101.md

title	category	updated	intro
101	JavaScript libraries	2017-09-21	[101](https://www.npmjs.com/package/101) is a JavaScript library for dealing with immutable data in a functional manner.

Usage

const isObject = require('101/isObject')
isObject({}) // → true

Every function is exposed as a module.

See: 101

Type checking

isObject({})
isString('str')
isRegExp(/regexp/)
isBoolean(true)
isEmpty({})
isfunction(x => x)
isInteger(10)
isNumber(10.1)
instanceOf(obj, 'string')

Objects

{: .-three-column}

Example

{: .-prime}

let obj = {}

Update

obj = put(obj, 'user.name', 'John')
// → { user: { name: 'John' } }

Read

pluck(name, 'user.name')
// → 'John'

Delete

obj = del(obj, 'user')
// → { }

Getting

pluck(state, 'user.profile.name')

pick(state, ['user', 'ui'])
pick(state, /^_/)

pluck returns values, pick returns subsets of objects.

See: pluck, pick

Setting

put(state, 'user.profile.name', 'john')

See: put

Deleting

del(state, 'user.profile')
omit(state, ['user', 'data'])

omit is like del, but supports multiple keys to be deleted.

See: omit, del

Keypath check

hasKeypaths(state, ['user'])
hasKeypaths(state, { 'user.profile.name': 'john' })

See: hasKeypaths

Get values

values(state)

Functions

Simple functions

| and(x, y) | x && y | | or(x, y) | x || y | | xor(x, y) | !(!x && !y) && !(x && y) | | equals(x, y) | x === y | | exists(x) | !!x | | not(x) | !x |

Useful for function composition.

See: and, equals, exists

Composition

compose(f, g)       // x => f(g(x))
curry(f)            // x => y => f(x, y)
flip(f)             // f(x, y) --> f(y, x)

See: compose, curry, flip

And/or

passAll(f, g)       // x => f(x) && g(x)
passAny(f, g)       // x => f(x) || g(x)

See: passAll, passAny

Converge

converge(and, [pluck('a'), pluck('b')])(x)

// → and(pluck(x, 'a'), pluck(x, 'b'))

See: converge

Arrays

Finding

find(list, x => x.y === 2)
findIndex(list, x => ...)
includes(list, 'item')
last(list)

find(list, hasProps('id'))

Grouping

groupBy(list, 'id')
indexBy(list, 'id')

Examples

Function composition

isFloat = passAll(isNumber, compose(isInteger, not))
// n => isNumber(n) && not(isInteger(n))

function doStuff (object, options) { ... }

doStuffForce = curry(flip(doStuff))({ force: true })

Reference

• https://github.com/tjmehta/101