zeelib / Exports
Utility library in TypeScript, with a focus on Node and FP utils and emphasis on not rewriting builtin features.
npm i zeelib
See the docs below for details (generated from types and comments). Example:
import * as z from 'zeelib'
const answer = await z.prompt('Pick a letter')
if (z.isEmpty(answer)) process.exit(1)
Ƭ AnyFn: (...args: any[]) => any
▸ (...args): any
| Name | Type |
|---|---|
...args | any[] |
any
Ƭ AnyMap: Record<string, any>
Ƭ Cb: (error: c.ExecFileException | null, stdout: string | Buffer, stderr: string | Buffer) => void
▸ (error, stdout, stderr): void
| Name | Type |
|---|---|
error | c.ExecFileException | null |
stdout | string | Buffer |
stderr | string | Buffer |
void
Ƭ ColMap: Record<string, (t: string) => string>
Ƭ F: (...args: any[]) => any
▸ (...args): any
| Name | Type |
|---|---|
...args | any[] |
any
Ƭ Listener: (a: AnyMap, b: AnyMap) => any
▸ (a, b): any
| Name | Type |
|---|---|
a | AnyMap |
b | AnyMap |
any
Ƭ R: (...args: any[]) => Timer
▸ (...args): Timer
| Name | Type |
|---|---|
...args | any[] |
Ƭ R: string | any[] | AnyMap
Ƭ Timer: NodeJS.Timeout | number | null
Ƭ Updater: (a: AnyMap) => AnyMap
▸ (a): AnyMap
| Name | Type |
|---|---|
a | AnyMap |
• Const colorize: ColMap
▸ and<T>(a): boolean
Returns false if any in input array is false
| Name |
|---|
T |
| Name | Type |
|---|---|
a | T[] |
boolean
Example
and([ 1, 2, 3 ]) // => true
and([ 1, 2, 3, false ]) // => false
▸ average(xs): number
Averages a list of numbers
| Name | Type |
|---|---|
xs | number[] |
number
Example
average([ 2, 4, 6, 8 ]) // => 5
▸ capitalizeFirstChar(str): string
Capitalizes the first character of string
| Name | Type |
|---|---|
str | string |
string
Example
capitalizeFirstChar('things and stuff') // => 'Things and stuff'
▸ chunk<T>(arr, n): T[][]
Splits an array into chunks
| Name |
|---|
T |
| Name | Type |
|---|---|
arr | T[] |
n | number |
T[][]
Example
chunk([1, 2, 3, 4 ], 2) // => [ [ 1, 2 ], [ 3, 4 ] ]
▸ clamp(val, min, max): number
Takes a number, min, and max If number is between min and max, returns number Otherwise returns min or max
| Name | Type |
|---|---|
val | number |
min | number |
max | number |
number
Example
clamp(100, 0, 1000) // => 100
clamp(100, 101, 1000) // => 101
clamp(100, 0, 99) // => 00
▸ collapseNewlines(str): string
Collapses multiple newlines to two
| Name | Type |
|---|---|
str | string |
string
Example
collapseNewlines('\n\n\n\n') // => '\n\n'
▸ collapseWhitespace(str): string
Collapses consecutive whitespace to a single space
| Name | Type |
|---|---|
str | string |
string
Example
collapseWhitespace('a\n\r\t\nb') // => 'a b'
▸ collectBy(p): (a: any[]) => AnyMap
Collect an an array of objects by string key cred: gh:uniqname
| Name | Type |
|---|---|
p | string |
fn
▸ (a): AnyMap
| Name | Type |
|---|---|
a | any[] |
Example
const data = [ { foo: 'a', bar: 'baz' }, { foo: 'b', bar: 'quux' }, { foo: 'a', bar: 'whatever' } ]
collectBy('foo')(data) // => { a: { foo: 'a', bar: 'whatever' }, b: { foo: 'b', bar: 'quux' } }
▸ combineRegex(rs, opts?): RegExp
Combines regular expressions
| Name | Type | Default value |
|---|---|---|
rs | RegExp[] | undefined |
opts | string | '' |
RegExp
Example
combineRegex([/[a-z]/, /[0-9]], 'g') ==> /[a-z][0-9]/g
▸ compose<T>(...fns): (t: T) => T
Right to left composition
| Name |
|---|
T |
| Name | Type |
|---|---|
...fns | (t: T) => T[] |
fn
▸ (t): T
| Name | Type |
|---|---|
t | T |
T
Example
const addOne = (a) => a + 1
const timesTwo = (a) => a * 2
compose(addOne, timesTwo)(2) // => 5
▸ countIn<T>(el, ls): number
Find out how many of a given element is in an array or string.
| Name |
|---|
T |
| Name | Type |
|---|---|
el | T |
ls | string | T[] |
number
Example
countIn('a', 'abc') // => 1
countIn('a', [ 'a', 'b', 'c' ]) // => 1
▸ curry<T>(fn): F
Takes a function and returns a function that takes any number of arguments
Produces a curried function
| Name |
|---|
T |
| Name | Type |
|---|---|
fn | F |
Example
const addThree = (a, b, c) => a + b + c
curry(addThree)(1)(1)(1) // => 3
▸ debounce(fn, ms): R
Simple debounce
| Name | Type |
|---|---|
fn | (...args: any) => any |
ms | number |
Example
debounce(() => console.log('hi'), 5000)
▸ diff<T>(a, b): T[]
Diff two arrays
| Name |
|---|
T |
| Name | Type |
|---|---|
a | T[] |
b | T[] |
T[]
Example
diff([ 1, 2, 3 ], [ 2, 3 ]) // => [ 1 ]
▸ div(ns): number
Divide any amount of numbers
| Name | Type |
|---|---|
ns | number[] |
number
Example
div([ 4, 2, 1 ]) // => 2
▸ drop<A>(n, arr): A[]
Like Haskell's drop
| Name |
|---|
A |
| Name | Type |
|---|---|
n | number |
arr | A[] |
A[]
Example
drop(2, [ 1, 2, 3 ]) // => 3
▸ dropWhile<T>(pred, arr): T[]
The opposite of takeWhile:
takes a predicate and array and returns an
array of the elements that didn't pass the predicate
| Name |
|---|
T |
| Name | Type |
|---|---|
pred | (x: T) => boolean |
arr | T[] |
T[]
Example
dropWhile(lessThanThree, [ 1, 2, 3, 4 ]) // => [ 3, 4 ]
▸ each<T>(xs, fn): Record<string, any> | T[]
Takes an array or object and a function, and runs the function on each element
| Name |
|---|
T |
| Name | Type |
|---|---|
xs | string | any[] | Record<string, any> |
fn | (a: any, b: string | number) => T |
Record<string, any> | T[]
Example
each([ 'a', 'b', 'c' ], id) // => 'a'
▸ escapeForRegex(s?): string
| Name | Type | Default value |
|---|---|---|
s | string | '' |
string
Example
escapeForRegex('foo') // => foo
escapeForRegex('1 \\ {} []|') // => '1 \\\\ \{\} \\[\\]\\|'
▸ execute(cmd): void
Like a standalone npm run that obeys npm bin
| Name | Type |
|---|---|
cmd | string |
void
Example
execute('standard-format -w')
▸ fileExists(filePath): Promise<boolean>
Returns bool based on if passed path exists
| Name | Type |
|---|---|
filePath | string |
Promise<boolean>
Example
await fileExists('./foo') // => Promise<true>
▸ filter<T>(fn, list): T[] | Record<string, T>
filter for array and object
| Name |
|---|
T |
| Name | Type |
|---|---|
fn | (x: T, y: string | number) => boolean |
list | string | AnyMap | T[] |
T[] | Record<string, T>
Example
filter(id, [ 1, 2 ]) // => [ 1, 2 ]
filter(lessThanThree, [ 1, 2, 3, 4 ]) // => [ 1, 2 ]
filter(lessThanThree, { a: 1, b: 4 }) // => { a: 1 }
▸ findIndices(el, arr): number[]
Find all indices of an item in an array
| Name | Type |
|---|---|
el | any |
arr | any[] |
number[]
Example
findIndices(1, [ 1, 2, 1 ]) // => [ 0, 2 ]
▸ findPort(port, cb): void
Find next open port
| Name | Type |
|---|---|
port | number |
cb | (x: null | Error, y?: number) => void |
void
Example
findPort(8000, (err, port) => console.log(`${port} is open`))
▸ flattenAndUniq<T>(arr): T[]
Recursively flatten arrays then uniq what's left
| Name |
|---|
T |
| Name | Type |
|---|---|
arr | T[] |
T[]
Example
flattenAndUniq([ 1, 2, 3, [ 1, 2, 3 ]]) // => [ 1, 2, 3 ]
▸ flip(f): (...args: any[]) => any
Flips order of received arguments and calls f.
| Name | Type |
|---|---|
f | (...xs: any[]) => any |
fn
▸ (...args): any
| Name | Type |
|---|---|
...args | any[] |
any
Example
const minus = (a, b) => a - b
minus(2, 1) // => 1
flip(minus)(2, 1) // => -1
▸ fold<T>(f, a): T
Applies f to first two items of list, then to next, etc.
| Name |
|---|
T |
| Name | Type |
|---|---|
f | (x: T, y: T) => T |
a | T[] |
T
Example
foldl1(increment, [ 1, 1, 1 ]) // => 3
▸ getFreeDisk(): number
Get free disk space
number
Example
getFreeDisk()
▸ getFreeMemory(): number
Get free memory
number
Example
getFreeMemory()
▸ getGlobal(): undefined | typeof globalThis
Gets the global for your current context.
undefined | typeof globalThis
Example
getGlobal() // => window, global, whatever
▸ getHashFromDate(): string
Returns a hash based on current timestamp
string
Example
getHashFromDate()
▸ getHashFromSystem(): string
Get a md5 hash based on hostname, process.ppid, and date
string
Example
getHashFromSystem()
▸ getKeyByValue(value, object): undefined | string
Get the key for a value
| Name | Type |
|---|---|
value | any |
object | AnyMap |
undefined | string
Example
getKeyByValue('bar', { foo: 'bar' }) // => 'foo'
▸ getLoadAverage(): number
Get load average
number
Example
getLoadAverage()
▸ getMemoryUsage(): number
Get memory usage
number
Example
getMemoryUsage()
▸ getOrdinal(n): string
Adds ordinal onto integer
Works up to 999
| Name | Type |
|---|---|
n | number |
string
Example
getOrdinal(1) // => '1st'
▸ getProjectRoot(): string
Get project root
string
Example
getProjectRoot() // /path/to/project
▸ getRegexFlags(r): string[]
Returns the flags for a given regular expression
| Name | Type |
|---|---|
r | RegExp |
string[]
Example
getRegexFlags(/foo/ig) // => [ 'g', 'i' ]
▸ getStdin(f): void
Get stdin and do something with it.
| Name | Type |
|---|---|
f | (a: string) => void |
void
Example
getStdin((str) => {
console.log(str.split(''))
})
▸ getTerminalColumns(): number
Get columns of current terminal
number
Example
getTerminalColumns()
▸ getTerminalRows(): number
Get current terminal rows
number
Example
getTerminalRows()
▸ getTerminalSize(): Size
Returns size of the current terminal
Example
getTerminalSize() // => { columns: number, rows: number }
▸ getUserHome(): string
Get current user's home directory
string
Example
getUserHome() // => /home/z
▸ getUserShell(): string
Get the current user's shell, or an empty string on shell-less platforms
string
Example
getUserShell()
▸ greater(a, b): number
Get the greater of two numbers
| Name | Type |
|---|---|
a | number |
b | number |
number
Example
greater(1, 2) // => 2
▸ groupBy(p): (a: any[]) => AnyMap
Collect an an array of objects by string key
| Name | Type |
|---|---|
p | string |
fn
▸ (a): AnyMap
| Name | Type |
|---|---|
a | any[] |
Example
const data = [ { foo: 'a', bar: 'baz' }, { foo: 'b', bar: 'quux' }, { foo: 'a', bar: 'whatever' } ]
groupBy('foo')(data) // => { a: { foo: 'a', bar: 'whatever' }, b: { foo: 'b', bar: 'quux' } }
▸ has(p, o): boolean
See if an object has a property
| Name | Type |
|---|---|
p | string |
o | AnyMap |
boolean
Example
has('a' { b: 'c' }) // => false
▸ hasColor(): boolean
Returns true if the current terminal supports color
boolean
Example
hasColor()
▸ hasDuplicate<T>(arr): boolean
Returns true if an array has any duplicate elements
| Name |
|---|
T |
| Name | Type |
|---|---|
arr | T[] |
boolean
Example
hasDuplicate([ 1, 1, 2 ]) // => true
▸ head<T>(arr): T
First element
| Name |
|---|
T |
| Name | Type |
|---|---|
arr | T[] |
T
Example
head([ 1, 2, 3 ]) // => 1
▸ id<A>(a): A
id
| Name |
|---|
A |
| Name | Type |
|---|---|
a | A |
A
Example
id(1) // => 1
id() // => undefined
▸ init(arr): any[]
Returns all but the last item of an array
| Name | Type |
|---|---|
arr | any[] |
any[]
Example
init([ 1, 2, 3 ]) // => [ 1, 2 ]
▸ initials(str): string
Trims a string to just caps
| Name | Type |
|---|---|
str | string |
string
Example
initials('Zac Anger') // => 'ZA'
▸ intersection<T>(xs, ys): T[]
Get the intersection of two arrays
| Name |
|---|
T |
| Name | Type |
|---|---|
xs | T[] |
ys | T[] |
T[]
Example
intersection([ 1, 2 ], []) // => []
intersection([ 1, 2, 3 ], [1, 2]) // => [ 1, 2 ]
▸ is(t, val): boolean
Returns true if the value is of the type
| Name | Type |
|---|---|
t | string |
val | any |
boolean
Example
is('number', 2) // => true
▸ isArrayLike(v): boolean
Returns true if the passed value is array-like
| Name | Type |
|---|---|
v | any |
boolean
Example
isArrayLike({}) // => false
isArrayLike([ 1, 2 ]) // => true
▸ isBetween(a, b, mid): boolean
Returns true if the last parameter is before the first and second parameters
| Name | Type |
|---|---|
a | number |
b | number |
mid | number |
boolean
Example
isBetween(1, 3, 2) // => true
isBetween(2, 1, 2) // => false
▸ isBoolean(v): boolean
Returns true if the value is a boolean
| Name | Type |
|---|---|
v | any |
boolean
Example
isBoolean(true) // => true
▸ isClass(fn): boolean
Returns true if passed fn is an ES2015 class
| Name | Type |
|---|---|
fn | () => any |
boolean
Example
isClass(noop) // => false
▸ isDate(v): boolean
Returns true if the value is a date
| Name | Type |
|---|---|
v | any |
boolean
Example
isDate(new Date()) // => true
▸ isDefined(v): boolean
Returns true if the value is defined
| Name | Type |
|---|---|
v | any |
boolean
Example
isDefined(null) // => true
▸ isDirectory(filePath): Promise<boolean>
Returns true if the path is a directory
| Name | Type |
|---|---|
filePath | string |
Promise<boolean>
Example
await isDirectory('.') // => true
await isDirectory('./fake-path') // => false
▸ isEmpty(v): boolean
Returns true if the value is empty
| Name | Type |
|---|---|
v | any |
boolean
Example
isEmpty('') // => true
isEmpty({}) // => true
isEmpty([]) // => true
isEmpty(null) // => true
▸ isError(a): boolean
Returns true if value is an error
| Name | Type |
|---|---|
a | any |
boolean
Example
isError(new Error()) // => true
▸ isEven(n): boolean
Returns true if the number is even
| Name | Type |
|---|---|
n | number |
boolean
Example
isEven(2) // => true
▸ isFile(filePath): Promise<boolean>
Returns true if the path is a file
| Name | Type |
|---|---|
filePath | string |
Promise<boolean>
Example
isFile('./README.md') // => true
isFile('.') // => false
▸ isFloat(n): boolean
Returns true if the number is a float
| Name | Type |
|---|---|
n | number |
boolean
Example
isFloat(2) // => false
isFloat(2.2) // => true
▸ isFunction(v): boolean
Returns true if the value is a function
| Name | Type |
|---|---|
v | any |
boolean
Example
const noop = () => {}
isFunction(2) // => false
isFunction(noop) // => true
▸ isGenerator(v): boolean
Returns true if passed val is a generator
| Name | Type |
|---|---|
v | any |
boolean
Example
isGenerator(2) // => false
▸ isGeneratorFunction(v): boolean
Returns true if val is a generator function
| Name | Type |
|---|---|
v | any |
boolean
Example
isGeneratorFunction(2) // => false
▸ isInstalled(pkgName): boolean
Returns true if the passed node_module name is installed
| Name | Type |
|---|---|
pkgName | string |
boolean
Example
isInstalled('zeelib') // => true
▸ isInteger(v): boolean
Returns true if the value is an integer
| Name | Type |
|---|---|
v | any |
boolean
Example
isInteger(2) // => true
isInteger(1.1) // => false
▸ isJson(str): boolean
Returns true if the string is valid JSON
| Name | Type |
|---|---|
str | string |
boolean
Example
isJson(JSON.stringify({ a: 'b' })) // => true
▸ isMap(v): boolean
Returns true if value is a map
| Name | Type |
|---|---|
v | any |
boolean
Example
isMap(new Map()) // => true
▸ isNode(): boolean
Returns true if code is in Node
boolean
Example
isNode()
▸ isNull(v): boolean
Returns true if the value is null
| Name | Type |
|---|---|
v | any |
boolean
Example
isNull(null) // => true
▸ isNullOrUndefined(v): boolean
Returns true if the value is null or undefined
| Name | Type |
|---|---|
v | any |
boolean
Example
isNullOrUndefined(null) // => true
▸ isNumber(v): boolean
Returns true if the value is a number and is not NaN
| Name | Type |
|---|---|
v | any |
boolean
Example
isNumber(2) // => true
isNumber(NaN) // => false
▸ isObject(v): boolean
Returns true if the value is an object
| Name | Type |
|---|---|
v | any |
boolean
Example
isObject('asdf') // => false
▸ isOdd(n): boolean
Returns true if the number is odd
| Name | Type |
|---|---|
n | number |
boolean
Example
isOdd(1) // => true
▸ isPrimitive(v): boolean
Returns true if value is a primitive
| Name | Type |
|---|---|
v | any |
boolean
Example
isPrimitive(1) // => true
▸ isPromise(a): boolean
Returns true if value is a promise
| Name | Type |
|---|---|
a | any |
boolean
Example
isPromise(Promise.resolve())
▸ isRegExp(v): boolean
Returns true if value is a RegExp
| Name | Type |
|---|---|
v | any |
boolean
Example
isRegExp(/a/) // => true
▸ isRoot(): boolean
Check if current process is running as root.
boolean
Example
isRoot() // => true
▸ isSemver(v): boolean
Returns true if the provided string is a valid semantic version
| Name | Type |
|---|---|
v | string |
boolean
Example
isSemver("0.0.0") // => true
isSemver("0.") // => false
▸ isSet(v): boolean
Returns true if value is a set
| Name | Type |
|---|---|
v | any |
boolean
Example
isSet(new Set()) // => true
▸ isString(v): boolean
Returns true if value is a string
| Name | Type |
|---|---|
v | any |
boolean
Example
isString('a') // => true
▸ isSymLink(filePath): Promise<boolean>
Returns true if path is a symlink
| Name | Type |
|---|---|
filePath | string |
Promise<boolean>
Example
isSymLink('.') // => false
▸ isSymbol(a): boolean
Returns true if value is a symbol
| Name | Type |
|---|---|
a | any |
boolean
Example
isSymbol(Symbol.for('foo')) // => true
▸ isUndefined(v): boolean
Returns true if value is undefined
| Name | Type |
|---|---|
v | any |
boolean
Example
isUndefined(undefined) // => true
▸ isValidDate(d): boolean
Returns true if the passed object is a valid Date
| Name | Type |
|---|---|
d | Date |
boolean
Example
isValidDate('1234') // => false
▸ keep(x): R
Returns an array or object with all falsey values removed
| Name | Type |
|---|---|
x | R |
Example
keep([ 'a', null, '', 2]) // => [ 'a', 2 ]
keep({ a: '', b: null, c: 2 }) // => { c: 2 }
▸ last<A>(arr): A
Returns the last element of the array
| Name |
|---|
A |
| Name | Type |
|---|---|
arr | A[] |
A
Example
last([ 1, 2, 3 ]) // => 3
▸ len(val): number
Get length of element
Works for array, object, string, set, map, and function
| Name | Type |
|---|---|
val | any |
number
Example
len('foo') // => 3
len([ 1, 2 ]) => 2
len((a, b) => a + b) // => 2
▸ lesser(a, b): number
Returns the lesser of two numbers
| Name | Type |
|---|---|
a | number |
b | number |
number
Example
lesser(1, 2) // => 1
▸ lightenOrDarken(col, amt): string
Lighten or darken a color
| Name | Type |
|---|---|
col | string |
amt | number |
string
Example
// lighten
const newCol = lightenOrDarken('#F06D06', 20)
// darken
const newCol = lightenOrDarken('#F06D06', -20)
▸ lines(str): string[]
Split a string on lines
| Name | Type |
|---|---|
str | string |
string[]
Example
lines('foo\nbar') // => [ 'foo', 'bar' ]
▸ mapObject(f, o, ctx?): AnyMap
Map for objects
| Name | Type |
|---|---|
f | (a: any, b: string, c: any) => any |
o | AnyMap |
ctx | any |
Example
const f = (a) => a + ' world'
const d = { a: 'hello', b: 'sup' }
mapObject(f, d) // => { a: 'hello world', b: 'sup world' }
▸ memoize(fn): any
A simple memoizing util
| Name | Type |
|---|---|
fn | any |
any
Example
memoize((a) => a) // => [Function]
memoize((a) => a)(1) // => 1
▸ mzero(v?): any
Get monadic empty/zero value for a type
| Name | Type |
|---|---|
v? | any |
any
Example
mzero(1) // =>
mzero([1]) // => []
▸ objectToString(v): string
toString
| Name | Type |
|---|---|
v | any |
string
Example
objectToString({}) // => '[object Object]'
▸ once<U>(fn): (...args: U[]) => U
Only calls fn once; subsequent calls just return first val
| Name |
|---|
U |
| Name | Type |
|---|---|
fn | <T>(...args: T[]) => T |
fn
▸ (...args): U
| Name | Type |
|---|---|
...args | U[] |
U
Example
const o = once(id)
o(1) // => 1
o() // => 1
o(2) // => 1
▸ open(args, opts, cb): void
Opens things. Works on Linux, Mac, and Windows
| Name | Type |
|---|---|
args | string |
opts | AnyMap |
cb | Cb |
void
Example
open('http://zacanger.com')
▸ pick(ks, o): AnyMap
pick
as it is in rambda (not ramda)
| Name | Type |
|---|---|
ks | string | string[] |
o | AnyMap |
Example
pick('a', { a: 'a', b: 'b' }) // => { a: 'a' }
pick([ 'a', 'b' ], { a: 'a', b: 'b', c: 'c' }) // => { a: 'a', b: 'b' }
▸ pipe<T>(...fns): (data: T) => T
Left to right composition
| Name |
|---|
T |
| Name | Type |
|---|---|
...fns | AnyFn[] |
fn
▸ (data): T
| Name | Type |
|---|---|
data | T |
T
Example
const addOne = (a) => a + 1
const timesTwo = (a) => a * 2
pipe(addOne, timesTwo)(2) // => 6
▸ pluck(key, arr): any[]
Simple pluck
| Name | Type |
|---|---|
key | string |
arr | any[] |
any[]
Example
pluck('a', [ { a: 'a' }, { a: 'b' } ]) // => [ 'a', 'b' ]
▸ product(nums): number
Get the product of a list of numbers
| Name | Type |
|---|---|
nums | number[] |
number
Example
product([ 1, 2, 3, 4 ]) // => 24
▸ prompt(question): Promise<string>
Create a simple prompt for the terminal
| Name | Type |
|---|---|
question | string |
Promise<string>
Example
const answer = await prompt('Do the thing')
if (answer.toLowercase() === 'y') { doTheThing() }
▸ range(a, b, step?): number[]
Range function
Takes a start and and end, and a step (defaults to 1).
This is inclusive. That is:
1..10,2 == 0,2,4,6,8,10
| Name | Type | Default value |
|---|---|---|
a | number | undefined |
b | number | undefined |
step | number | 1 |
number[]
Example
range(1, 4) // => [ 1, 2, 3, 4 ]
range(1, 10, 3) // => [ 1, 4, 7, 10 ]
▸ readJson(file): Promise<any[] | AnyMap>
Read json file and parse it
| Name | Type |
|---|---|
file | string |
Promise<any[] | AnyMap>
Example
const json = await readJson('./foo.json')
▸ reduce<A, B>(fn, initialValue, data): B
Reduce
| Name |
|---|
A |
B |
| Name | Type |
|---|---|
fn | (b: B, a: A) => B |
initialValue | B |
data | A[] |
B
Example
reduce((a, b) => a + b, 0, [ 1, 2, 3, 4 ]) // => 10
▸ removeBOM(content): string
The same as what's in Node's module (see lib/internal/module).
Remove byte order marker. This catches EF BB BF (the UTF-8 BOM)
because the buffer-to-string conversion in fs.readFileSync()
translates it to FEFF, the UTF-16 BOM.
| Name | Type |
|---|---|
content | string |
string
Example
removeBOM(someContent)
▸ replicate<A>(n, p): A[]
Generates an array of the length of the first param, filled with the second param, calling the second param if it's a function
| Name |
|---|
A |
| Name | Type |
|---|---|
n | number |
p | A | (n: number, i: number) => A |
A[]
Example
replicate(3, 10) // => [ 10, 10, 10 ]
replicate(4, (a) => a + 1) // => [ 5, 5, 5, 5 ]
▸ rgbToHex(r, g, b): string
Convert rgb to hex
| Name | Type |
|---|---|
r | number |
g | number |
b | number |
string
Example
rgbToHex(255, 255, 255) // => '#ffffff'
▸ safeGet<A>(path, fallback?): (obj: AnyMap) => undefined | null | A
Like _.get: takes an access string and an optional fallback,
then an object
| Name |
|---|
A |
| Name | Type |
|---|---|
path | string |
fallback? | A |
fn
▸ (obj): undefined | null | A
| Name | Type |
|---|---|
obj | AnyMap |
undefined | null | A
Example
safeGet('a.b.c')({ a: { b: { c: 'd' } } }) // => 'd'
safeGet('a.b.e')({ a: { b: { c: 'd' } } }) // => undefined
safeGet('a.b.e', 'f')({ a: { b: { c: 'd' } } }) // => 'f'
▸ scaleToFit(width, height, maxWidth?, maxHeight?): Object
Takes a width, height, maxWidth, and maxHeight
Returns an object that tells you the largest you can scale to
| Name | Type |
|---|---|
width | number |
height | number |
maxWidth? | number |
maxHeight? | number |
Object
| Name | Type |
|---|---|
height | number |
width | number |
Example
scaleToFit(1400, 1200, 2000, 200) // => { width: 233.33333333333331, height: 200 }
▸ shuffle<A>(arr): A[]
Randomly shuffle items in array
| Name |
|---|
A |
| Name | Type |
|---|---|
arr | A[] |
A[]
Example
shuffle([ 1, 2, 3, 4 ])
▸ sleep(ms): Promise<void>
Simple sleep.
| Name | Type |
|---|---|
ms | number |
Promise<void>
Example
const delay = await sleep(1000)
sleep(1000).then(doAThing)
▸ sortBy<A>(f, xs): A[]
Takes a sort fn and an array
Returns a sorted array
| Name |
|---|
A |
| Name | Type |
|---|---|
f | (a: A) => number |
xs | A[] |
A[]
Example
const list = [ { id: 1 }, { id: 3 }, { id: 2 } ]
sortBy(({ id }) => id, list) // => [ { id: 1 }, { id: 2 }, { id: 3 } ]
▸ sortObject(o): AnyMap
Sort an object (recursively)
| Name | Type |
|---|---|
o | AnyMap |
Example
sortObject({ b: 'c', a: 'd' }) // => { a: 'd', b: 'c' }
▸ span<A>(pred, arr): [A[], A[]]
Similar to takeWhile: returns a tuple
of all elements that pass predicate
and all elements that did not
| Name |
|---|
A |
| Name | Type |
|---|---|
pred | (a: A) => boolean |
arr | A[] |
[A[], A[]]
Example
span(lessThanThree, [ 1, 2, 3, 4 ]) // => [ [ 1, 2 ], [ 3, 4 ] ]
▸ splitAt<A>(num, arr): [A[], A[]]
Like Haskell's splitAt
splitAt n xs returns a tuple xs prefix of length n and second element is remainder of list
| Name |
|---|
A |
| Name | Type |
|---|---|
num | number |
arr | A[] |
[A[], A[]]
Example
splitAt(1, [ [ 'a', 'b' ], 'c' ]) // => [ [ [ 'a', 'b' ] ], [ 'c' ] ]
▸ store(state?): Store
A very simple store implementation (think Redux-like)
| Name | Type |
|---|---|
state | AnyMap |
Example
const state = store()
state.subscribe((next, prev) => next.foo)
state.update({ foo: 'bar' })
▸ stripAnsi(s?): string
Remove ANSI escapes from string
| Name | Type | Default value |
|---|---|---|
s | string | '' |
string
Example
stripAnsi(colorize.blue('hello')) // => 'hello'
▸ sub(ns): number
Subtract any amount of numbers
| Name | Type |
|---|---|
ns | number[] |
number
Example
sub([ 4, 3, 2, 1 ]) // => -2
▸ sum(nums): number
Sum an array of numbers
| Name | Type |
|---|---|
nums | number[] |
number
Example
sum([ 1, 2, 3, 4 ]) // => 10
▸ tail<T>(arr): T[]
All elements except first
| Name |
|---|
T |
| Name | Type |
|---|---|
arr | T[] |
T[]
Example
tail([ 1, 2, 3, 4 ]) // => [ 2, 3, 4 ]
▸ take<A>(n, a): A[]
Like Haskell's take
| Name |
|---|
A |
| Name | Type |
|---|---|
n | number |
a | A[] |
A[]
Example
take(2, [ 1, 2, 3 ]) // => [ 1, 2 ]
▸ takeLast<A>(num, arr): A[]
Takes the last n items of array
| Name |
|---|
A |
| Name | Type |
|---|---|
num | number |
arr | A[] |
A[]
Example
takeLast(2, [ 1, 2, 3, 4 ]) // => [ 3, 4 ]
▸ takeWhile<A>(pred, arr): A[]
Returns elements that pass predicate, until failure (ignores matches after failure)
| Name |
|---|
A |
| Name | Type |
|---|---|
pred | (a: A, n: number) => boolean |
arr | A[] |
A[]
Example
takeWhile((x) => x < 3, [ 1, 2, 3, 4 ]) // => [ 1, 2 ]
▸ tap(msg): <A>(a: A) => A
Log a value to console, and return that value
| Name | Type |
|---|---|
msg | string |
fn
▸ <A>(a): A
| Name |
|---|
A |
| Name | Type |
|---|---|
a | A |
A
Example
const logger = tap('This is the thing!')
logger(2) // => this is the thing 2 ; 2
▸ touch(filePath, contents?): Promise<void>
Make a file if it doesn't exist already
| Name | Type | Default value |
|---|---|---|
filePath | string | undefined |
contents | string | '' |
Promise<void>
Example
touch('foo.txt')
touch('foo.txt', 'contentx')
▸ truncate(str, limit, tail?): string
Truncate a string
| Name | Type | Default value |
|---|---|---|
str | string | undefined |
limit | number | undefined |
tail | string | '…' |
string
Example
truncate('asdf asdf asdf asdf', 4) // => 'asd…'
truncate('asdf asdf asdf asdf', 8, ' etc.') // => 'asd etc.'
▸ tryJson<T>(o): AnyMap | T
Tries to parse JSON, if is JSON
| Name |
|---|
T |
| Name | Type |
|---|---|
o | T |
AnyMap | T
Example
tryJson('[1,2]') // => [ 1, 2 ]
tryJson([ 1, 2 ]) // => [ 1, 2 ]
▸ typeOf(a): string
Enhanced typeof
| Name | Type |
|---|---|
a | any |
string
Example
typeOf('a') // => 'string'
typeOf(new Date()) // => 'date'
▸ union<A>(...xs): A[]
Get the union of any amount of arrays
| Name |
|---|
A |
| Name | Type |
|---|---|
...xs | A[][] |
A[]
Example
union([ 1, 2, 3 ], [ 2, 3, 4 ]) // => [ 1, 2, 3, 4 ]
▸ uniq<A>(arr): A[]
Uniq an array
| Name |
|---|
A |
| Name | Type |
|---|---|
arr | A[] |
A[]
Example
uniq([ 1, 1, 2, 3 ]) // => [ 1, 2, 3 ]
▸ uniqBy(el, xs): AnyMap[]
Unique an array by a string key of objects in array Returns only the values of the passed key
| Name | Type |
|---|---|
el | string |
xs | AnyMap[] |
AnyMap[]
Example
const a = [ { foo: 'foo' }, { foo: 'bar' }, { foo: 'foo' } ]
uniqBy('foo', a) // => [ { foo: 'foo' }, { foo: 'bar' } ]
▸ unless<A>(cond, fn): null | A
Call a function if the condition is falsey
| Name |
|---|
A |
| Name | Type |
|---|---|
cond | boolean |
fn | () => A |
null | A
Example
unless(() => true, false) // => true
▸ unlines(arr): string
Join an array with lines
| Name | Type |
|---|---|
arr | string[] |
string
Example
unlines([ 'foo', 'bar' ]) // => 'foo\nbar'
▸ until<T>(p, f): (...args: T[]) => T
Until p f yields result of applying f until p holds
| Name |
|---|
T |
| Name | Type |
|---|---|
p | (x: T) => boolean |
f | (...args: T[]) => T |
fn
▸ (...args): T
| Name | Type |
|---|---|
...args | T[] |
T
Example
until(equals5, increment)(2) // => 5
▸ unwords(arr): string
Join an array with spaces
| Name | Type |
|---|---|
arr | string[] |
string
Example
unwords([ 'foo', bar ]) // => 'foo bar'
▸ watch(filePath, cb): void
Watch a file for changes, and call the function
| Name | Type |
|---|---|
filePath | string |
cb | (event: string, filename: null | string) => void |
void
Example
watch('./foo', console.log)
▸ words(str): string[]
Split a string on spaces
| Name | Type |
|---|---|
str | string |
string[]
Example
words('foo bar') // => [ 'foo', 'bar' ]
▸ writeJson(path, data, indent): Promise<void>
Write JSON from a stringifiable value
| Name | Type |
|---|---|
path | string |
data | any |
indent | number |
Promise<void>
Example
await writeJson('foo.json', someObject, 4)
FAQs
Util lib
The npm package zeelib receives a total of 250 weekly downloads. As such, zeelib popularity was classified as not popular.
We found that zeelib demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 0 open source maintainers collaborating on the project.
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