
import { pickAll } from './pickAll.js'
test('when input is undefined or null', () => {
expect(pickAll('a', null)).toBe(undefined)
expect(pickAll('a', undefined)).toBe(undefined)
})
test('with string as condition', () => {
const obj = {
a : 1,
b : 2,
c : 3,
}
const result = pickAll('a,c', obj)
const resultCurry = pickAll('a,c')(obj)
const expectedResult = {
a : 1,
b : undefined,
c : 3,
}
expect(result).toEqual(expectedResult)
expect(resultCurry).toEqual(expectedResult)
})
test('with array as condition', () => {
expect(pickAll([ 'a', 'b', 'c' ], {
a : 'foo',
c : 'baz',
})).toEqual({
a : 'foo',
b : undefined,
c : 'baz',
})
})
Typescript test
import {pickAll} from 'rambda'
interface Input {
a: string
b: number
c: number
d: number
}
interface Output {
a?: string
c?: number
}
const input = {a: 'foo', b: 2, c: 3, d: 4}
describe('R.pickAll with array as props input', () => {
it('without passing type', () => {
const result = pickAll(['a', 'c'], input)
result
})
it('without passing type + curry', () => {
const result = pickAll(['a', 'c'])(input)
result
})
it('explicitly passing types', () => {
const result = pickAll<Input, Output>(['a', 'c'], input)
result.a
result.c
})
it('explicitly passing types + curry', () => {
const result = pickAll<Input, Output>(['a', 'c'])(input)
result.a
result.c
})
})
describe('R.pickAll with string as props input', () => {
it('without passing type', () => {
const result = pickAll('a,c', input)
result
})
it('without passing type + curry', () => {
const result = pickAll('a,c')(input)
result
})
it('explicitly passing types', () => {
const result = pickAll<Input, Output>('a,c', input)
result.a
result.c
})
it('explicitly passing types + curry', () => {
const result = pickAll<Input, Output>('a,c')(input)
result.a
result.c
})
})
pipe
It performs left-to-right function composition.
pluck
pluck<K extends keyof T, T>(property: K, list: T[]): T[K][]
It returns list of the values of property
taken from the all objects inside list
.
All Typescript definitions
pluck<K extends keyof T, T>(property: K, list: T[]): T[K][];
pluck<T>(property: number, list: { [k: number]: T }[]): T[];
pluck<P extends string>(property: P): <T>(list: Record<P, T>[]) => T[];
pluck(property: number): <T>(list: { [k: number]: T }[]) => T[];
R.pluck source
import { map } from './map.js'
export function pluck(property, list){
if (arguments.length === 1) return _list => pluck(property, _list)
const willReturn = []
map(x => {
if (x[ property ] !== undefined){
willReturn.push(x[ property ])
}
}, list)
return willReturn
}
Tests
import { pluck } from './pluck.js'
test('happy', () => {
expect(pluck('a')([ { a : 1 }, { a : 2 }, { b : 1 } ])).toEqual([ 1, 2 ])
})
test('with number', () => {
const input = [
[ 1, 2 ],
[ 3, 4 ],
]
expect(pluck(0, input)).toEqual([ 1, 3 ])
})
Typescript test
import {pluck} from 'rambda'
describe('R.pluck', () => {
it('with object', () => {
interface ListMember {
a: number
b: string
}
const input: ListMember[] = [
{a: 1, b: 'foo'},
{a: 2, b: 'bar'},
]
const resultA = pluck('a', input)
const resultB = pluck('b')(input)
resultA
resultB
})
it('with array', () => {
const input = [
[1, 2],
[3, 4],
[5, 6],
]
const result = pluck(0, input)
const resultCurry = pluck(0)(input)
result
resultCurry
})
})
prepend
prepend<T>(x: T, input: T[]): T[]
It adds element x
at the beginning of list
.
All Typescript definitions
prepend<T>(x: T, input: T[]): T[];
prepend<T>(x: T): (input: T[]) => T[];
R.prepend source
export function prepend(x, input){
if (arguments.length === 1) return _input => prepend(x, _input)
if (typeof input === 'string') return [ x ].concat(input.split(''))
return [ x ].concat(input)
}
Tests
import { prepend } from './prepend.js'
test('happy', () => {
expect(prepend('yes', [ 'foo', 'bar', 'baz' ])).toEqual([
'yes',
'foo',
'bar',
'baz',
])
})
test('with empty list', () => {
expect(prepend('foo')([])).toEqual([ 'foo' ])
})
test('with string instead of array', () => {
expect(prepend('foo')('bar')).toEqual([ 'foo', 'b', 'a', 'r' ])
})
Typescript test
import {prepend} from 'rambda'
const list = [1, 2, 3]
describe('R.prepend', () => {
it('happy', () => {
const result = prepend(4, list)
result
})
it('curried', () => {
const result = prepend(4)(list)
result
})
})
product
product(list: number[]): number
All Typescript definitions
product(list: number[]): number;
R.product source
import { multiply } from './multiply.js'
import { reduce } from './reduce.js'
export const product = reduce(multiply, 1)
Tests
import { product } from './product.js'
test('happy', () => {
expect(product([ 2, 3, 4 ])).toEqual(24)
})
test('bad input', () => {
expect(product([ null ])).toEqual(0)
expect(product([])).toEqual(1)
})
Typescript test
import {product} from 'rambda'
describe('R.product', () => {
it('happy', () => {
const result = product([1, 2, 3])
result
})
})
prop
prop<P extends keyof O, O>(propToFind: P, obj: O): O[P]
It returns the value of property propToFind
in obj
.
If there is no such property, it returns undefined
.
All Typescript definitions
prop<P extends keyof O, O>(propToFind: P, obj: O): O[P];
prop<P extends keyof O, O>(propToFind: P): (obj: O) => O[P];
prop<P extends string | number>(propToFind: P): <T>(obj: Record<P, T>) => T;
prop<P extends string | number, T>(propToFind: P): (obj: Record<P, T>) => T;
R.prop source
export function prop(propToFind, obj){
if (arguments.length === 1) return _obj => prop(propToFind, _obj)
if (!obj) return undefined
return obj[ propToFind ]
}
Tests
import { prop } from './prop.js'
test('prop', () => {
expect(prop('foo')({ foo : 'baz' })).toEqual('baz')
expect(prop('bar')({ foo : 'baz' })).toEqual(undefined)
expect(prop('bar')(null)).toEqual(undefined)
})
Typescript test
import {pipe, prop} from 'rambda'
describe('R.prop', () => {
const obj = {a: 1, b: 'foo'}
type Something = {a?: number, b?: string}
it('issue #553', () => {
const result = prop('e', {e: 'test1', d: 'test2'})
const curriedResult = prop<string>('e')({e: 'test1', d: 'test2'})
result
curriedResult
})
it('happy', () => {
const result = prop('a', obj)
result
})
it('curried', () => {
const result = prop('b')(obj)
result
})
it('curried with explicit object type', () => {
const result = prop<'a', Something>('a')(obj)
result
})
it('curried with implicit object type', () => {
const result = pipe((value) => value as Something, prop('b'))(obj)
result
})
it('curried with explicit result type', () => {
const result = prop<'b', string>('b')(obj)
result
})
})
describe('with number as prop', () => {
const list = [1, 2, 3]
const index = 1
it('happy', () => {
const result = prop(index, list)
result
})
it('curried require explicit type', () => {
const result = prop<number>(index)(list)
result
})
})
Rambda is faster than Ramda with 87.95%
const R = require('../../dist/rambda.js')
const obj = {
a : { c : 2 },
b : 1,
}
const propInput = 'b'
const prop = [
{
label : 'Rambda',
fn : () => {
R.prop(propInput, obj)
R.prop(propInput)(obj)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.prop(propInput, obj)
Ramda.prop(propInput)(obj)
},
},
]
propEq
propEq<K extends string | number>(propToFind: K, valueToMatch: any, obj: Record<K, any>): boolean
It returns true if obj
has property propToFind
and its value is equal to valueToMatch
.
All Typescript definitions
propEq<K extends string | number>(propToFind: K, valueToMatch: any, obj: Record<K, any>): boolean;
propEq<K extends string | number>(propToFind: K, valueToMatch: any): (obj: Record<K, any>) => boolean;
propEq<K extends string | number>(propToFind: K): {
(valueToMatch: any, obj: Record<K, any>): boolean;
(valueToMatch: any): (obj: Record<K, any>) => boolean;
};
R.propEq source
import { curry } from './curry.js'
function propEqFn(
propToFind, valueToMatch, obj
){
if (!obj) return false
return obj[ propToFind ] === valueToMatch
}
export const propEq = curry(propEqFn)
Tests
import { propEq } from './propEq.js'
test('happy', () => {
expect(propEq('foo', 'bar')({ foo : 'bar' })).toBeTrue()
expect(propEq('foo', 'bar')({ foo : 'baz' })).toBeFalse()
expect(propEq('foo')('bar')({ foo : 'baz' })).toBeFalse()
expect(propEq(
'foo', 'bar', null
)).toBeFalse()
})
Typescript test
import {propEq} from 'rambda'
const property = 'foo'
const numberProperty = 1
const value = 'bar'
const obj = {[property]: value}
const objWithNumberIndex = {[numberProperty]: value}
describe('R.propEq', () => {
it('happy', () => {
const result = propEq(property, value, obj)
result
})
it('number is property', () => {
const result = propEq(1, value, objWithNumberIndex)
result
})
it('with optional property', () => {
interface MyType {
optional?: string | number
}
const myObject: MyType = {}
const valueToFind = '1111'
propEq('optional', valueToFind, myObject)
propEq('optional', valueToFind, myObject)
})
it('imported from @types/ramda', () => {
interface A {
foo: string | null
}
const obj: A = {
foo: 'bar',
}
const value = ''
const result = propEq('foo', value)(obj)
result
propEq('bar', value)(obj)
})
})
Rambda is faster than Ramda with 91.92%
const R = require('../../dist/rambda.js')
const obj = {
a : { c : 2 },
b : 1,
}
const propInput = 'b'
const expected = { c : 2 }
const propEq = [
{
label : 'Rambda',
fn : () => {
R.propEq('a')(expected)(obj)
R.propEq('a', expected)(obj)
R.propEq(
'a', expected, obj
)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.propEq('a')(expected)(obj)
Ramda.propEq('a', expected)(obj)
Ramda.propEq(
'a', expected, obj
)
},
},
]
propIs
propIs<C extends (...args: any[]) => any, K extends keyof any>(type: C, name: K, obj: any): obj is Record<K, ReturnType<C>>
It returns true
if property
of obj
is from target
type.
All Typescript definitions
propIs<C extends (...args: any[]) => any, K extends keyof any>(type: C, name: K, obj: any): obj is Record<K, ReturnType<C>>;
propIs<C extends new (...args: any[]) => any, K extends keyof any>(type: C, name: K, obj: any): obj is Record<K, InstanceType<C>>;
propIs<C extends (...args: any[]) => any, K extends keyof any>(type: C, name: K): (obj: any) => obj is Record<K, ReturnType<C>>;
propIs<C extends new (...args: any[]) => any, K extends keyof any>(type: C, name: K): (obj: any) => obj is Record<K, InstanceType<C>>;
propIs<C extends (...args: any[]) => any>(type: C): {
<K extends keyof any>(name: K, obj: any): obj is Record<K, ReturnType<C>>;
<K extends keyof any>(name: K): (obj: any) => obj is Record<K, ReturnType<C>>;
};
propIs<C extends new (...args: any[]) => any>(type: C): {
<K extends keyof any>(name: K, obj: any): obj is Record<K, InstanceType<C>>;
<K extends keyof any>(name: K): (obj: any) => obj is Record<K, InstanceType<C>>;
};
R.propIs source
import { curry } from './curry.js'
import { is } from './is.js'
function propIsFn(
targetPrototype, property, obj
){
return is(targetPrototype, obj[ property ])
}
export const propIs = curry(propIsFn)
Tests
import { propIs } from './propIs.js'
const obj = {
a : 1,
b : 'foo',
}
test('when true', () => {
expect(propIs(
Number, 'a', obj
)).toBeTrue()
expect(propIs(
String, 'b', obj
)).toBeTrue()
})
test('when false', () => {
expect(propIs(
String, 'a', obj
)).toBeFalse()
expect(propIs(
Number, 'b', obj
)).toBeFalse()
})
Typescript test
import {propIs} from 'rambda'
const property = 'a'
const obj = {a: 1}
describe('R.propIs', () => {
it('happy', () => {
const result = propIs(Number, property, obj)
result
})
it('curried', () => {
const result = propIs(Number, property)(obj)
result
})
})
propOr
propOr<T, P extends string>(defaultValue: T, property: P, obj: Partial<Record<P, T>> | undefined): T
It returns either defaultValue
or the value of property
in obj
.
All Typescript definitions
propOr<T, P extends string>(defaultValue: T, property: P, obj: Partial<Record<P, T>> | undefined): T;
propOr<T, P extends string>(defaultValue: T, property: P): (obj: Partial<Record<P, T>> | undefined) => T;
propOr<T>(defaultValue: T): {
<P extends string>(property: P, obj: Partial<Record<P, T>> | undefined): T;
<P extends string>(property: P): (obj: Partial<Record<P, T>> | undefined) => T;
}
R.propOr source
import { curry } from './curry.js'
import { defaultTo } from './defaultTo.js'
function propOrFn(
defaultValue, property, obj
){
if (!obj) return defaultValue
return defaultTo(defaultValue, obj[ property ])
}
export const propOr = curry(propOrFn)
Tests
import { propOr } from './propOr.js'
test('propOr (result)', () => {
const obj = { a : 1 }
expect(propOr(
'default', 'a', obj
)).toEqual(1)
expect(propOr(
'default', 'notExist', obj
)).toEqual('default')
expect(propOr(
'default', 'notExist', null
)).toEqual('default')
})
test('propOr (currying)', () => {
const obj = { a : 1 }
expect(propOr('default')('a', obj)).toEqual(1)
expect(propOr('default', 'a')(obj)).toEqual(1)
expect(propOr('default')('notExist', obj)).toEqual('default')
expect(propOr('default', 'notExist')(obj)).toEqual('default')
})
Typescript test
import {propOr} from 'rambda'
const obj = {foo: 'bar'}
const property = 'foo'
const fallback = 'fallback'
describe('R.propOr', () => {
it('happy', () => {
const result = propOr(fallback, property, obj)
result
})
it('curry 1', () => {
const result = propOr(fallback)(property, obj)
result
})
it('curry 2', () => {
const result = propOr(fallback, property)(obj)
result
})
it('curry 3', () => {
const result = propOr(fallback)(property)(obj)
result
})
})
props
props<P extends string, T>(propsToPick: P[], obj: Record<P, T>): T[]
It takes list with properties propsToPick
and returns a list with property values in obj
.
All Typescript definitions
props<P extends string, T>(propsToPick: P[], obj: Record<P, T>): T[];
props<P extends string>(propsToPick: P[]): <T>(obj: Record<P, T>) => T[];
props<P extends string, T>(propsToPick: P[]): (obj: Record<P, T>) => T[];
R.props source
import { _isArray } from './_internals/_isArray.js'
import { mapArray } from './map.js'
export function props(propsToPick, obj){
if (arguments.length === 1){
return _obj => props(propsToPick, _obj)
}
if (!_isArray(propsToPick)){
throw new Error('propsToPick is not a list')
}
return mapArray(prop => obj[ prop ], propsToPick)
}
Tests
import { props } from './props.js'
const obj = {
a : 1,
b : 2,
}
const propsToPick = [ 'a', 'c' ]
test('happy', () => {
const result = props(propsToPick, obj)
expect(result).toEqual([ 1, undefined ])
})
test('curried', () => {
const result = props(propsToPick)(obj)
expect(result).toEqual([ 1, undefined ])
})
test('wrong input', () => {
expect(() => props(null)(obj)).toThrow()
})
Typescript test
import {props} from 'rambda'
const obj = {a: 1, b: 2}
describe('R.props', () => {
it('happy', () => {
const result = props(['a', 'b'], obj)
result
})
it('curried', () => {
const result = props(['a', 'b'])(obj)
result
})
})
propSatisfies
propSatisfies<T>(predicate: Predicate<T>, property: string, obj: Record<string, T>): boolean
It returns true
if the object property satisfies a given predicate.
All Typescript definitions
propSatisfies<T>(predicate: Predicate<T>, property: string, obj: Record<string, T>): boolean;
propSatisfies<T>(predicate: Predicate<T>, property: string): (obj: Record<string, T>) => boolean;
R.propSatisfies source
import { curry } from './curry.js'
import { prop } from './prop.js'
function propSatisfiesFn(
predicate, property, obj
){
return predicate(prop(property, obj))
}
export const propSatisfies = curry(propSatisfiesFn)
Tests
import {propSatisfies} from './propSatisfies'
const obj = {a: 1}
test('when true', () => {
expect(propSatisfies(x => x > 0, 'a', obj)).toBeTrue()
})
test('when false', () => {
expect(propSatisfies(x => x < 0, 'a')(obj)).toBeFalse()
})
Typescript test
import {propSatisfies} from 'rambda'
const obj = {a: 1}
describe('R.propSatisfies', () => {
it('happy', () => {
const result = propSatisfies(x => x > 0, 'a', obj)
result
})
it('curried requires explicit type', () => {
const result = propSatisfies<number>(x => x > 0, 'a')(obj)
result
})
})
range
range(startInclusive: number, endExclusive: number): number[]
It returns list of numbers between startInclusive
to endExclusive
markers.
All Typescript definitions
range(startInclusive: number, endExclusive: number): number[];
range(startInclusive: number): (endExclusive: number) => number[];
R.range source
export function range(start, end){
if (arguments.length === 1) return _end => range(start, _end)
if (Number.isNaN(Number(start)) || Number.isNaN(Number(end))){
throw new TypeError('Both arguments to range must be numbers')
}
if (end < start) return []
const len = end - start
const willReturn = Array(len)
for (let i = 0; i < len; i++){
willReturn[ i ] = start + i
}
return willReturn
}
Tests
import { range } from './range.js'
test('happy', () => {
expect(range(0, 10)).toEqual([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ])
})
test('end range is bigger than start range', () => {
expect(range(7, 3)).toEqual([])
expect(range(5, 5)).toEqual([])
})
test('with bad input', () => {
const throwMessage = 'Both arguments to range must be numbers'
expect(() => range('a', 6)).toThrowWithMessage(Error, throwMessage)
expect(() => range(6, 'z')).toThrowWithMessage(Error, throwMessage)
})
test('curry', () => {
expect(range(0)(10)).toEqual([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ])
})
Typescript test
import {range} from 'rambda'
describe('R.range', () => {
it('happy', () => {
const result = range(1, 4)
result
})
it('curried', () => {
const result = range(1)(4)
result
})
})
Rambda is fastest. Ramda is 61.8% slower and Lodash is 57.44% slower
const R = require('../../dist/rambda.js')
const start = 12
const end = 22
const range = [
{
label : 'Rambda',
fn : () => {
R.range(start, end)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.range(start, end)
},
},
{
label : 'Lodash',
fn : () => {
_.range(start, end)
},
},
]
reduce
reduce<T, TResult>(reducer: (prev: TResult, current: T, i: number) => TResult, initialValue: TResult, list: T[]): TResult
All Typescript definitions
reduce<T, TResult>(reducer: (prev: TResult, current: T, i: number) => TResult, initialValue: TResult, list: T[]): TResult;
reduce<T, TResult>(reducer: (prev: TResult, current: T) => TResult, initialValue: TResult, list: T[]): TResult;
reduce<T, TResult>(reducer: (prev: TResult, current: T, i?: number) => TResult): (initialValue: TResult, list: T[]) => TResult;
reduce<T, TResult>(reducer: (prev: TResult, current: T, i?: number) => TResult, initialValue: TResult): (list: T[]) => TResult;
R.reduce source
import { _isArray } from './_internals/_isArray.js'
import { _keys } from './_internals/_keys.js'
import { curry } from './curry.js'
export function reduceFn(
reducer, acc, list
){
if (!_isArray(list)){
throw new TypeError('reduce: list must be array or iterable')
}
let index = 0
const len = list.length
while (index < len){
acc = reducer(
acc, list[ index ], index, list
)
index++
}
return acc
}
export const reduce = curry(reduceFn)
Tests
import { reduce } from './reduce.js'
const reducer = (
prev, current, i
) => {
expect(i).toBeNumber()
return prev + current
}
const initialValue = 1
const list = [ 1, 2, 3 ]
const ERROR = 'reduce: list must be array or iterable'
test('happy', () => {
expect(reduce(
reducer, initialValue, list
)).toEqual(7)
})
test('with object as iterable', () => {
expect(() =>
reduce(
reducer, initialValue, {
a : 1,
b : 2,
}
)).toThrowWithMessage(TypeError, ERROR)
})
test('with undefined as iterable', () => {
expect(() => reduce(
reducer, 0, null
)).toThrowWithMessage(TypeError, ERROR)
})
Typescript test
import {reduce} from 'rambda'
describe('R.reduce', () => {
it('happy', () => {
const result = reduce<number, number>(
(acc, elem) => {
acc
elem
return acc + elem
},
1,
[1, 2, 3]
)
result
})
it('with two types', () => {
const result = reduce<number, string>(
(acc, elem) => {
acc
elem
return `${acc}${elem}`
},
'foo',
[1, 2, 3]
)
result
})
it('with index', () => {
const result = reduce<number, number>(
(acc, elem, i) => {
acc
elem
i
return acc + elem
},
1,
[1, 2, 3]
)
result
})
it('fallback', () => {
const result = reduce(
(acc, val) => {
acc
return acc + val
},
1,
[1, 2, 3]
)
result
})
it('fallback with index', () => {
const result = reduce(
(acc, val, i) => {
acc
i
return acc + val
},
1,
[1, 2, 3]
)
result
})
it('fallback with two types', () => {
const result = reduce(
(acc, val) => {
acc
return acc + val
},
'foo',
[1, 2, 3]
)
result
})
})
Lodash is fastest. Rambda is 60.48% slower and Ramda is 77.1% slower
const R = require('../../dist/rambda.js')
const fn = (acc, value) => acc + value
const holder = [ 1, 2, 3 ]
const acc = ''
const reduce = [
{
label : 'Rambda',
fn : () => {
R.reduce(
fn, acc, holder
)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.reduce(
fn, acc, holder
)
},
},
{
label : 'Lodash',
fn : () => {
_.reduce(
holder, fn, acc
)
},
},
]
reject
reject<T>(predicate: Predicate<T>, list: T[]): T[]
It has the opposite effect of R.filter
.
All Typescript definitions
reject<T>(predicate: Predicate<T>, list: T[]): T[];
reject<T>(predicate: Predicate<T>): (list: T[]) => T[];
reject<T>(predicate: Predicate<T>, obj: Dictionary<T>): Dictionary<T>;
reject<T, U>(predicate: Predicate<T>): (obj: Dictionary<T>) => Dictionary<T>;
R.reject source
import { filter } from './filter.js'
export function reject(predicate, list){
if (arguments.length === 1) return _list => reject(predicate, _list)
return filter(x => !predicate(x), list)
}
Tests
import { reject } from './reject.js'
const isOdd = n => n % 2 === 1
test('with array', () => {
expect(reject(isOdd)([ 1, 2, 3, 4 ])).toEqual([ 2, 4 ])
})
test('with object', () => {
const obj = {
a : 1,
b : 2,
c : 3,
d : 4,
}
expect(reject(isOdd, obj)).toEqual({
b : 2,
d : 4,
})
})
Typescript test
import {reject} from 'rambda'
describe('R.reject with array', () => {
it('happy', () => {
const result = reject(
x => {
x
return x > 1
},
[1, 2, 3]
)
result
})
it('curried require explicit type', () => {
const result = reject<number>(x => {
x
return x > 1
})([1, 2, 3])
result
})
})
describe('R.reject with objects', () => {
it('happy', () => {
const result = reject(
x => {
x
return x > 1
},
{a: 1, b: 2}
)
result
})
it('curried require dummy type', () => {
const result = reject<number, any>(x => {
return x > 1
})({a: 1, b: 2})
result
})
})
repeat
repeat<T>(x: T): (timesToRepeat: number) => T[]
All Typescript definitions
repeat<T>(x: T): (timesToRepeat: number) => T[];
repeat<T>(x: T, timesToRepeat: number): T[];
R.repeat source
export function repeat(x, timesToRepeat){
if (arguments.length === 1){
return _timesToRepeat => repeat(x, _timesToRepeat)
}
return Array(timesToRepeat).fill(x)
}
Tests
import { repeat } from './repeat.js'
test('repeat', () => {
expect(repeat('')(3)).toEqual([ '', '', '' ])
expect(repeat('foo', 3)).toEqual([ 'foo', 'foo', 'foo' ])
const obj = {}
const arr = repeat(obj, 3)
expect(arr).toEqual([ {}, {}, {} ])
expect(arr[ 0 ] === arr[ 1 ]).toBeTrue()
})
Typescript test
import {repeat} from 'rambda'
describe('R.repeat', () => {
it('happy', () => {
const result = repeat(4, 7)
result
})
it('curried', () => {
const result = repeat(4)(7)
result
})
})
Lodash is fastest. Rambda is 48.57% slower and Ramda is 68.98% slower
const R = require('../../dist/rambda.js')
const num = 10
const str = 'foo'
const repeat = [
{
label : 'Rambda',
fn : () => {
R.repeat(str, num)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.repeat(str, num)
},
},
{
label : 'Lodash',
fn : () => {
_.repeat(str, num)
},
},
]
replace
replace(strOrRegex: RegExp | string, replacer: string, str: string): string
It replaces strOrRegex
found in str
with replacer
.
All Typescript definitions
replace(strOrRegex: RegExp | string, replacer: string, str: string): string;
replace(strOrRegex: RegExp | string, replacer: string): (str: string) => string;
replace(strOrRegex: RegExp | string): (replacer: string) => (str: string) => string;
R.replace source
import { curry } from './curry.js'
function replaceFn(
pattern, replacer, str
){
return str.replace(pattern, replacer)
}
export const replace = curry(replaceFn)
Tests
import { replace } from './replace.js'
test('happy', () => {
expect(replace(
'foo', 'yes', 'foo bar baz'
)).toEqual('yes bar baz')
})
test('1', () => {
expect(replace(/\s/g)('|')('foo bar baz')).toEqual('foo|bar|baz')
})
test('2', () => {
expect(replace(/\s/g)('|', 'foo bar baz')).toEqual('foo|bar|baz')
})
test('3', () => {
expect(replace(/\s/g, '|')('foo bar baz')).toEqual('foo|bar|baz')
})
Typescript test
import {replace} from 'rambda'
const str = 'foo bar foo'
const replacer = 'bar'
describe('R.replace', () => {
it('happy', () => {
const result = replace(/foo/g, replacer, str)
result
})
it('with string as search pattern', () => {
const result = replace('foo', replacer, str)
result
})
})
describe('R.replace - curried', () => {
it('happy', () => {
const result = replace(/foo/g, replacer)(str)
result
})
it('with string as search pattern', () => {
const result = replace('foo', replacer)(str)
result
})
})
Lodash is fastest. Rambda is 33.45% slower and Ramda is 33.99% slower
const R = require('../../dist/rambda.js')
const replace = [
{
label : 'Rambda',
fn : () => {
R.replace(
/\s/g, '|', 'foo bar baz'
)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.replace(
/\s/g, '|', 'foo bar baz'
)
},
},
{
label : 'Lodash',
fn : () => {
_.replace(
'foo bar baz', /\s/g, '|'
)
},
},
]
reverse
reverse<T>(input: T[]): T[]
It returns a reversed copy of list or string input
.
All Typescript definitions
reverse<T>(input: T[]): T[];
reverse(input: string): string;
R.reverse source
export function reverse(listOrString){
if (typeof listOrString === 'string'){
return listOrString.split('').reverse()
.join('')
}
const clone = listOrString.slice()
return clone.reverse()
}
Tests
import { reverse } from './reverse.js'
test('happy', () => {
expect(reverse([ 1, 2, 3 ])).toEqual([ 3, 2, 1 ])
})
test('with string', () => {
expect(reverse('baz')).toEqual('zab')
})
test('it doesn\'t mutate', () => {
const arr = [ 1, 2, 3 ]
expect(reverse(arr)).toEqual([ 3, 2, 1 ])
expect(arr).toEqual([ 1, 2, 3 ])
})
Typescript test
import {reverse} from 'rambda'
const list = [1, 2, 3, 4, 5]
describe('R.reverse', () => {
it('happy', () => {
const result = reverse(list)
result
})
})
set
set<T, U>(lens: Lens, replacer: U, obj: T): T
It returns a copied Object or Array with modified lens
focus set to replacer
value.
All Typescript definitions
set<T, U>(lens: Lens, replacer: U, obj: T): T;
set<U>(lens: Lens, replacer: U): <T>(obj: T) => T;
set(lens: Lens): <T, U>(replacer: U, obj: T) => T;
R.set source
import { always } from './always.js'
import { curry } from './curry.js'
import { over } from './over.js'
function setFn(
lens, replacer, x
){
return over(
lens, always(replacer), x
)
}
export const set = curry(setFn)
Tests
import { assoc } from './assoc.js'
import { lens } from './lens.js'
import { lensIndex } from './lensIndex.js'
import { lensPath } from './lensPath.js'
import { prop } from './prop.js'
import { set } from './set.js'
const testObject = {
foo : 'bar',
baz : {
a : 'x',
b : 'y',
},
}
test('assoc lens', () => {
const assocLens = lens(prop('foo'), assoc('foo'))
const result = set(
assocLens, 'FOO', testObject
)
const expected = {
...testObject,
foo : 'FOO',
}
expect(result).toEqual(expected)
})
test('path lens', () => {
const pathLens = lensPath('baz.a')
const result = set(
pathLens, 'z', testObject
)
const expected = {
...testObject,
baz : {
a : 'z',
b : 'y',
},
}
expect(result).toEqual(expected)
})
test('index lens', () => {
const indexLens = lensIndex(0)
const result = set(
indexLens, 3, [ 1, 2 ]
)
expect(result).toEqual([ 3, 2 ])
})
Rambda is faster than Ramda with 50.35%
const R = require('../../dist/rambda.js')
const testObj = { a : 1 }
const last = [
{
label : 'Rambda',
fn : () => {
R.set(
R.lensProp('a'), 2, testObj
)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.set(
Ramda.lensProp('a'), 2, testObj
)
},
},
]
slice
slice(from: number, to: number, input: string): string
All Typescript definitions
slice(from: number, to: number, input: string): string;
slice<T>(from: number, to: number, input: T[]): T[];
slice(from: number, to: number): {
(input: string): string;
<T>(input: T[]): T[];
};
slice(from: number): {
(to: number, input: string): string;
<T>(to: number, input: T[]): T[];
};
R.slice source
import { curry } from './curry.js'
function sliceFn(
from, to, list
){
return list.slice(from, to)
}
export const slice = curry(sliceFn)
Tests
import { slice } from './slice.js'
test('slice', () => {
expect(slice(
1, 3, [ 'a', 'b', 'c', 'd' ]
)).toEqual([ 'b', 'c' ])
expect(slice(
1, Infinity, [ 'a', 'b', 'c', 'd' ]
)).toEqual([ 'b', 'c', 'd' ])
expect(slice(
0, -1, [ 'a', 'b', 'c', 'd' ]
)).toEqual([ 'a', 'b', 'c' ])
expect(slice(
-3, -1, [ 'a', 'b', 'c', 'd' ]
)).toEqual([ 'b', 'c' ])
expect(slice(
0, 3, 'ramda'
)).toEqual('ram')
})
Typescript test
import {slice} from 'rambda'
const list = [1, 2, 3, 4, 5]
describe('R.slice', () => {
it('happy', () => {
const result = slice(1, 3, list)
result
})
it('curried', () => {
const result = slice(1, 3)(list)
result
})
})
sort
sort<T>(sortFn: (a: T, b: T) => number, list: T[]): T[]
It returns copy of list
sorted by sortFn
function, where sortFn
needs to return only -1
, 0
or 1
.
All Typescript definitions
sort<T>(sortFn: (a: T, b: T) => number, list: T[]): T[];
sort<T>(sortFn: (a: T, b: T) => number): (list: T[]) => T[];
R.sort source
import { cloneList } from './_internals/cloneList.js'
export function sort(sortFn, list){
if (arguments.length === 1) return _list => sort(sortFn, _list)
return cloneList(list).sort(sortFn)
}
Tests
import { sort } from './sort.js'
const fn = (a, b) => a > b ? 1 : -1
test('sort', () => {
expect(sort((a, b) => a - b)([ 2, 3, 1 ])).toEqual([ 1, 2, 3 ])
})
test('it doesn\'t mutate', () => {
const list = [ 'foo', 'bar', 'baz' ]
expect(sort(fn, list)).toEqual([ 'bar', 'baz', 'foo' ])
expect(list[ 0 ]).toBe('foo')
expect(list[ 1 ]).toBe('bar')
expect(list[ 2 ]).toBe('baz')
})
Typescript test
import {sort} from 'rambda'
const list = [3, 0, 5, 2, 1]
function sortFn(a: number, b: number): number {
return a > b ? 1 : -1
}
describe('R.sort', () => {
it('happy', () => {
const result = sort(sortFn, list)
result
})
it('curried', () => {
const result = sort(sortFn)(list)
result
})
})
Rambda is faster than Ramda with 40.23%
const R = require('../../dist/rambda.js')
const list = [ 'foo', 'bar', 'baz' ]
const fn = (a, b) => a > b ? -1 : 1
const replace = [
{
label : 'Rambda',
fn : () => {
R.sort(fn, list)
R.sort(fn)(list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.sort(fn, list)
Ramda.sort(fn)(list)
},
},
]
sortBy
sortBy<T>(sortFn: (a: T) => Ord, list: T[]): T[]
It returns copy of list
sorted by sortFn
function, where sortFn
function returns a value to compare, i.e. it doesn't need to return only -1
, 0
or 1
.
All Typescript definitions
sortBy<T>(sortFn: (a: T) => Ord, list: T[]): T[];
sortBy<T>(sortFn: (a: T) => Ord): (list: T[]) => T[];
sortBy(sortFn: (a: any) => Ord): <T>(list: T[]) => T[];
R.sortBy source
import { cloneList } from './_internals/cloneList.js'
export function sortBy(sortFn, list){
if (arguments.length === 1) return _list => sortBy(sortFn, _list)
const clone = cloneList(list)
return clone.sort((a, b) => {
const aSortResult = sortFn(a)
const bSortResult = sortFn(b)
if (aSortResult === bSortResult) return 0
return aSortResult < bSortResult ? -1 : 1
})
}
Tests
import { compose } from './compose.js'
import { prop } from './prop.js'
import { sortBy } from './sortBy.js'
import { toLower } from './toLower.js'
test('happy', () => {
const input = [ { a : 2 }, { a : 1 }, { a : 1 }, { a : 3 } ]
const expected = [ { a : 1 }, { a : 1 }, { a : 2 }, { a : 3 } ]
const result = sortBy(x => x.a)(input)
expect(result).toEqual(expected)
})
test('with compose', () => {
const alice = {
name : 'ALICE',
age : 101,
}
const bob = {
name : 'Bob',
age : -10,
}
const clara = {
name : 'clara',
age : 314.159,
}
const people = [ clara, bob, alice ]
const sortByNameCaseInsensitive = sortBy(compose(toLower, prop('name')))
expect(sortByNameCaseInsensitive(people)).toEqual([ alice, bob, clara ])
})
Typescript test
import {sortBy, pipe} from 'rambda'
interface Input {
a: number
}
describe('R.sortBy', () => {
it('passing type to sort function', () => {
function fn(x: any): number {
return x.a
}
function fn2(x: Input): number {
return x.a
}
const input = [{a: 2}, {a: 1}, {a: 0}]
const result = sortBy(fn, input)
const curriedResult = sortBy(fn2)(input)
result
curriedResult
result[0].a
curriedResult[0].a
})
it('passing type to sort function and list', () => {
function fn(x: Input): number {
return x.a
}
const input: Input[] = [{a: 2}, {a: 1}, {a: 0}]
const result = sortBy(fn, input)
const curriedResult = sortBy(fn)(input)
result
curriedResult
result[0].a
})
it('with R.pipe', () => {
interface Obj {
value: number
}
const fn = pipe(sortBy<Obj>(x => x.value))
const result = fn([{value: 1}, {value: 2}])
result
})
})
Rambda is fastest. Ramda is 25.29% slower and Lodash is 56.88% slower
const R = require('../../dist/rambda.js')
const list = [ { a : 2 }, { a : 1 }, { a : 0 } ]
const fn = x => x.a
const replace = [
{
label : 'Rambda',
fn : () => {
R.sortBy(fn, list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.sortBy(fn, list)
},
},
{
label : 'Lodash',
fn : () => {
_.sortBy(list, fn)
},
},
]
split
split(separator: string | RegExp): (str: string) => string[]
Curried version of String.prototype.split
All Typescript definitions
split(separator: string | RegExp): (str: string) => string[];
split(separator: string | RegExp, str: string): string[];
R.split source
export function split(separator, str){
if (arguments.length === 1) return _str => split(separator, _str)
return str.split(separator)
}
Tests
import { split } from './split.js'
const str = 'foo|bar|baz'
const splitChar = '|'
const expected = [ 'foo', 'bar', 'baz' ]
test('happy', () => {
expect(split(splitChar, str)).toEqual(expected)
})
test('curried', () => {
expect(split(splitChar)(str)).toEqual(expected)
})
Typescript test
import {split} from 'rambda'
const str = 'foo|bar|baz'
const splitChar = '|'
describe('R.split', () => {
it('happy', () => {
const result = split(splitChar, str)
result
})
it('curried', () => {
const result = split(splitChar)(str)
result
})
})
Rambda is fastest. Ramda is 55.37% slower and Lodash is 17.64% slower
const R = require('../../dist/rambda.js')
const str = 'foo|bar|baz'
const sep = '|'
const split = [
{
label : 'Rambda',
fn : () => {
R.split(sep, str)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.split(sep, str)
},
},
{
label : 'Lodash',
fn : () => {
_.split(str, sep)
},
},
]
splitAt
splitAt<T>(index: number, input: T[]): [T[], T[]]
It splits string or array at a given index.
All Typescript definitions
splitAt<T>(index: number, input: T[]): [T[], T[]];
splitAt(index: number, input: string): [string, string];
splitAt(index: number): {
<T>(input: T[]): [T[], T[]];
(input: string): [string, string];
};
R.splitAt source
import { _isArray } from './_internals/_isArray.js'
import { drop } from './drop.js'
import { maybe } from './maybe.js'
import { take } from './take.js'
export function splitAt(index, input){
if (arguments.length === 1){
return _list => splitAt(index, _list)
}
if (!input) throw new TypeError(`Cannot read property 'slice' of ${ input }`)
if (!_isArray(input) && typeof input !== 'string') return [ [], [] ]
const correctIndex = maybe(
index < 0,
input.length + index < 0 ? 0 : input.length + index,
index
)
return [ take(correctIndex, input), drop(correctIndex, input) ]
}
Tests
import { splitAt as splitAtRamda } from 'ramda'
import { splitAt } from './splitAt.js'
const list = [ 1, 2, 3 ]
const str = 'foo bar'
test('with array', () => {
const result = splitAt(2, list)
expect(result).toEqual([ [ 1, 2 ], [ 3 ] ])
})
test('with array - index is negative number', () => {
const result = splitAt(-6, list)
expect(result).toEqual([ [], list ])
})
test('with array - index is out of scope', () => {
const result = splitAt(4, list)
expect(result).toEqual([ [ 1, 2, 3 ], [] ])
})
test('with string', () => {
const result = splitAt(4, str)
expect(result).toEqual([ 'foo ', 'bar' ])
})
test('with string - index is negative number', () => {
const result = splitAt(-2, str)
expect(result).toEqual([ 'foo b', 'ar' ])
})
test('with string - index is out of scope', () => {
const result = splitAt(10, str)
expect(result).toEqual([ str, '' ])
})
test('with array - index is out of scope', () => {
const result = splitAt(4)(list)
expect(result).toEqual([ [ 1, 2, 3 ], [] ])
})
const badInputs = [ 1, true, /foo/g, {} ]
const throwingBadInputs = [ null, undefined ]
test('with bad inputs', () => {
throwingBadInputs.forEach(badInput => {
expect(() => splitAt(1, badInput)).toThrowWithMessage(TypeError,
`Cannot read property 'slice' of ${ badInput }`)
expect(() => splitAtRamda(1, badInput)).toThrowWithMessage(TypeError,
`Cannot read properties of ${ badInput } (reading 'slice')`)
})
badInputs.forEach(badInput => {
const result = splitAt(1, badInput)
const ramdaResult = splitAtRamda(1, badInput)
expect(result).toEqual(ramdaResult)
})
})
Typescript test
import {splitAt} from 'ramda'
const index = 1
const str = 'foo'
const list = [1, 2, 3]
describe('R.splitAt with array', () => {
it('happy', () => {
const result = splitAt(index, list)
result
})
it('curried', () => {
const result = splitAt(index)(list)
result
})
})
describe('R.splitAt with string', () => {
it('happy', () => {
const result = splitAt(index, str)
result
})
it('curried', () => {
const result = splitAt(index)(str)
result
})
})
splitEvery
splitEvery<T>(sliceLength: number, input: T[]): (T[])[]
It splits input
into slices of sliceLength
.
All Typescript definitions
splitEvery<T>(sliceLength: number, input: T[]): (T[])[];
splitEvery(sliceLength: number, input: string): string[];
splitEvery(sliceLength: number): {
(input: string): string[];
<T>(input: T[]): (T[])[];
};
R.splitEvery source
export function splitEvery(sliceLength, listOrString){
if (arguments.length === 1){
return _listOrString => splitEvery(sliceLength, _listOrString)
}
if (sliceLength < 1){
throw new Error('First argument to splitEvery must be a positive integer')
}
const willReturn = []
let counter = 0
while (counter < listOrString.length){
willReturn.push(listOrString.slice(counter, counter += sliceLength))
}
return willReturn
}
Tests
import { splitEvery } from './splitEvery.js'
test('happy', () => {
expect(splitEvery(3, [ 1, 2, 3, 4, 5, 6, 7 ])).toEqual([
[ 1, 2, 3 ],
[ 4, 5, 6 ],
[ 7 ],
])
expect(splitEvery(3)('foobarbaz')).toEqual([ 'foo', 'bar', 'baz' ])
})
test('with bad input', () => {
expect(() =>
expect(splitEvery(0)('foo')).toEqual([ 'f', 'o', 'o' ])).toThrowWithMessage(Error,
'First argument to splitEvery must be a positive integer')
})
Typescript test
import {splitEvery} from 'rambda'
const list = [1, 2, 3, 4, 5, 6, 7]
describe('R.splitEvery', () => {
it('happy', () => {
const result = splitEvery(3, list)
result
})
it('curried', () => {
const result = splitEvery(3)(list)
result
})
})
Rambda is faster than Ramda with 71.98%
const R = require('../../dist/rambda.js')
const list = [ 1, 2, 3, 4, 5, 6, 7 ]
const splitEvery = [
{
label : 'Rambda',
fn : () => {
R.splitEvery(3, list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.splitEvery(3, list)
},
},
]
splitWhen
splitWhen<T, U>(predicate: Predicate<T>, list: U[]): (U[])[]
It splits list
to two arrays according to a predicate
function.
The first array contains all members of list
before predicate
returns true
.
All Typescript definitions
splitWhen<T, U>(predicate: Predicate<T>, list: U[]): (U[])[];
splitWhen<T>(predicate: Predicate<T>): <U>(list: U[]) => (U[])[];
R.splitWhen source
export function splitWhen(predicate, input){
if (arguments.length === 1){
return _input => splitWhen(predicate, _input)
}
if (!input)
throw new TypeError(`Cannot read property 'length' of ${ input }`)
const preFound = []
const postFound = []
let found = false
let counter = -1
while (counter++ < input.length - 1){
if (found){
postFound.push(input[ counter ])
} else if (predicate(input[ counter ])){
postFound.push(input[ counter ])
found = true
} else {
preFound.push(input[ counter ])
}
}
return [ preFound, postFound ]
}
Tests
import { splitWhen as splitWhenRamda } from 'ramda'
import { equals } from './equals.js'
import { splitWhen } from './splitWhen.js'
const list = [ 1, 2, 1, 2 ]
test('happy', () => {
const result = splitWhen(equals(2), list)
expect(result).toEqual([ [ 1 ], [ 2, 1, 2 ] ])
})
test('when predicate returns false', () => {
const result = splitWhen(equals(3))(list)
expect(result).toEqual([ list, [] ])
})
const badInputs = [ 1, true, /foo/g, {} ]
const throwingBadInputs = [ null, undefined ]
test('with bad inputs', () => {
throwingBadInputs.forEach(badInput => {
expect(() => splitWhen(equals(2), badInput)).toThrowWithMessage(TypeError,
`Cannot read property 'length' of ${ badInput }`)
expect(() => splitWhenRamda(equals(2), badInput)).toThrowWithMessage(TypeError,
`Cannot read properties of ${ badInput } (reading 'length')`)
})
badInputs.forEach(badInput => {
const result = splitWhen(equals(2), badInput)
const ramdaResult = splitWhenRamda(equals(2), badInput)
expect(result).toEqual(ramdaResult)
})
})
Typescript test
import {splitWhen} from 'rambda'
const list = [1, 2, 1, 2]
const predicate = (x: number) => x === 2
describe('R.splitWhen', () => {
it('happy', () => {
const result = splitWhen(predicate, list)
result
})
it('curried', () => {
const result = splitWhen(predicate)(list)
result
})
})
startsWith
startsWith(target: string, str: string): boolean
When iterable is a string, then it behaves as String.prototype.startsWith
.
When iterable is a list, then it uses R.equals to determine if the target list starts in the same way as the given target.
All Typescript definitions
startsWith(target: string, str: string): boolean;
startsWith(target: string): (str: string) => boolean;
startsWith<T>(target: T[], list: T[]): boolean;
startsWith<T>(target: T[]): (list: T[]) => boolean;
R.startsWith source
import { _isArray } from './_internals/_isArray.js'
import { equals } from './equals.js'
export function startsWith(target, iterable){
if (arguments.length === 1)
return _iterable => startsWith(target, _iterable)
if (typeof iterable === 'string'){
return iterable.startsWith(target)
}
if (!_isArray(target)) return false
let correct = true
const filtered = target.filter((x, index) => {
if (!correct) return false
const result = equals(x, iterable[ index ])
if (!result) correct = false
return result
})
return filtered.length === target.length
}
Tests
import { startsWith as startsWithRamda } from 'ramda'
import { compareCombinations } from './_internals/testUtils.js'
import { possibleIterables, possibleTargets } from './endsWith.spec.js'
import { startsWith } from './startsWith.js'
test('with string', () => {
expect(startsWith('foo', 'foo-bar')).toBeTrue()
expect(startsWith('baz')('foo-bar')).toBeFalse()
})
test('use R.equals with array', () => {
const list = [ { a : 1 }, { a : 2 }, { a : 3 } ]
expect(startsWith({ a : 1 }, list)).toBeFalse()
expect(startsWith([ { a : 1 } ], list)).toBeTrue()
expect(startsWith([ { a : 1 }, { a : 2 } ], list)).toBeTrue()
expect(startsWith(list, list)).toBeTrue()
expect(startsWith([ { a : 2 } ], list)).toBeFalse()
})
describe('brute force', () => {
compareCombinations({
fn : startsWith,
fnRamda : startsWithRamda,
firstInput : possibleTargets,
secondInput : possibleIterables,
callback : errorsCounters => {
expect(errorsCounters).toMatchInlineSnapshot(`
Object {
"ERRORS_MESSAGE_MISMATCH": 0,
"ERRORS_TYPE_MISMATCH": 0,
"RESULTS_MISMATCH": 0,
"SHOULD_NOT_THROW": 0,
"SHOULD_THROW": 0,
"TOTAL_TESTS": 32,
}
`)
},
})
})
Typescript test
import {startsWith} from 'rambda'
describe('R.startsWith - array as iterable', () => {
const target = [{a: 1}]
const iterable = [{a: 1}, {a: 2}]
it('happy', () => {
const result = startsWith(target, iterable)
result
})
it('curried', () => {
const result = startsWith(target)(iterable)
result
})
})
describe('R.startsWith - string as iterable', () => {
const target = 'foo'
const iterable = 'foo bar'
it('happy', () => {
const result = startsWith(target, iterable)
result
})
it('curried', () => {
const result = startsWith(target)(iterable)
result
})
})
subtract
Curried version of x - y
sum
sum(list: number[]): number
All Typescript definitions
sum(list: number[]): number;
R.sum source
export function sum(list){
return list.reduce((prev, current) => prev + current, 0)
}
Tests
import { sum } from './sum.js'
test('happy', () => {
expect(sum([ 1, 2, 3, 4, 5 ])).toBe(15)
})
symmetricDifference
symmetricDifference<T>(x: T[], y: T[]): T[]
It returns a merged list of x
and y
with all equal elements removed.
R.equals
is used to determine equality.
All Typescript definitions
symmetricDifference<T>(x: T[], y: T[]): T[];
symmetricDifference<T>(x: T[]): <T>(y: T[]) => T[];
R.symmetricDifference source
import { concat } from './concat.js'
import { filter } from './filter.js'
import { includes } from './includes.js'
export function symmetricDifference(x, y){
if (arguments.length === 1){
return _y => symmetricDifference(x, _y)
}
return concat(filter(value => !includes(value, y), x),
filter(value => !includes(value, x), y))
}
Tests
import { symmetricDifference } from './symmetricDifference.js'
test('symmetricDifference', () => {
const list1 = [ 1, 2, 3, 4 ]
const list2 = [ 3, 4, 5, 6 ]
expect(symmetricDifference(list1)(list2)).toEqual([ 1, 2, 5, 6 ])
expect(symmetricDifference([], [])).toEqual([])
})
test('symmetricDifference with objects', () => {
const list1 = [ { id : 1 }, { id : 2 }, { id : 3 }, { id : 4 } ]
const list2 = [ { id : 3 }, { id : 4 }, { id : 5 }, { id : 6 } ]
expect(symmetricDifference(list1)(list2)).toEqual([
{ id : 1 },
{ id : 2 },
{ id : 5 },
{ id : 6 },
])
})
Typescript test
import {symmetricDifference} from 'rambda'
describe('R.symmetricDifference', () => {
it('happy', () => {
const list1 = [1, 2, 3, 4]
const list2 = [3, 4, 5, 6]
const result = symmetricDifference(list1, list2)
result
})
it('curried', () => {
const list1 = [{id: 1}, {id: 2}, {id: 3}, {id: 4}]
const list2 = [{id: 3}, {id: 4}, {id: 5}, {id: 6}]
const result = symmetricDifference(list1)(list2)
result
})
})
T
T(): boolean
All Typescript definitions
T(): boolean;
R.T source
export function T(){
return true
}
tail
tail<T extends unknown[]>(input: T): T extends [any, ...infer U] ? U : [...T]
It returns all but the first element of input
.
All Typescript definitions
tail<T extends unknown[]>(input: T): T extends [any, ...infer U] ? U : [...T];
tail(input: string): string;
R.tail source
import { drop } from './drop.js'
export function tail(listOrString){
return drop(1, listOrString)
}
Tests
import { tail } from './tail.js'
test('tail', () => {
expect(tail([ 1, 2, 3 ])).toEqual([ 2, 3 ])
expect(tail([ 1, 2 ])).toEqual([ 2 ])
expect(tail([ 1 ])).toEqual([])
expect(tail([])).toEqual([])
expect(tail('abc')).toEqual('bc')
expect(tail('ab')).toEqual('b')
expect(tail('a')).toEqual('')
expect(tail('')).toEqual('')
})
Typescript test
import {tail} from 'rambda'
describe('R.tail', () => {
it('with string', () => {
const result = tail('foo')
result
})
it('with list - one type', () => {
const result = tail([1, 2, 3])
result
})
it('with list - mixed types', () => {
const result = tail(['foo', 'bar', 1, 2, 3])
result
})
})
take
take<T>(howMany: number, input: T[]): T[]
It returns the first howMany
elements of input
.
All Typescript definitions
take<T>(howMany: number, input: T[]): T[];
take(howMany: number, input: string): string;
take<T>(howMany: number): {
<T>(input: T[]): T[];
(input: string): string;
};
R.take source
import baseSlice from './_internals/baseSlice.js'
export function take(howMany, listOrString){
if (arguments.length === 1)
return _listOrString => take(howMany, _listOrString)
if (howMany < 0) return listOrString.slice()
if (typeof listOrString === 'string') return listOrString.slice(0, howMany)
return baseSlice(
listOrString, 0, howMany
)
}
Tests
import { take } from './take.js'
test('happy', () => {
const arr = [ 'foo', 'bar', 'baz' ]
expect(take(1, arr)).toEqual([ 'foo' ])
expect(arr).toEqual([ 'foo', 'bar', 'baz' ])
expect(take(2)([ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar' ])
expect(take(3, [ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar', 'baz' ])
expect(take(4, [ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar', 'baz' ])
expect(take(3)('rambda')).toEqual('ram')
})
test('with negative index', () => {
expect(take(-1, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])
expect(take(-Infinity, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])
})
test('with zero index', () => {
expect(take(0, [ 1, 2, 3 ])).toEqual([])
})
Typescript test
import {take} from 'rambda'
const list = [1, 2, 3, 4]
const str = 'foobar'
const howMany = 2
describe('R.take - array', () => {
it('happy', () => {
const result = take(howMany, list)
result
})
it('curried', () => {
const result = take(howMany)(list)
result
})
})
describe('R.take - string', () => {
it('happy', () => {
const result = take(howMany, str)
result
})
it('curried', () => {
const result = take(howMany)(str)
result
})
})
Rambda is fastest. Ramda is 91.96% slower and Lodash is 4.72% slower
const R = require('../../dist/rambda.js')
const list = [ 1, 2, 3, 4 ]
const num = 2
const take = [
{
label : 'Rambda',
fn : () => {
R.take(num, list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.take(num, list)
},
},
{
label : 'Lodash',
fn : () => {
_.take(list, num)
},
},
]
takeLast
takeLast<T>(howMany: number, input: T[]): T[]
It returns the last howMany
elements of input
.
All Typescript definitions
takeLast<T>(howMany: number, input: T[]): T[];
takeLast(howMany: number, input: string): string;
takeLast<T>(howMany: number): {
<T>(input: T[]): T[];
(input: string): string;
};
R.takeLast source
import baseSlice from './_internals/baseSlice.js'
export function takeLast(howMany, listOrString){
if (arguments.length === 1)
return _listOrString => takeLast(howMany, _listOrString)
const len = listOrString.length
if (howMany < 0) return listOrString.slice()
let numValue = howMany > len ? len : howMany
if (typeof listOrString === 'string')
return listOrString.slice(len - numValue)
numValue = len - numValue
return baseSlice(
listOrString, numValue, len
)
}
Tests
import { takeLast } from './takeLast.js'
test('with arrays', () => {
expect(takeLast(1, [ 'foo', 'bar', 'baz' ])).toEqual([ 'baz' ])
expect(takeLast(2)([ 'foo', 'bar', 'baz' ])).toEqual([ 'bar', 'baz' ])
expect(takeLast(3, [ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar', 'baz' ])
expect(takeLast(4, [ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar', 'baz' ])
expect(takeLast(10, [ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar', 'baz' ])
})
test('with strings', () => {
expect(takeLast(3, 'rambda')).toEqual('bda')
expect(takeLast(7, 'rambda')).toEqual('rambda')
})
test('with negative index', () => {
expect(takeLast(-1, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])
expect(takeLast(-Infinity, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])
})
Typescript test
import {takeLast} from 'rambda'
const list = [1, 2, 3, 4]
const str = 'foobar'
const howMany = 2
describe('R.takeLast - array', () => {
it('happy', () => {
const result = takeLast(howMany, list)
result
})
it('curried', () => {
const result = takeLast(howMany)(list)
result
})
})
describe('R.takeLast - string', () => {
it('happy', () => {
const result = takeLast(howMany, str)
result
})
it('curried', () => {
const result = takeLast(howMany)(str)
result
})
})
Rambda is fastest. Ramda is 93.39% slower and Lodash is 19.22% slower
const R = require('../../dist/rambda.js')
const list = [ 1, 2, 3, 4 ]
const num = 2
const takeLast = [
{
label : 'Rambda',
fn : () => {
R.takeLast(num, list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.takeLast(num, list)
},
},
{
label : 'Lodash',
fn : () => {
_.takeRight(list, num)
},
},
]
takeLastWhile
takeLastWhile(predicate: (x: string) => boolean, input: string): string
All Typescript definitions
takeLastWhile(predicate: (x: string) => boolean, input: string): string;
takeLastWhile(predicate: (x: string) => boolean): (input: string) => string;
takeLastWhile<T>(predicate: (x: T) => boolean, input: T[]): T[];
takeLastWhile<T>(predicate: (x: T) => boolean): <T>(input: T[]) => T[];
R.takeLastWhile source
import { _isArray } from './_internals/_isArray.js'
export function takeLastWhile(predicate, input){
if (arguments.length === 1){
return _input => takeLastWhile(predicate, _input)
}
if (input.length === 0) return input
let found = false
const toReturn = []
let counter = input.length
while (!found || counter === 0){
counter--
if (predicate(input[ counter ]) === false){
found = true
} else if (!found){
toReturn.push(input[ counter ])
}
}
return _isArray(input) ? toReturn.reverse() : toReturn.reverse().join('')
}
Tests
import { takeLastWhile } from './takeLastWhile.js'
const assert = require('assert')
const list = [ 1, 2, 3, 4 ]
test('happy', () => {
const predicate = x => x > 2
const result = takeLastWhile(predicate, list)
expect(result).toEqual([ 3, 4 ])
})
test('predicate is always true', () => {
const predicate = x => x > 0
const result = takeLastWhile(predicate)(list)
expect(result).toEqual(list)
})
test('predicate is always false', () => {
const predicate = x => x < 0
const result = takeLastWhile(predicate, list)
expect(result).toEqual([])
})
test('with string', () => {
const result = takeLastWhile(x => x !== 'F', 'FOOBAR')
expect(result).toEqual('OOBAR')
})
Typescript test
import {takeLastWhile} from 'rambda'
const list = [1, 2, 3]
const str = 'FOO'
describe('R.takeLastWhile', () => {
it('with array', () => {
const result = takeLastWhile(x => x > 1, list)
result
})
it('with array - curried', () => {
const result = takeLastWhile(x => x > 1, list)
result
})
it('with string', () => {
const result = takeLastWhile(x => x !== 'F', str)
result
})
it('with string - curried', () => {
const result = takeLastWhile(x => x !== 'F')(str)
result
})
})
takeWhile
tap
tap<T>(fn: (x: T) => void, input: T): T
It applies function fn
to input x
and returns x
.
One use case is debuging in the middle of R.compose
.
All Typescript definitions
tap<T>(fn: (x: T) => void, input: T): T;
tap<T>(fn: (x: T) => void): (input: T) => T;
R.tap source
export function tap(fn, x){
if (arguments.length === 1) return _x => tap(fn, _x)
fn(x)
return x
}
Tests
import { tap } from './tap.js'
test('tap', () => {
let a = 1
const sayX = x => a = x
expect(tap(sayX, 100)).toEqual(100)
expect(tap(sayX)(100)).toEqual(100)
expect(a).toEqual(100)
})
Typescript test
import {tap, pipe} from 'rambda'
describe('R.tap', () => {
it('happy', () => {
pipe(
tap(x => {
x
}),
(x: number[]) => x.length
)([1, 2])
})
})
test
test(regExpression: RegExp): (str: string) => boolean
It determines whether str
matches regExpression
.
All Typescript definitions
test(regExpression: RegExp): (str: string) => boolean;
test(regExpression: RegExp, str: string): boolean;
R.test source
export function test(pattern, str){
if (arguments.length === 1) return _str => test(pattern, _str)
if (typeof pattern === 'string'){
throw new TypeError(`‘test’ requires a value of type RegExp as its first argument; received "${ pattern }"`)
}
return str.search(pattern) !== -1
}
Tests
import { test as testMethod } from './test.js'
test('happy', () => {
expect(testMethod(/^x/, 'xyz')).toBeTrue()
expect(testMethod(/^y/)('xyz')).toBeFalse()
})
test('throws if first argument is not regex', () => {
expect(() => testMethod('foo', 'bar')).toThrowWithMessage(TypeError,
'‘test’ requires a value of type RegExp as its first argument; received "foo"')
})
Typescript test
import {test} from 'rambda'
const input = 'foo '
const regex = /foo/
describe('R.test', () => {
it('happy', () => {
const result = test(regex, input)
result
})
it('curried', () => {
const result = test(regex)(input)
result
})
})
Rambda is faster than Ramda with 82.34%
const R = require('../../dist/rambda.js')
const test = [
{
label : 'Rambda',
fn : () => {
R.test(/\s/g, 'x y z')
R.test(/\s/g)('x y z')
},
},
{
label : 'Ramda',
fn : () => {
Ramda.test(/\s/g, 'x y z')
Ramda.test(/\s/g)('x y z')
},
},
]
times
times<T>(fn: (i: number) => T, howMany: number): T[]
It returns the result of applying function fn
over members of range array.
The range array includes numbers between 0
and howMany
(exclusive).
All Typescript definitions
times<T>(fn: (i: number) => T, howMany: number): T[];
times<T>(fn: (i: number) => T): (howMany: number) => T[];
R.times source
import { map } from './map.js'
import { range } from './range.js'
export function times(fn, howMany){
if (arguments.length === 1) return _howMany => times(fn, _howMany)
if (!Number.isInteger(howMany) || howMany < 0){
throw new RangeError('n must be an integer')
}
return map(fn, range(0, howMany))
}
Tests
import assert from 'assert'
import { identity } from './identity.js'
import { times } from './times.js'
test('happy', () => {
const result = times(identity, 5)
expect(result).toEqual([ 0, 1, 2, 3, 4 ])
})
test('with bad input', () => {
assert.throws(() => {
times(3)('cheers!')
}, RangeError)
assert.throws(() => {
times(identity, -1)
}, RangeError)
})
test('curry', () => {
const result = times(identity)(5)
expect(result).toEqual([ 0, 1, 2, 3, 4 ])
})
Typescript test
import {times, identity} from 'rambda'
describe('R.times', () => {
it('happy', () => {
const result = times(identity, 5)
result
})
})
toLower
toLower<S extends string>(str: S): Lowercase<S>
All Typescript definitions
toLower<S extends string>(str: S): Lowercase<S>;
toLower(str: string): string;
R.toLower source
export function toLower(str){
return str.toLowerCase()
}
Tests
import { toLower } from './toLower.js'
test('toLower', () => {
expect(toLower('FOO|BAR|BAZ')).toEqual('foo|bar|baz')
})
toPairs
toPairs<O extends object, K extends Extract<keyof O, string | number>>(obj: O): Array<{ [key in K]: [`${key}`, O[key]] }[K]>
It transforms an object to a list.
All Typescript definitions
toPairs<O extends object, K extends Extract<keyof O, string | number>>(obj: O): Array<{ [key in K]: [`${key}`, O[key]] }[K]>;
toPairs<S>(obj: Record<string | number, S>): Array<[string, S]>;
R.toPairs source
export function toPairs(obj){
return Object.entries(obj)
}
Tests
import { toPairs } from './toPairs.js'
const obj = {
a : 1,
b : 2,
c : [ 3, 4 ],
}
const expected = [
[ 'a', 1 ],
[ 'b', 2 ],
[ 'c', [ 3, 4 ] ],
]
test('happy', () => {
expect(toPairs(obj)).toEqual(expected)
})
Typescript test
import {toPairs} from 'rambda'
const obj = {
a: 1,
b: 2,
c: [3, 4],
}
describe('R.toPairs', () => {
it('happy', () => {
const result = toPairs(obj)
result
})
})
toString
toString(x: unknown): string
All Typescript definitions
toString(x: unknown): string;
R.toString source
export function toString(x){
return x.toString()
}
Tests
import { toString } from './toString.js'
test('happy', () => {
expect(toString([ 1, 2, 3 ])).toEqual('1,2,3')
})
toUpper
toUpper<S extends string>(str: S): Uppercase<S>
All Typescript definitions
toUpper<S extends string>(str: S): Uppercase<S>;
toUpper(str: string): string;
R.toUpper source
export function toUpper(str){
return str.toUpperCase()
}
Tests
import { toUpper } from './toUpper.js'
test('toUpper', () => {
expect(toUpper('foo|bar|baz')).toEqual('FOO|BAR|BAZ')
})
transpose
transpose<T>(list: (T[])[]): (T[])[]
All Typescript definitions
transpose<T>(list: (T[])[]): (T[])[];
R.transpose source
import { _isArray } from './_internals/_isArray.js'
export function transpose(array){
return array.reduce((acc, el) => {
el.forEach((nestedEl, i) =>
_isArray(acc[ i ]) ? acc[ i ].push(nestedEl) : acc.push([ nestedEl ]))
return acc
}, [])
}
Tests
import { transpose } from './transpose.js'
test('happy', () => {
const input = [
[ 'a', 1 ],
[ 'b', 2 ],
[ 'c', 3 ],
]
expect(transpose(input)).toEqual([
[ 'a', 'b', 'c' ],
[ 1, 2, 3 ],
])
})
test('when rows are shorter', () => {
const actual = transpose([ [ 10, 11 ], [ 20 ], [], [ 30, 31, 32 ] ])
const expected = [ [ 10, 20, 30 ], [ 11, 31 ], [ 32 ] ]
expect(actual).toEqual(expected)
})
test('with empty array', () => {
expect(transpose([])).toEqual([])
})
test('array with falsy values', () => {
const actual = transpose([
[ true, false, undefined, null ],
[ null, undefined, false, true ],
])
const expected = [
[ true, null ],
[ false, undefined ],
[ undefined, false ],
[ null, true ],
]
expect(actual).toEqual(expected)
})
Typescript test
import {transpose} from 'rambda'
const input = [
['a', 1],
['b', 2],
['c', 3],
]
describe('R.transpose', () => {
it('happy', () => {
const result = transpose(input)
result
})
})
trim
trim(str: string): string
All Typescript definitions
trim(str: string): string;
R.trim source
export function trim(str){
return str.trim()
}
Tests
import { trim } from './trim.js'
test('trim', () => {
expect(trim(' foo ')).toEqual('foo')
})
tryCatch
It returns function that runs fn
in try/catch
block. If there was an error, then fallback
is used to return the result. Note that fn
can be value or asynchronous/synchronous function(unlike Ramda
where fallback can only be a synchronous function).
type
It accepts any input and it returns its type.
unapply
unapply<T = any>(fn: (args: any[]) => T): (...args: any[]) => T
It calls a function fn
with the list of values of the returned function.
R.unapply
is the opposite of R.apply
method.
All Typescript definitions
unapply<T = any>(fn: (args: any[]) => T): (...args: any[]) => T;
R.unapply source
export function unapply(fn){
return function (...args){
return fn.call(this, args)
}
}
Tests
import { apply } from './apply.js'
import { converge } from './converge.js'
import { identity } from './identity.js'
import { prop } from './prop.js'
import { sum } from './sum.js'
import { unapply } from './unapply.js'
test('happy', () => {
const fn = unapply(identity)
expect(fn(
1, 2, 3
)).toEqual([ 1, 2, 3 ])
expect(fn()).toEqual([])
})
test('returns a function which is always passed one argument', () => {
const fn = unapply(function (){
return arguments.length
})
expect(fn('x')).toEqual(1)
expect(fn('x', 'y')).toEqual(1)
expect(fn(
'x', 'y', 'z'
)).toEqual(1)
})
test('forwards arguments to decorated function as an array', () => {
const fn = unapply(xs => '[' + xs + ']')
expect(fn(2)).toEqual('[2]')
expect(fn(2, 4)).toEqual('[2,4]')
expect(fn(
2, 4, 6
)).toEqual('[2,4,6]')
})
test('returns a function with length 0', () => {
const fn = unapply(identity)
expect(fn.length).toEqual(0)
})
test('is the inverse of R.apply', () => {
let a, b, c, d, e, f, g, n
const rand = function (){
return Math.floor(200 * Math.random()) - 100
}
f = Math.max
g = unapply(apply(f))
n = 1
while (n <= 100){
a = rand()
b = rand()
c = rand()
d = rand()
e = rand()
expect(f(
a, b, c, d, e
)).toEqual(g(
a, b, c, d, e
))
n += 1
}
f = function (xs){
return '[' + xs + ']'
}
g = apply(unapply(f))
n = 1
while (n <= 100){
a = rand()
b = rand()
c = rand()
d = rand()
e = rand()
expect(f([ a, b, c, d, e ])).toEqual(g([ a, b, c, d, e ]))
n += 1
}
})
test('it works with converge', () => {
const fn = unapply(sum)
const convergeFn = converge(fn, [ prop('a'), prop('b'), prop('c') ])
const obj = {
a : 1337,
b : 42,
c : 1,
}
const expected = 1337 + 42 + 1
expect(convergeFn(obj)).toEqual(expected)
})
Typescript test
import {join, unapply, sum} from 'rambda'
describe('R.unapply', () => {
it('happy', () => {
const fn = unapply(sum)
fn(1, 2, 3)
})
it('joins a string', () => {
const fn = unapply(join(''))
fn('s', 't', 'r', 'i', 'n', 'g')
})
})
union
union<T>(x: T[], y: T[]): T[]
It takes two lists and return a new list containing a merger of both list with removed duplicates.
R.equals
is used to compare for duplication.
All Typescript definitions
union<T>(x: T[], y: T[]): T[];
union<T>(x: T[]): (y: T[]) => T[];
R.union source
import { cloneList } from './_internals/cloneList.js'
import { includes } from './includes.js'
export function union(x, y){
if (arguments.length === 1) return _y => union(x, _y)
const toReturn = cloneList(x)
y.forEach(yInstance => {
if (!includes(yInstance, x)) toReturn.push(yInstance)
})
return toReturn
}
Tests
import { union } from './union.js'
test('happy', () => {
expect(union([ 1, 2 ], [ 2, 3 ])).toEqual([ 1, 2, 3 ])
})
test('with list of objects', () => {
const list1 = [ { a : 1 }, { a : 2 } ]
const list2 = [ { a : 2 }, { a : 3 } ]
const result = union(list1)(list2)
})
Typescript test
import {union} from 'rambda'
describe('R.union', () => {
it('happy', () => {
const result = union([1, 2], [2, 3])
result
})
it('with array of objects - case 1', () => {
const list1 = [{a: 1}, {a: 2}]
const list2 = [{a: 2}, {a: 3}]
const result = union(list1, list2)
result
})
it('with array of objects - case 2', () => {
const list1 = [{a: 1, b: 1}, {a: 2}]
const list2 = [{a: 2}, {a: 3, b: 3}]
const result = union(list1, list2)
result[0].a
result[0].b
})
})
describe('R.union - curried', () => {
it('happy', () => {
const result = union([1, 2])([2, 3])
result
})
it('with array of objects - case 1', () => {
const list1 = [{a: 1}, {a: 2}]
const list2 = [{a: 2}, {a: 3}]
const result = union(list1)(list2)
result
})
it('with array of objects - case 2', () => {
const list1 = [{a: 1, b: 1}, {a: 2}]
const list2 = [{a: 2}, {a: 3, b: 3}]
const result = union(list1)(list2)
result[0].a
result[0].b
})
})
uniq
uniq<T>(list: T[]): T[]
It returns a new array containing only one copy of each element of list
.
R.equals
is used to determine equality.
All Typescript definitions
uniq<T>(list: T[]): T[];
R.uniq source
import { _Set } from './_internals/set.js'
export function uniq(list){
const set = new _Set()
const willReturn = []
list.forEach(item => {
if (set.checkUniqueness(item)){
willReturn.push(item)
}
})
return willReturn
}
Tests
import { uniq as uniqRamda } from 'ramda'
import { uniq } from './uniq.js'
test('happy', () => {
const list = [ 1, 2, 3, 3, 3, 1, 2, 0 ]
expect(uniq(list)).toEqual([ 1, 2, 3, 0 ])
})
test('with object', () => {
const list = [ { a : 1 }, { a : 2 }, { a : 1 }, { a : 2 } ]
expect(uniq(list)).toEqual([ { a : 1 }, { a : 2 } ])
})
test('with nested array', () => {
expect(uniq([ [ 42 ], [ 42 ] ])).toEqual([ [ 42 ] ])
})
test('with booleans', () => {
expect(uniq([ [ false ], [ false ], [ true ] ])).toEqual([ [ false ], [ true ] ])
})
test('with falsy values', () => {
expect(uniq([ undefined, null ])).toEqual([ undefined, null ])
})
test('can distinct between string and number', () => {
expect(uniq([ 1, '1' ])).toEqual([ 1, '1' ])
})
Typescript test
import {uniq} from 'rambda'
describe('R.uniq', () => {
it('happy', () => {
const result = uniq([1, 2, 3, 3, 3, 1, 2, 0])
result
})
})
Rambda is faster than Ramda with 86.73%
const R = require('../../dist/rambda.js')
const {
uniqListOfStrings,
uniqListOfBooleans,
uniqListOfNumbers,
uniqListOfLists,
uniqListOfObjects,
} = require('./_utils.js')
const limit = 100
const modes = [
uniqListOfStrings(limit),
uniqListOfBooleans(limit),
uniqListOfNumbers(limit),
uniqListOfLists(limit),
uniqListOfObjects(limit),
]
function applyBenchmark(fn, input){
fn(input)
}
const tests = [
{
label : 'Rambda',
fn : R.uniq,
},
{
label : 'Ramda',
fn : Ramda.uniq,
},
]
tests,
modes,
applyBenchmark,
}
uniqWith
uniqWith<T, U>(predicate: (x: T, y: T) => boolean, list: T[]): T[]
It returns a new array containing only one copy of each element in list
according to predicate
function.
This predicate should return true, if two elements are equal.
All Typescript definitions
uniqWith<T, U>(predicate: (x: T, y: T) => boolean, list: T[]): T[];
uniqWith<T, U>(predicate: (x: T, y: T) => boolean): (list: T[]) => T[];
R.uniqWith source
function includesWith(
predicate, target, list
){
let willReturn = false
let index = -1
while (++index < list.length && !willReturn){
const value = list[ index ]
if (predicate(target, value)){
willReturn = true
}
}
return willReturn
}
export function uniqWith(predicate, list){
if (arguments.length === 1) return _list => uniqWith(predicate, _list)
let index = -1
const willReturn = []
while (++index < list.length){
const value = list[ index ]
if (!includesWith(
predicate, value, willReturn
)){
willReturn.push(value)
}
}
return willReturn
}
Tests
import { uniqWith as uniqWithRamda } from 'ramda'
import { uniqWith } from './uniqWith.js'
const list = [ { a : 1 }, { a : 1 } ]
test('happy', () => {
const fn = (x, y) => x.a === y.a
const result = uniqWith(fn, list)
expect(result).toEqual([ { a : 1 } ])
})
test('with list of strings', () => {
const fn = (x, y) => x.length === y.length
const list = [ '0', '11', '222', '33', '4', '55' ]
const result = uniqWith(fn)(list)
const resultRamda = uniqWithRamda(fn, list)
expect(result).toEqual([ '0', '11', '222' ])
expect(resultRamda).toEqual([ '0', '11', '222' ])
})
Typescript test
import {uniqWith} from 'rambda'
describe('R.uniqWith', () => {
it('happy', () => {
const list = [{a: 1}, {a: 1}]
const fn = (x: any, y: any) => x.a === y.a
const result = uniqWith(fn, list)
result
})
})
Rambda is slower than Ramda with 13.67%
const R = require('../../dist/rambda.js')
const {
uniqListOfStrings,
uniqListOfBooleans,
uniqListOfNumbers,
uniqListOfLists,
uniqListOfObjects,
} = require('./_utils.js')
const limit = 100
const modes = [
[ uniqListOfStrings(limit), (x, y) => x.length === y.length ],
[ uniqListOfBooleans(limit), (x, y) => x === y ],
[ uniqListOfNumbers(limit), (x, y) => x > y ],
[ uniqListOfLists(limit), (x, y) => x.length === y.length ],
[
uniqListOfObjects(limit),
x => (x, y) => Object.keys(x).length === Object.keys(y).length,
],
]
function applyBenchmark(fn, input){
return fn(input[ 1 ], input[ 0 ])
}
const tests = [
{
label : 'Rambda',
fn : R.uniqWith,
},
{
label : 'Ramda',
fn : Ramda.uniqWith,
},
]
modes,
tests,
applyBenchmark,
}
unless
unless<T, U>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => U, x: T): T | U
The method returns function that will be called with argument input
.
If predicate(input)
returns false
, then the end result will be the outcome of whenFalse(input)
.
In the other case, the final output will be the input
itself.
All Typescript definitions
unless<T, U>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => U, x: T): T | U;
unless<T, U>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => U): (x: T) => T | U;
unless<T>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => T, x: T): T;
unless<T>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => T): (x: T) => T;
R.unless source
export function unless(predicate, whenFalse){
if (arguments.length === 1){
return _whenFalse => unless(predicate, _whenFalse)
}
return input => predicate(input) ? input : whenFalse(input)
}
Tests
import { inc } from './inc.js'
import { isNil } from './isNil.js'
import { unless } from './unless.js'
test('happy', () => {
const safeInc = unless(isNil, inc)
expect(safeInc(null)).toBeNull()
expect(safeInc(1)).toBe(2)
})
test('curried', () => {
const safeIncCurried = unless(isNil)(inc)
expect(safeIncCurried(null)).toBeNull()
})
Typescript test
import {unless, inc} from 'rambda'
describe('R.unless', () => {
it('happy', () => {
const fn = unless(x => x > 5, inc)
const result = fn(1)
result
})
it('with one explicit type', () => {
const result = unless(
x => {
x
return x > 5
},
x => {
x
return x + 1
},
1
)
result
})
it('with two different explicit types', () => {
const result = unless(
x => {
x
return x > 5
},
x => {
x
return `${x}-foo`
},
1
)
result
})
})
describe('R.unless - curried', () => {
it('happy', () => {
const fn = unless(x => x > 5, inc)
const result = fn(1)
result
})
it('with one explicit type', () => {
const fn = unless<number>(
x => {
x
return x > 5
},
x => {
x
return x + 1
}
)
const result = fn(1)
result
})
it('with two different explicit types', () => {
const fn = unless<number, string>(
x => {
x
return x > 5
},
x => {
x
return `${x}-foo`
}
)
const result = fn(1)
result
})
})
unwind
update
update<T>(index: number, newValue: T, list: T[]): T[]
It returns a copy of list
with updated element at index
with newValue
.
All Typescript definitions
update<T>(index: number, newValue: T, list: T[]): T[];
update<T>(index: number, newValue: T): (list: T[]) => T[];
R.update source
import { cloneList } from './_internals/cloneList.js'
import { curry } from './curry.js'
function updateFn(
index, newValue, list
){
const clone = cloneList(list)
if (index === -1) return clone.fill(newValue, index)
return clone.fill(
newValue, index, index + 1
)
}
export const update = curry(updateFn)
Tests
import { update } from './update.js'
const list = [ 1, 2, 3 ]
test('happy', () => {
const newValue = 8
const index = 1
const result = update(
index, newValue, list
)
const curriedResult = update(index, newValue)(list)
const tripleCurriedResult = update(index)(newValue)(list)
const expected = [ 1, 8, 3 ]
expect(result).toEqual(expected)
expect(curriedResult).toEqual(expected)
expect(tripleCurriedResult).toEqual(expected)
})
test('list has no such index', () => {
const newValue = 8
const index = 10
const result = update(
index, newValue, list
)
expect(result).toEqual(list)
})
test('with negative index', () => {
expect(update(
-1, 10, [ 1 ]
)).toEqual([ 10 ])
expect(update(
-1, 10, []
)).toEqual([])
expect(update(
-1, 10, list
)).toEqual([ 1, 2, 10 ])
expect(update(
-2, 10, list
)).toEqual([ 1, 10, 3 ])
expect(update(
-3, 10, list
)).toEqual([ 10, 2, 3 ])
})
Typescript test
import {update} from 'rambda'
describe('R.update', () => {
it('happy', () => {
const result = update(1, 0, [1, 2, 3])
result
})
})
Rambda is faster than Ramda with 52.35%
const R = require('../../dist/rambda.js')
const list = [ 0, 1, 2 ]
const index = 1
const replacer = 7
const update = [
{
label : 'Rambda',
fn : () => {
R.update(
replacer, index, list
)
R.update(replacer, index)(list)
R.update(replacer)(index)(list)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.update(
replacer, index, list
)
Ramda.update(replacer, index)(list)
Ramda.update(replacer)(index)(list)
},
},
]
values
values<T extends object, K extends keyof T>(obj: T): T[K][]
With correct input, this is nothing more than Object.values(Record<string, unknown>)
. If obj
is not an object, then it returns an empty array.
All Typescript definitions
values<T extends object, K extends keyof T>(obj: T): T[K][];
R.values source
import { type } from './type.js'
export function values(obj){
if (type(obj) !== 'Object') return []
return Object.values(obj)
}
Tests
import { values } from './values.js'
test('happy', () => {
expect(values({
a : 1,
b : 2,
c : 3,
})).toEqual([ 1, 2, 3 ])
})
test('with bad input', () => {
expect(values(null)).toEqual([])
expect(values(undefined)).toEqual([])
expect(values(55)).toEqual([])
expect(values('foo')).toEqual([])
expect(values(true)).toEqual([])
expect(values(false)).toEqual([])
expect(values(NaN)).toEqual([])
expect(values(Infinity)).toEqual([])
expect(values([])).toEqual([])
})
Typescript test
import {values} from 'rambda'
describe('R.values', () => {
it('happy', () => {
const result = values({
a: 1,
b: 2,
c: 3,
})
result
})
})
view
view<T, U>(lens: Lens): (target: T) => U
It returns the value of lens
focus over target
object.
All Typescript definitions
view<T, U>(lens: Lens): (target: T) => U;
view<T, U>(lens: Lens, target: T): U;
R.view source
const Const = x => ({
x,
map : fn => Const(x),
})
export function view(lens, target){
if (arguments.length === 1) return _target => view(lens, _target)
return lens(Const)(target).x
}
Tests
import { assoc } from './assoc.js'
import { lens } from './lens.js'
import { prop } from './prop.js'
import { view } from './view.js'
const testObject = { foo : 'Led Zeppelin' }
const assocLens = lens(prop('foo'), assoc('foo'))
test('happy', () => {
expect(view(assocLens, testObject)).toEqual('Led Zeppelin')
})
Typescript test
import {lens, view, assoc} from 'rambda'
interface Input {
foo: string
}
const testObject: Input = {
foo: 'Led Zeppelin',
}
const fooLens = lens<Input, string, string>((x: Input) => {
return x.foo
}, assoc('foo'))
describe('R.view', () => {
it('happt', () => {
const result = view<Input, string>(fooLens, testObject)
result
})
})
Rambda is faster than Ramda with 76.15%
const R = require('../../dist/rambda.js')
const testObj = { a : 1 }
const last = [
{
label : 'Rambda',
fn : () => {
R.view(R.lensProp('a'), testObj)
},
},
{
label : 'Ramda',
fn : () => {
Ramda.view(Ramda.lensProp('a'), testObj)
},
},
]
when
when<T, U>(predicate: (x: T) => boolean, whenTrueFn: (a: T) => U, input: T): T | U
All Typescript definitions
when<T, U>(predicate: (x: T) => boolean, whenTrueFn: (a: T) => U, input: T): T | U;
when<T, U>(predicate: (x: T) => boolean, whenTrueFn: (a: T) => U): (input: T) => T | U;
when<T, U>(predicate: (x: T) => boolean): ((whenTrueFn: (a: T) => U) => (input: T) => T | U);
R.when source
import { curry } from './curry.js'
function whenFn(
predicate, whenTrueFn, input
){
if (!predicate(input)) return input
return whenTrueFn(input)
}
export const when = curry(whenFn)
Tests
import { add } from './add.js'
import { when } from './when.js'
const predicate = x => typeof x === 'number'
test('happy', () => {
const fn = when(predicate, add(11))
expect(fn(11)).toBe(22)
expect(fn('foo')).toBe('foo')
})
Typescript test
import {when} from 'rambda'
const predicate = (x: number) => x > 2
const whenTrueFn = (x: number) => String(x)
describe('R.when', () => {
it('happy', () => {
const result = when(predicate, whenTrueFn, 1)
result
})
it('curry 1', () => {
const fn = when(predicate, whenTrueFn)
const result = fn(1)
result
})
it('curry 2 require explicit types', () => {
const fn = when<number, string>(predicate)(whenTrueFn)
const result = fn(1)
result
})
})
where
where<T, U>(conditions: T, input: U): boolean
It returns true
if all each property in conditions
returns true
when applied to corresponding property in input
object.
All Typescript definitions
where<T, U>(conditions: T, input: U): boolean;
where<T>(conditions: T): <U>(input: U) => boolean;
where<ObjFunc2, U>(conditions: ObjFunc2, input: U): boolean;
where<ObjFunc2>(conditions: ObjFunc2): <U>(input: U) => boolean;
R.where source
export function where(conditions, input){
if (input === undefined){
return _input => where(conditions, _input)
}
let flag = true
for (const prop in conditions){
const result = conditions[ prop ](input[ prop ])
if (flag && result === false){
flag = false
}
}
return flag
}
Tests
import {equals} from './equals.js'
import {where} from './where.js'
test('when true', () => {
const predicate = where({
a: equals('foo'),
b: equals('bar'),
})
expect(
predicate({
a: 'foo',
b: 'bar',
x: 11,
y: 19,
})
).toBeTrue()
})
test('when false', () => {
const predicate = where({
a: equals('foo'),
b: equals('baz'),
})
expect(
predicate({
a: 'foo',
b: 'bar',
x: 11,
y: 19,
})
).toBeFalse()
})
Typescript test
import {where, equals} from 'rambda'
describe('R.where', () => {
it('happy', () => {
const input = {
a: 'foo',
b: 'bar',
x: 11,
y: 19,
}
const conditions = {
a: equals('foo'),
b: equals('bar'),
}
const result = where(conditions, input)
const curriedResult = where(conditions)(input)
result
curriedResult
})
})
whereAny
Same as R.where
, but it will return true
if at least one condition check returns true
.
whereEq
whereEq<T, U>(condition: T, input: U): boolean
It will return true
if all of input
object fully or partially include rule
object.
R.equals
is used to determine equality.
All Typescript definitions
whereEq<T, U>(condition: T, input: U): boolean;
whereEq<T>(condition: T): <U>(input: U) => boolean;
R.whereEq source
import { equals } from './equals.js'
import { filter } from './filter.js'
export function whereEq(condition, input){
if (arguments.length === 1){
return _input => whereEq(condition, _input)
}
const result = filter((conditionValue, conditionProp) =>
equals(conditionValue, input[ conditionProp ]),
condition)
return Object.keys(result).length === Object.keys(condition).length
}
Tests
import { whereEq } from './whereEq.js'
test('when true', () => {
const condition = { a : 1 }
const input = {
a : 1,
b : 2,
}
const result = whereEq(condition, input)
const expectedResult = true
expect(result).toEqual(expectedResult)
})
test('when false', () => {
const condition = { a : 1 }
const input = { b : 2 }
const result = whereEq(condition, input)
const expectedResult = false
expect(result).toEqual(expectedResult)
})
test('with nested object', () => {
const condition = { a : { b : 1 } }
const input = {
a : { b : 1 },
c : 2,
}
const result = whereEq(condition)(input)
const expectedResult = true
expect(result).toEqual(expectedResult)
})
test('with wrong input', () => {
const condition = { a : { b : 1 } }
expect(() => whereEq(condition, null)).toThrowWithMessage(TypeError,
'Cannot read properties of null (reading \'a\')')
})
Typescript test
import {whereEq} from 'rambda'
describe('R.whereEq', () => {
it('happy', () => {
const result = whereEq({a: {b: 2}}, {b: 2})
const curriedResult = whereEq({a: {b: 2}})({b: 2})
result
curriedResult
})
})
without
without<T>(matchAgainst: T[], source: T[]): T[]
It will return a new array, based on all members of source
list that are not part of matchAgainst
list.
R.equals
is used to determine equality.
All Typescript definitions
without<T>(matchAgainst: T[], source: T[]): T[];
without<T>(matchAgainst: T[]): (source: T[]) => T[];
R.without source
import { _indexOf } from './equals.js'
import { reduce } from './reduce.js'
export function without(matchAgainst, source){
if (source === undefined){
return _source => without(matchAgainst, _source)
}
return reduce(
(prev, current) =>
_indexOf(current, matchAgainst) > -1 ? prev : prev.concat(current),
[],
source
)
}
Tests
import { without as withoutRamda } from 'ramda'
import { without } from './without.js'
test('should return a new list without values in the first argument', () => {
const itemsToOmit = [ 'A', 'B', 'C' ]
const collection = [ 'A', 'B', 'C', 'D', 'E', 'F' ]
expect(without(itemsToOmit, collection)).toEqual([ 'D', 'E', 'F' ])
expect(without(itemsToOmit)(collection)).toEqual([ 'D', 'E', 'F' ])
})
test('with list of objects', () => {
const itemsToOmit = [ { a : 1 }, { c : 3 } ]
const collection = [ { a : 1 }, { b : 2 }, { c : 3 }, { d : 4 } ]
const expected = [ { b : 2 }, { d : 4 } ]
expect(without(itemsToOmit, collection)).toEqual(expected)
expect(withoutRamda(itemsToOmit, collection)).toEqual(expected)
})
test('ramda accepts string as target input while rambda throws', () => {
expect(withoutRamda('0:1', [ '0', '0:1' ])).toEqual([])
expect(() => without('0:1', [ '0', '0:1' ])).toThrow()
expect(without([ '0:1' ], [ '0', '0:1' ])).toEqual([ '0' ])
})
test('ramda test', () => {
expect(without([ 1, 2 ])([ 1, 2, 1, 3, 4 ])).toEqual([ 3, 4 ])
})
Typescript test
import {without} from 'rambda'
const itemsToOmit = ['A', 'B', 'C']
const collection = ['A', 'B', 'C', 'D', 'E', 'F']
describe('R.without', () => {
it('happy', () => {
const result = without(itemsToOmit, collection)
result
})
it('curried', () => {
const result = without(itemsToOmit)(collection)
result
})
})
xor
xor(x: boolean, y: boolean): boolean
Logical XOR
All Typescript definitions
xor(x: boolean, y: boolean): boolean;
xor(y: boolean): (y: boolean) => boolean;
R.xor source
export function xor(a, b){
if (arguments.length === 1) return _b => xor(a, _b)
return Boolean(a) && !b || Boolean(b) && !a
}
Tests
import {xor} from './xor.js'
test('compares two values with exclusive or', () => {
expect(xor(true, true)).toBeFalse()
expect(xor(true, false)).toBeTrue()
expect(xor(false, true)).toBeTrue()
expect(xor(false, false)).toBeFalse()
})
test('when both values are truthy, it should return false', () => {
expect(xor(true, 'foo')).toBeFalse()
expect(xor(42, true)).toBeFalse()
expect(xor('foo', 42)).toBeFalse()
expect(xor({}, true)).toBeFalse()
expect(xor(true, [])).toBeFalse()
expect(xor([], {})).toBeFalse()
expect(xor(new Date(), true)).toBeFalse()
expect(xor(true, Infinity)).toBeFalse()
expect(xor(Infinity, new Date())).toBeFalse()
})
test('when both values are falsy, it should return false', () => {
expect(xor(null, false)).toBeFalse()
expect(xor(false, undefined)).toBeFalse()
expect(xor(undefined, null)).toBeFalse()
expect(xor(0, false)).toBeFalse()
expect(xor(false, NaN)).toBeFalse()
expect(xor(NaN, 0)).toBeFalse()
expect(xor('', false)).toBeFalse()
})
test('when one argument is truthy and the other is falsy, it should return true', () => {
expect(xor('foo', null)).toBeTrue()
expect(xor(null, 'foo')).toBeTrue()
expect(xor(undefined, 42)).toBeTrue()
expect(xor(42, undefined)).toBeTrue()
expect(xor(Infinity, NaN)).toBeTrue()
expect(xor(NaN, Infinity)).toBeTrue()
expect(xor({}, '')).toBeTrue()
expect(xor('', {})).toBeTrue()
expect(xor(new Date(), 0)).toBeTrue()
expect(xor(0, new Date())).toBeTrue()
expect(xor([], null)).toBeTrue()
expect(xor(undefined, [])).toBeTrue()
})
Typescript test
import {xor} from 'rambda'
describe('R.xor', () => {
it('happy', () => {
xor(true, false)
})
it('curry', () => {
xor(true)(false)
})
})
zip
zip<K, V>(x: K[], y: V[]): KeyValuePair<K, V>[]
It will return a new array containing tuples of equally positions items from both x
and y
lists.
The returned list will be truncated to match the length of the shortest supplied list.
All Typescript definitions
zip<K, V>(x: K[], y: V[]): KeyValuePair<K, V>[];
zip<K>(x: K[]): <V>(y: V[]) => KeyValuePair<K, V>[];
R.zip source
export function zip(left, right){
if (arguments.length === 1) return _right => zip(left, _right)
const result = []
const length = Math.min(left.length, right.length)
for (let i = 0; i < length; i++){
result[ i ] = [ left[ i ], right[ i ] ]
}
return result
}
Tests
import { zip } from './zip.js'
const array1 = [ 1, 2, 3 ]
const array2 = [ 'A', 'B', 'C' ]
test('should return an array', () => {
const actual = zip(array1)(array2)
expect(actual).toBeInstanceOf(Array)
})
test('should return and array or tuples', () => {
const expected = [
[ 1, 'A' ],
[ 2, 'B' ],
[ 3, 'C' ],
]
const actual = zip(array1, array2)
expect(actual).toEqual(expected)
})
test('should truncate result to length of shorted input list', () => {
const expectedA = [
[ 1, 'A' ],
[ 2, 'B' ],
]
const actualA = zip([ 1, 2 ], array2)
expect(actualA).toEqual(expectedA)
const expectedB = [
[ 1, 'A' ],
[ 2, 'B' ],
]
const actualB = zip(array1, [ 'A', 'B' ])
expect(actualB).toEqual(expectedB)
})
Typescript test
import {zip} from 'rambda'
describe('R.zip', () => {
it('happy', () => {
const array1 = [1, 2, 3]
const array2 = ['A', 'B', 'C']
const result = zip(array1)(array2)
result
})
})
zipObj
zipObj<T, K extends string>(keys: K[], values: T[]): { [P in K]: T }
It will return a new object with keys of keys
array and values of values
array.
All Typescript definitions
zipObj<T, K extends string>(keys: K[], values: T[]): { [P in K]: T };
zipObj<K extends string>(keys: K[]): <T>(values: T[]) => { [P in K]: T };
zipObj<T, K extends number>(keys: K[], values: T[]): { [P in K]: T };
zipObj<K extends number>(keys: K[]): <T>(values: T[]) => { [P in K]: T };
R.zipObj source
import { take } from './take.js'
export function zipObj(keys, values){
if (arguments.length === 1) return yHolder => zipObj(keys, yHolder)
return take(values.length, keys).reduce((
prev, xInstance, i
) => {
prev[ xInstance ] = values[ i ]
return prev
}, {})
}
Tests
import { equals } from './equals.js'
import { zipObj } from './zipObj.js'
test('zipObj', () => {
expect(zipObj([ 'a', 'b', 'c' ], [ 1, 2, 3 ])).toEqual({
a : 1,
b : 2,
c : 3,
})
})
test('0', () => {
expect(zipObj([ 'a', 'b' ])([ 1, 2, 3 ])).toEqual({
a : 1,
b : 2,
})
})
test('1', () => {
expect(zipObj([ 'a', 'b', 'c' ])([ 1, 2 ])).toEqual({
a : 1,
b : 2,
})
})
test('ignore extra keys', () => {
const result = zipObj([ 'a', 'b', 'c', 'd', 'e', 'f' ], [ 1, 2, 3 ])
const expected = {
a : 1,
b : 2,
c : 3,
}
expect(equals(result, expected)).toBeTrue()
})
Typescript test
import {zipObj} from 'rambda'
describe('R.zipObj', () => {
it('happy', () => {
const result = zipObj(['a', 'b', 'c', 'd'], [1, 2, 3])
result
})
it('imported from @types/ramda', () => {
const result = zipObj(['a', 'b', 'c'], [1, 2, 3])
const curriedResult = zipObj(['a', 'b', 'c'])([1, 2, 3])
result
curriedResult
})
})
zipWith
zipWith<T, U, TResult>(fn: (x: T, y: U) => TResult, list1: T[], list2: U[]): TResult[]
All Typescript definitions
zipWith<T, U, TResult>(fn: (x: T, y: U) => TResult, list1: T[], list2: U[]): TResult[];
zipWith<T, U, TResult>(fn: (x: T, y: U) => TResult, list1: T[]): (list2: U[]) => TResult[];
zipWith<T, U, TResult>(fn: (x: T, y: U) => TResult): (list1: T[], list2: U[]) => TResult[];
R.zipWith source
import { curry } from './curry.js'
import { take } from './take.js'
function zipWithFn(
fn, x, y
){
return take(x.length > y.length ? y.length : x.length, x).map((xInstance, i) => fn(xInstance, y[ i ]))
}
export const zipWith = curry(zipWithFn)
Tests
import { add } from './add.js'
import { zipWith } from './zipWith.js'
const list1 = [ 1, 2, 3 ]
const list2 = [ 10, 20, 30, 40 ]
const list3 = [ 100, 200 ]
test('when second list is shorter', () => {
const result = zipWith(
add, list1, list3
)
expect(result).toEqual([ 101, 202 ])
})
test('when second list is longer', () => {
const result = zipWith(
add, list1, list2
)
expect(result).toEqual([ 11, 22, 33 ])
})
Typescript test
import {zipWith} from 'rambda'
const list1 = [1, 2]
const list2 = [10, 20, 30]
describe('R.zipWith', () => {
it('happy', () => {
const result = zipWith(
(x, y) => {
x
y
return `${x}-${y}`
},
list1,
list2
)
result
})
it('curried', () => {
const result = zipWith((x, y) => {
x
y
return `${x}-${y}`
})(list1, list2)
result
})
})
❯ CHANGELOG
7.1.0
-
Add R.mergeRight
- introduced by Ramda's latest release. While Ramda renames R.merge
, Rambda will keep R.merge
.
-
Rambda's pipe/compose
doesn't return proper length of composed function which leads to issue with R.applySpec
. It was fixed by using Ramda's pipe/compose
logic - Issue #627
-
Replace Async
with Promise
as return type of R.type
.
-
Add new types as Typescript output for R.type
- "Map", "WeakMap", "Generator", "GeneratorFunction", "BigInt", "ArrayBuffer"
-
Add R.juxt
method
-
Add R.propSatisfies
method
-
Add new methods after Ramda
version upgrade to 0.28.0
:
-- R.count
-- R.modifyPath
-- R.on
-- R.whereAny
-- R.partialObject
7.0.3
Rambda.none has wrong logic introduced in version 7.0.0
- Issue #625
7.0.2
Rambda doesn't work with pnpm
due to wrong export configuration - Issue #619
7.0.1
- Wrong ESM export configuration in
package.json
- Issue #614
7.0.0
- Braking change - sync
R.compose
/R.pipe
with @types/ramda
. That is significant change so as safeguard, it will lead a major bump. Important - this lead to raising required Typescript version to 4.2.2
. In other words, to use Rambda
you'll need Typescript version 4.2.2
or newer.
Related commit in @types/ramda
- https://github.com/DefinitelyTyped/DefinitelyTyped/commit/286eff4f76d41eb8f091e7437eabd8a60d97fc1f#diff-4f74803fa83a81e47cb17a7d8a4e46a7e451f4d9e5ce2f1bd7a70a72d91f4bc1
There are several other changes in @types/ramda
as stated in this comment. This leads to change of typings for the following methods in Rambda:
-- R.unless
-- R.toString
-- R.ifElse
-- R.always
-- R.complement
-- R.cond
-- R.is
-- R.sortBy
-- R.dissoc
-- R.toPairs
-- R.assoc
-- R.toLower
-- R.toUpper
-
One more reason for the braking change is changing of export declarations in package.json
based on this blog post and this merged Ramda's PR. This also led to renaming of babel.config.js
to babel.config.cjs
.
-
Add R.apply
, R.bind
and R.unapply
-
R.startsWith/R.endsWith
now support lists as inputs. This way, it matches current Ramda behavior.
-
Remove unused typing for R.chain
.
-
R.map
/R.filter
no longer accept bad inputs as iterable. This way, Rambda behaves more like Ramda, which also throws.
-
Make R.lastIndexOf
follow the logic of R.indexOf
.
-
Change R.type
logic to Ramda logic. This way, R.type
can return Error
and Set
as results.
-
Add missing logic in R.equals
to compare sets - Issue #599
-
Improve list cloning - Issue #595
-
Handle multiple inputs with R.allPass
and R.anyPass
- Issue #604
-
Fix R.length
wrong logic with inputs as {length: 123}
- Issue #606.
-
Improve non-curry typings of R.merge
by using types from mobily/ts-belt.
-
Improve performance of R.uniqWith
.
-
Wrong R.update
if index is -1
- PR #593
-
Make R.eqProps
safe for falsy inputs - based on this opened Ramda PR.
-
Incorrect benchmarks for R.pipe/R.compose
- Issue #608
-
Fix R.last/R.head
typings - Issue #609
6.9.0
Fixing R.uniq
was done by improving R.indexOf
which has performance implication to all methods importing R.indexOf
:
-
R.includes
-
R.intersection
-
R.difference
-
R.excludes
-
R.symmetricDifference
-
R.union
-
R.without no longer support the following case - without('0:1', ['0', '0:1']) // => ['0']
. Now it throws as the first argument should be a list, not a string. Ramda, on the other hand, returns an empty list - https://github.com/ramda/ramda/issues/3086.
6.8.3
-
Fix Typescript build process with rambda/immutable
- Issue #572
-
Add R.objOf
method
-
Add R.mapObjIndexed
method
-
Publish shorter README.md version to NPM
6.8.0
-
R.has
use Object.prototype.hasOwnProperty
- Issue #572
-
Expose immutable.ts
typings which are Rambda typings with readonly
statements - Issue #565
-
Fix R.intersection
wrong order compared to Ramda.
-
R.path
wrong return of null
instead of undefined
when path value is null
- PR #577
6.7.0
- Remove
ts-toolbelt
types from Typescript definitions. Most affected are the following methods, which lose one of its curried definitions:
- R.maxBy
- R.minBy
- R.pathEq
- R.viewOr
- R.when
- R.merge
- R.mergeDeepRight
- R.mergeLeft
6.6.0
-
Change R.piped
typings to mimic that of R.pipe
. Main difference is that R.pipe
is focused on unary functions.
-
Fix wrong logic when R.without
use R.includes
while it should use array version of R.includes
.
-
Use uglify plugin for UMD bundle.
-
Remove dist
folder from .gitignore
in order to fix Deno
broken package. Issue #570
-
Improve R.fromPairs
typings - Issue #567
6.5.3
- Wrong logic where
R.without
use R.includes
while it should use the array version of R.includes
This is Ramda bug, that Rambda also has before this release - https://github.com/ramda/ramda/issues/3086
6.5.2
6.5.1
Fix wrong versions in changelog
6.5.0
-
R.defaultTo
no longer accepts infinite inputs, thus it follows Ramda implementation.
-
R.equals
supports equality of functions.
-
R.pipe
doesn't use R.compose
.
-
Close Issue #561 - export several internal TS interfaces and types
-
Close Issue #559 - improve R.propOr
typings
-
Add CHANGELOG.md
file in release files list
6.4.0
-
Close Issue #560 - apply immutable lint to Typescript definitions
-
Close Issue #553 - fix problem with curried typings of R.prop
-
Fix wrong R.last
typing
-
Upgrade all rollup
related dependencies
-
R.type
supports Symbol
just like Ramda.
-
Remove file extension in main
property in package.json
in order to allow experimental-modules
. See also this Ramda's PR - https://github.com/ramda/ramda/pull/2678/files
-
Import R.indexBy
/R.when
/R.zipObj
/R.propEq
/R.complement
changes from recent @types/ramda
release.
-
R.tryCatch
stop supporting asynchronous functions; the previous behaviour is exported to Rambdax as R.tryCatchAsync
6.3.1
- Fix missing
Evolved
declaration in Typescript definition
6.3.0
6.2.0
-
Add R.props
-
Add R.zipWith
-
Add R.splitAt
-
Add R.splitWhen
-
Close Issue #547 - restore readonly
declaration in Typescript definitions.
-
R.append
/R.prepend
now work only with arrays just like Ramda. Previous behaviour was for them to work with both arrays and strings.
-
Sync R.pluck
typings with @types/ramda
as there was a tiny difference.
6.1.0
6.0.1
- Fix typing of
R.reject
as it wrongly declares that with object, it pass property to predicate.
6.0.0
-
Breaking change - R.map
/R.filter
/R.reject
/R.forEach
/R.partition
doesn't pass index as second argument to the predicate, when looping over arrays. The old behaviour of map, filter and forEach can be found in Rambdax methods R.mapIndexed, R.filterIndexed and R.forEachIndexed.
-
Breaking change - R.all
/R.none
/R.any
/R.find
/R.findLast
/R.findIndex
/R.findLastIndex
doesn't pass index as second argument to the predicate.
-
Change R.assocPath
typings so the user can explicitly sets type of the new object
-
Typings of R.assoc
match its @types/ramda
counterpart.
-
Simplify R.forEach
typings
-
Remove ReadonlyArray<T>
pattern from Typescript definitions - not enough value for the noise it adds.
5.13.1
5.13.0
5.12.1
-
Close Issue #524 -
wrong R.assocPath
when path includes numbers
-
R.includes
throws on wrong input, i.e. R.includes(1, null)
5.12.0
-
Add R.move
method
-
Add R.union
method
-
Close Issue #519 -
ts-toolbelt
needs other type of export with --isolatedModules
flag
-
Change R.when
implementation and typings to match those of Ramda
-
R.over
and R.set
use R.curry
instead of manual currying
-
R.lensPath
typings support string as path, i.e. 'a.b'
instead of ['a', 'b']
-
R.equals
now supports negative zero just like Ramda.equals
-
R.replace
uses R.curry
5.11.0
Forgot to export R.of
because of wrong marker in files/index.d.ts
5.10.0
Close Issue #514 -
wrong R.length
with empty string
Close Issue #511 - error in ts-toolbelt
library
Close Issue #510 - R.clamp
should throw if min argument is greater than max argument
-
PR #508 - add R.of
-
Definition of R.curry
are not same as those of @types/ramda
-
Definitions of R.either
is same as that of R.both
-
Definitions of R.ifElse
no longer use any
type
-
Definition of R.flatten
requires passing type for the output
-
Fix definition of R.propOr
, R.dissoc
-
Fix curried definitions of R.take
, R.takeLast
, R.drop
and R.dropLast
-
5.9.0
-
R.pickAll
definition allows passing string as path to search.
-
R.propEq
definition is now similar to that in @types/ramda
.
-
R.none
matches R.all
implementation and pass index as second argument to predicate input.
-
R.reduce
- drop support for object as iterable. Now it throws the same error as Ramda. Also instead of returning the initial value when iterable is undefined
, now it throws.
Add index as additional argument to the Typescript definitions of the following methods:
-
R.all
-
R.find
-
R.findLast
-
R.findIndex
-
R.findLastIndex
-
5.8.0
Add R.mergeAll
Add R.mergeDeepRight
Add R.mergeLeft
Add R.partition
Add R.pathEq
Add R.tryCatch
Add R.unless
Add R.whereEq
Add R.where
-
Add R.last
typing for empty array
-
5.7.0 Revert PR #469 as R.curry
was slow | Also now R.flip
throws if arity is greater than or equal to 5
-
5.6.3 Merge several PRs of @farwayer
-
PR #482 - improve R.forEach
performance by not using R.map
-
PR #485 - improve R.map
performance
-
PR #482 - improve R.reduce
performance
-
Fix missing high arity typings for R.compose/pipe
-
R.merge
definitions match those of @types/ramda
-
Remove dist
folder from Rambda repo
-
5.6.2
Close Issue #476 - typesafe R.propEq
definitions
Approve PR #477 - fix R.groupWith
when list length is 1
Update ts-toolbelt
files as now there is update pipeline for it.
Approve PR #474 - intruduce internal isArray
helper
Approve PR #469 - R.flip supports any arity | implement R.curry
with R.curryN
add R.applySpec
Close Issue #464 - R.flip
should handle functions with arity above 2
Close Issue #468 - fs-extra
should be dev dependency as it was wrongly added as production dependency in 5.2.0
R.flip
typings now match @types/ramda
typings
Add R.hasPath
method
Add R.mathMod
typings
Fix R.omit
typings
Fix R.pick
typings
Close Issue #460 - R.paths
should be curried
Close Issue #458 - wrong R.propIs
typing
Close Issue #408 - add R.chain
Close Issue #430 - add R.when
Also restore R.converge
, R.findLast
, R.findLastIndex
and R.curryN
as I have forgotten to export them when releasing 5.2.0
.
Fix Typescript comment for every method
Release new documentation site
Ramda
repo now holds all Rambdax
methods and tests
Add R.converge
and R.curryN
from PR #412
Close Issue #410 - wrong implementation of R.groupWith
Close Issue #411 - change the order of declared R.map
typings rules
Move R.partialCurry
to Rambdax(reason for major bump).
Use new type of export in Typescript definitions.
Approve PR #381 - add R.applySpec
Approve PR #375 - add lenses(Thank you @synthet1c)
Add R.lens
Add R.lensIndex
Add R.lensPath
Add R.lensProp
Add R.over
Add R.set
Add R.view
Sync with Ramda 0.27
Add R.paths
Add R.xor
Close Issue #373
Add R.cond
Close Issue #317 - add R.transpose
Close Issue #325 - R.filter
should return equal values for bad inputs null
and undefined
Approve suggestion for R.indexBy
to accept string not only function as first argument.
Edit of R.path
typings
-
4.2.0 Approve PR #314 - add R.and
-
4.1.1 Add missing typings for R.slice
-
4.1.0 Add R.findLast
and R.findLastIndex
-
4.0.2 Fix R.isEmpty
wrong behaviour compared to the Ramda method
-
4.0.1 Approve PR #289 - remove console.log in R.values
method
-
4.0.0 Multiple breaking changes as Rambda methods are changed in order to increase the similarity between with Ramda
Add to Differences
:
R.type can return 'NaN'
R.compose doesn't pass `this` context
R.clone doesn't work with number, booleans and strings as input
All breaking changes:
-- R.add works only with numbers
-- Fix R.adjust which had wrong order of arguments
-- R.adjust works when index is out of bounds
-- R.complement support function with multiple arguments
-- R.compose/pipe throws when called with no argument
-- R.clone works with Date
value as input
-- R.drop/dropLast/take/takeLast always return new copy of the list/string
-- R.take/takeLast return original list/string with negative index
-- R.equals handles NaN
and RegExp
types
-- R.type/R.equals supports new Boolean/new Number/new Date/new String
expressions
-- R.has works with non-object
-- R.ifElse pass all arguments
-- R.length works with bad input
-- R.propEq work with bad input for object argument
-- R.range work with bad inputs
-- R.times work with bad inputs
-- R.reverse works with strings
-- R.splitEvery throws on non-positive integer index
-- R.test throws just like Ramda when first argument is not regex
-- R.values works with bad inputs
-- R.zipObj ignores extra keys
This is pre 4.0.0
release and it contains all of the above changes
Close issue #287 - ts-toolbelt
directory was changed but not reflected in files
property in package.json
Close issue #273 - ts-toolbelt needs other type of export when isolatedModules
TypeScript property
Close issue #245 - complete typings tests for methods that have more specific Typescript definitions
Close issue #263 - broken curry typing solved by ts-toolbelt
local dependency.
Add R.partialCurry
typings.
Approve PR #266 that adds R.slice
method.
-
3.1.0 This might be breaking change for Typescript users, as very different definitions are introduced. With the previous state of the definitions, it was not possible to pass dtslint
typings tests.
-
R.either
and R.both
supports multiple arguments as they should.
-
Several methods added by @squidfunk - R.assocPath
, R.symmetricDifference
, R.intersperse
, R.intersection
and R.difference
-
3.0.1 Close issue #234 - wrong curry typing
-
3.0.0 Deprecate R.contains
, while R.includes
is now following Ramda API(it uses R.equals
for comparision)
-
2.14.5 R.without
needs currying
-
2.14.4 Close issue #227 - add index as third argument of R.reduce
typings
-
2.14.2 Use R.curry
with R.reduce
as manual curry there didn't work as expected.
-
2.14.1 Fix wrong typescript with R.head
- PR #228 pushed by @tonivj5
-
2.14.0 Add R.groupWith
by @selfrefactor | Add R.propOr
, R.mathMod
, R.mean
, R.median
, R.negate
, R.product
by @ku8ar
-
2.13.0 Add R.identical
- PR #217 pushed by @ku8ar
-
2.12.0 Add R.propIs
- PR #213 and add R.sum
- issue #207
-
2.11.2 Close Rambdax issue #32 - wrong R.type
when function is input
-
2.11.1 Approve PR #182 - Changed typings to allow object as input to R.forEach
and R.map
-
2.11.0 Approve PR #179 - R.adjust
handles negative index; R.all
doesn't need R.filter
-
2.10.2 Close issue #175 - missing typescript file
-
2.10.0 Approve huge and important PR #171 submitted by @helmuthdu - Add comments to each method, improve Typescript support
-
2.9.0 R.toPairs
and R.fromPairs
-
2.8.0 Approve PR #165 R.clone
-
2.7.1 expose src
| Discussed at issue #147
-
2.7.0 Approve PR #161 R.isEmpty
-
2.6.0 R.map
, R.filter
and R.forEach
pass original object to iterator as third argument | Discussed at issue #147
-
2.5.0 Close issue #149 Add R.partial
| R.type
handles NaN
-
2.4.0 Major bump of Rollup
; Stop building for ES5
-
2.3.1 Close issue #90 | Add string type of path in R.pathOr
-
2.3.0 Close issue #89 | Fix missing Number
TS definition in R.type
-
2.2.0 R.defaultTo
accepts indefinite number of input arguments. So the following is valid expression: const x = defaultTo('foo',null, null, 'bar')
-
2.1.0 Restore R.zip
using WatermelonDB implementation.
-
2.0.0 Major version caused by removing of R.zip
and R.addIndex
. Issue #85 rightfully finds that the implementation of R.addIndex
is not correct. This led to removing this method and also of R.zip
as it had depended on it. The second change is that R.map
, R.filter
are passing array index as second argument when looping over arrays. The third change is that R.includes
will return false
if input is neigher string
nor array
. The previous behaviour was to throw an error. The last change is to increase the number of methods that are passing index as second argument to the predicate function.
-
1.2.6 Use src
folder instead of modules
-
1.2.5 Fix omit
typing
-
1.2.4 Add missing Typescript definitions - PR#82
-
1.2.2 Change curry method used across most of library methods
-
1.2.1 Add R.assoc
| fix passing undefined
to R.map
and R.merge
issue #77
-
1.2.0 Add R.min
, R.minBy
, R.max
, R.maxBy
, R.nth
and R.keys
-
1.1.5 Close issue #74 R.zipObj
-
1.1.4 Close issue #71 CRA fail to build rambda
-
1.1.3 Approve PR #70 implement R.groupBy
| Close issue #69
-
1.1.2 Approve PR #67 use babel-plugin-annotate-pure-calls
-
1.1.1 Approve PR #66 R.zip
-
1.1.0 R.compose
accepts more than one input argument issue #65
-
1.0.13 Approve PR #64 R.indexOf
-
1.0.12 Close issue #61 make all functions modules
-
1.0.11 Close issue #60 problem with babelrc
-
1.0.10 Close issue #59 add R.dissoc
-
1.0.9 Close issue #58 - Incorrect R.equals
-
1.0.8 R.map
and R.filter
pass object properties when mapping over objects
-
1.0.7 Add R.uniqWith
-
1.0.6 Close issue #52 - ES5 compatible code
-
1.0.5 Close issue #51
-
1.0.4 Close issue #50 - add R.pipe
typings
-
1.0.3 R.ifElse
accept also boolean as condition argument
-
1.0.2 Remove typedDefaultTo
and typedPathOr
| Add R.pickAll
and R.none
-
1.0.0 Major change as build is now ES6 not ES5 compatible (Related to issue #46)| Making Rambda
fully tree-shakeable| Edit Typescript definition
-
0.9.8 Revert to ES5 compatible build - issue #46
-
0.9.7 Refactor for Rollup
tree-shake | Remove R.padEnd
and R.padStart
-
0.9.6 Close issue #44 - R.reverse
mutates the array
-
0.9.5 Close issue #45 - invalid Typescript typings
-
0.9.4 Add R.reject
and R.without
(PR#41 PR#42) | Remove 'browser' field in package.json
due to Webpack bug 4674
-
0.9.3 Add R.forEach
and R.times
-
0.9.2 Add Typescript
definitions
-
0.9.1 Close issue #36 - move current behaviour of defaultTo
to a new method typedDefaultTo
; make defaultTo
follow Ramda spec; add pathOr
; add typedPathOr
.
-
0.9.0 Add R.pipe
PR#35
-
0.8.9 Add R.isNil
-
0.8.8 Migrate to ES modules PR33 | Add R.flip to the API | R.map/filter works with objects
-
0.8.7 Change Webpack
with Rollup
- PR29
-
0.8.6 Add R.tap
and R.identity
-
0.8.5 Add R.all
, R.allPass
, R.both
, R.either
and R.complement
-
0.8.4 Learning to run yarn test
before yarn publish
the hard way
-
0.8.3 Add R.always
, R.T
and R.F
-
0.8.2 Add concat
, padStart
, padEnd
, lastIndexOf
, toString
, reverse
, endsWith
and startsWith
methods
-
0.8.1 Add R.ifElse
-
0.8.0 Add R.not
, R.includes
| Take string as condition for R.pick
and R.omit
-
0.7.6 Fix incorrect implementation of R.values
-
0.7.5 Fix incorrect implementation of R.omit
-
0.7.4 issue #13 - Fix R.curry
, which used to return incorrectly function
when called with more arguments
-
0.7.3 Close issue #9 - Compile to es2015
; Approve PR #10 - add R.addIndex
to the API
-
0.7.2 Add Promise
support for R.type
-
0.7.1 Close issue #7 - add R.reduce
to the API
-
0.7.0 Close issue #5 - change name of curry
to partialCurry
; add new method curry
, which works just like Ramda's curry
-
0.6.2 Add separate documentation site via docsify
❯ Additional info
Most influential contributors
-
@farwayer - improving performance in R.find, R.filter; give the idea how to make benchmarks more reliable;
-
@thejohnfreeman - add R.assoc, R.chain;
-
@helmuthdu - add R.clone; help improve code style;
-
@jpgorman - add R.zip, R.reject, R.without, R.addIndex;
-
@ku8ar - add R.slice, R.propOr, R.identical, R.propIs and several math related methods; introduce the idea to display missing Ramda methods;
-
@romgrk - add R.groupBy, R.indexBy, R.findLast, R.findLastIndex;
-
@squidfunk - add R.assocPath, R.symmetricDifference, R.difference, R.intersperse;
-
@synthet1c - add all lenses methods; add R.applySpec, R.converge;
-
@vlad-zhukov - help with configuring Rollup, Babel; change export file to use ES module exports;
Rambda references
Links to Rambda
Deprecated from Used by
section
Releases
Rambda's releases before 6.4.0 were used mostly for testing purposes.
My other libraries