
Product
Socket for Jira Is Now Available
Socket for Jira lets teams turn alerts into Jira tickets with manual creation, automated ticketing rules, and two-way sync.
crocks is a collection of popular Algebraic Data Types (ADTs) that are all
the rage in functional programming. You have heard of things
like Maybe and Either and heck maybe even IO, that is what these are. The
main goal of crocks is to curate and provide not only a common interface
between each type (where possible of course), but also provide all of the helper
functions needed to hit the ground running.
crocks is available from npm and is just a shell command away. All you need
to do is run the following to save it as a dependency in your current project
folder:
$ npm install crocks -S
There are many options to use crocks to suit the needs of your, projects. When
used on the backend or in an environment where size is not a big concern, the
entire lib can be brought in and the various elements can be either be plucked
off of or referenced by the namespace.
For those cases where size matters, like in the case of frontend bundle building, the individual entities can be brought in. This will ensure that your finished bundles include only what is needed for your application/program.
For using the latter case, refer to the desired function's documentation to find the path in which it resides.
crocks library (CommonJS)// namespace entire suite to crocks variable
const crocks = require('crocks')
// pluck anything that does not require name-spacing
const { safe, isNumber } = crocks
// still requires entire object, but removes name-spacing
const { and, liftA2 } = require('crocks')
// divide :: Number -> Number
const divide =
x => y => x / y
// safeNumber :: a -> Maybe Number
const safeNumber =
safe(isNumber)
// notZero :: a -> Maybe Number
const notZero = safe(
and(isNumber, x => x !== 0)
)
// safeDivide:: a -> Maybe Number
const safeDivide = crocks.curry(
(x, y) => liftA2(divide, safeNumber(x), notZero(y))
)
safeDivide(20, 0)
//=> Nothing
safeDivide(20, 5)
//=> Just 4
safeDivide('number', 5)
//=> Nothing
crocks library (JS Modules)// namespace entire suite to crocks variable
import crocks from 'crocks'
// still imports entire object, but removes name-spacing
import { and, liftA2 } from 'crocks'
// pluck anything that does not require name-spacing
const { safe, isNumber } = crocks
// divide :: Number -> Number
const divide =
x => y => x / y
// safeNumber :: a -> Maybe Number
const safeNumber =
safe(isNumber)
// notZero :: a -> Maybe Number
const notZero = safe(
and(isNumber, x => x !== 0)
)
// safeDivide:: a -> Maybe Number
const safeDivide = crocks.curry(
(x, y) => liftA2(divide, safeNumber(x), notZero(y))
)
safeDivide(20, 0)
//=> Nothing
safeDivide(20, 5)
//=> Just 4
safeDivide('number', 5)
//=> Nothing
// require in each entity directly
const and = require('crocks/logic/and')
const curry = require('crocks/helpers/curry')
const isNumber = require('crocks/predicates/isNumber')
const liftA2 = require('crocks/helpers/liftA2')
const safe = require('crocks/Maybe/safe')
// divide :: Number -> Number
const divide =
x => y => x / y
// safeNumber :: a -> Maybe Number
const safeNumber =
safe(isNumber)
// notZero :: a -> Maybe Number
const notZero = safe(
and(isNumber, x => x !== 0)
)
// safeDivide:: a -> Maybe Number
const safeDivide = curry(
(x, y) => liftA2(divide, safeNumber(x), notZero(y))
)
safeDivide(20, 0)
//=> Nothing
safeDivide(20, 5)
//=> Just 4
safeDivide('number', 5)
//=> Nothing
// import in each entity directly
import and from 'crocks/logic/and'
import curry from 'crocks/helpers/curry'
import isNumber from 'crocks/predicates/isNumber'
import liftA2 from 'crocks/helpers/liftA2'
import safe from 'crocks/Maybe/safe'
// divide :: Number -> Number
const divide =
x => y => x / y
// safeNumber :: a -> Maybe Number
const safeNumber =
safe(isNumber)
// notZero :: a -> Maybe Number
const notZero = safe(
and(isNumber, x => x !== 0)
)
// safeDivide:: a -> Maybe Number
const safeDivide = curry(
(x, y) => liftA2(divide, safeNumber(x), notZero(y))
)
safeDivide(20, 0)
//=> Nothing
safeDivide(20, 5)
//=> Just 4
safeDivide('number', 5)
//=> Nothing
There are (8) classifications of "things" included in this library:
Crocks: These are the ADTs that this library is centered around.
They are all Functor based Data Types that provide different computational
contexts for working in a more declarative, functional flow. For the most part,
a majority of the other bits in crocks exist to serve these ADTs.
Monoids: These helpful ADTs are in a class of their own, not
really Functors in their own right (although some can be), they are still very
useful in our everyday programming needs. Ever need to sum a list of numbers or
mix a mess of objects together? This is were you will find the ADTs you need to
do that.
Combinators: A collection of functions that are used for
working with other functions. These do things like compose (2) functions
together, or flip arguments on a function. They typically either take a
function, return a function or a bit a both. These are considered the glue that
holds the mighty house of crocks together and a valuable aid in writing
reusable code.
Helper Functions: All other support functions that are either convenient versions of combinators or not even combinators at all cover this group.
Logic Functions: A helpful collection of logic based
functions. All of these functions work with either predicate functions or
instances of Pred and let you combine them in some very interesting ways.
Predicate Functions: A helpful collection of predicate functions to get you started.
Point-free Functions: Wanna use these ADTs in a way
that you never have to reference the actual data being worked on? Well here is
where you will find all of these functions to do that. For every algebra
available on both the Crocks and Monoids there is a function here.
Transformation Functions: All the functions found
here are used to transform from one type to another, naturally. These come are
handy in situations where you have functions that return one type (like
an Either), but are working in a context of another (say Maybe). You would
like to compose these, but in doing so will result in a nesting that you will
need to account for for the rest of your flow.
Thanks goes to these wonderful people (emoji key):
FAQs
A collection of well known Algebraic Datatypes for your utter enjoyment.
We found that crocks demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
Did you know?

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.

Product
Socket for Jira lets teams turn alerts into Jira tickets with manual creation, automated ticketing rules, and two-way sync.

Company News
Socket won two 2026 Reppy Awards from RepVue, ranking in the top 5% of all sales orgs. AE Alexandra Lister shares what it's like to grow a sales career here.

Security News
NIST will stop enriching most CVEs under a new risk-based model, narrowing the NVD's scope as vulnerability submissions continue to surge.