Rambda

Faster alternative to Ramda in just 10kB - Documentation

Argumentation

I admire Ramda as it is great library in what it does, but I used only small part of what it offers.

I wanted to optimize the size of my bundle, but I had already developed Ramda habits.

This lead me to the idea to recreate the funtionality of some Ramda methods and export that as a library.

Example use

const R = require("rambda")
const result = R.compose(
  R.filter(val => val>2),
  R.flatten,
)([ [1], [2], [3], 4])
console.log(result) // => [3,4]

Install

• Use npm i rambda for Webpack and Node.js

• For browser usage include in your HTML

https://cdnjs.cloudflare.com/ajax/libs/rambda/0.7.1/webVersion.js

Differences between Rambda and Ramda

Rambda shadows only small part of the Ramda's API.

A few things to note:

• Rambda's methods should be compatible with most of the basic Ramda's methods. For more complex and Ramda specific methods(such as R.__), you should expect a mismatch.

• Rambda's type detect async functions. The returned value is "Async"

• Rambda's map/filter work only for arrays, while Ramda's map/filter accept also objects.

• Rambda's equals doesn't protect against circular structures as Ramda.equals does.

• Rambda's path accepts both string and array as object path.

• Rambda is tested for compatability with Ramda.flip, as this method could be useful in some cases.

If you need more Ramda methods, than what Rambda offers, you may check the extended version of Rambda - Rambdax

API

add

add(a: Number, b: Number): Number

R.add(2, 3) //=>  5

adjust

adjust(replaceFn: Function, i:Number, arr:Array): Array

• Replaces i index in arr with the result of replaceFn(arr[i])

R.adjust(a => a + 1, 0, [0, 100]) //=> [1, 100]

any

any(condition: Function, arr: Array): Boolean

• Returns true if at least one member of arr returns true, when passed to the condition function

R.any(a => a * a > 8)([1, 2, 3]) //=> true
R.any(a => a * a > 10)([1, 2, 3]) //=> false

append

append(valueToAppend: any, arr: Array): Array

R.append('foo', ['bar', 'baz']) //=> ['foo', 'bar', 'baz']

compose

compose(fn1: Function, ... , fnN: Function): any

Performs right-to-left function composition

const result = R.compose(
  R.map(a => a*2)
  R.filter(val => val>2),
)([1, 2, 3, 4])
console.log(result) // => [6, 8]

contains

contains(valueToFind: any, arr: Array): Boolean

Returns true if valueToFind is part of arr

R.contains(2, [1, 2]) //=> true
R.contains(3, [1, 2]) //=> false

curry

curry(fn: Function): Function

Returns curried version of fn

const addFourNumbers = (a, b, c, d) => a + b + c + d
const curriedAddFourNumbers = R.curry(addFourNumbers)
const f = curriedAddFourNumbers(1, 2)
const g = f(3)
g(4) // => 10

defaultTo

defaultTo(defaultArgument: T, inputArgument: any): T

Returns defaultArgument if inputArgument is undefined or the type of inputArgument is different of the type of defaultArgument.

Returns inputArgument in any other case.

R.defaultTo('foo', undefined) //=> 'foo'
R.defaultTo('foo')('bar') //=> 'bar'
R.defaultTo('foo')(1) //=> 'foo'

drop

drop(howManyToDrop: Number, arrOrStr: Array|String): Array|String

Returns arrOrStr with howManyToDrop items dropped from the left

R.drop(1, ['foo', 'bar', 'baz']) //=> ['bar', 'baz']
R.drop(1, 'foo')  //=> 'oo'

dropLast

dropLast(howManyToDrop: Number, arrOrStr: Array|String): Array|String

Returns arrOrStr with howManyToDrop items dropped from the right

R.dropLast(1, ['foo', 'bar', 'baz']) //=> ['foo', 'bar']
R.dropLast(1, 'foo')  //=> 'fo'

equals

equals(a: any, b: any): Boolean

• Returns equality match between a and b

Doesn't handles cyclical data structures

R.equals(1, 1) //=> true
R.equals({}, {}) //=> false
R.equals([1, 2, 3], [1, 2, 3]) //=> true

filter

filter(filterFn: Function, arr: Array): Array

Filters arr throw boolean returning filterFn

const filterFn = a => a % 2 === 0

R.filter(filterFn, [1, 2, 3, 4]) //=> [2, 4]

find

find(findFn: Function, arr: Array): T|undefined

Returns undefined or the first element of arr satisfying findFn

const findFn = a => R.type(a.foo) === "Number"
const arr = [{foo: "bar"}, {foo: 1}]
R.find(findFn, arr) //=> {foo: 1}

findIndex

findIndex(findFn: Function, arr: Array): Number

Returns -1 or the index of the first element of arr satisfying findFn

const findFn = a => R.type(a.foo) === "Number"
const arr = [{foo: "bar"}, {foo: 1}]
R.find(findFn, arr) //=> 1

flatten

flatten(arr: Array): Array

R.flatten([ 1, [ 2, [ 3 ] ] ]
//=> [ 1, 2, 3 ]

has

has(prop: String, obj: Object): Boolean

• Returns true if obj has property prop

R.has("a", {a: 1}) //=> true
R.has("b", {a: 1}) //=> false

head

head(arrOrStr: Array|String): any

• Returns the first element of arrOrStr

R.head([1, 2, 3]) //=> 1
R.head('foo') //=> 'f'

indexOf

indexOf(valueToFind: any, arr: Array): Number

Returns -1 or the index of the first element of arr equal of valueToFind

R.indexOf(1, [1, 2]) //=> 0

init

init(arrOrStr: Array|String): Array|String

• Returns all but the last element of arrOrStr

R.init([1, 2, 3])  //=> [1, 2]
R.init('foo')  //=> 'fo'

join

join(separator: String, arr: Array): String

R.join('-', [1, 2, 3])  //=> '1-2-3'

last

last(arrOrStr: Array|String): any

• Returns the last element of arrOrStr

R.last(['foo', 'bar', 'baz']) //=> 'baz'
R.last('foo') //=> 'o'

length

length(arrOrStr: Array|String): Number

R.length([1, 2, 3]) //=> 3

map

map(mapFn: Function, arr: Array): Array

Returns the result of looping through arr with mapFn

const mapFn = x => x * 2;
R.map(mapFn, [1, 2, 3]) //=> [2, 4, 6]

match

map(regExpression: Regex, str: String): Array

R.match(/([a-z]a)/g, 'bananas') //=> ['ba', 'na', 'na']

merge

merge(a: Object, b: Object)

Returns result of Object.assign({}, a, b)

R.merge({ 'foo': 0, 'bar': 1 }, { 'foo': 7 })
//=> { 'foo': 7, 'bar': 1 }

omit

omit(propsToOmit: Array, obj: Object): Object

• Returns a partial copy of an obj with omitting propsToOmit

R.omit(['a', 'd'], {a: 1, b: 2, c: 3}) //=> {b: 2, c: 3}

path

path(pathToSearch: Array|String, obj: Object): any

• Retrieve the value at pathToSearch in object obj

R.path('a.b', {a: {b: 2}}) //=> 2
R.path(['a', 'b'], {a: {b: 2}}) //=> 2
R.path(['a', 'c'], {a: {b: 2}}) //=> undefined

partialCurry

partialCurry(fn: Function|Async, a: Object, b: Object): Function|Promise

When called with function fn and first set of input a, it will return a function.

This function will wait to be called with second set of input b and it will invoke fn with the merged object of a over b.

fn can be asynchronous function. In that case a Promise holding the result of fn is returned.

See the example below:

const fn = ({a, b, c}) => {
  return (a * b) + c
}
const curried = R.partialCurry(fn, {a: 2})
curried({b: 3, c: 10}) //=> 16

• Note that partialCurry is method specific for Rambda and the method is not part of Ramda's API

• You can read my argumentation for creating partialCurry here

pick

pick(propsToPick: Array, obj: Object): Object

• Returns a partial copy of an obj containing only propsToPick properties

R.pick(['a', 'c'], {a: 1, b: 2}) //=> {a: 1}

pluck

pluck(property: String, arr: Array): Array

• Returns list of the values of property taken from the objects in array of objects arr

R.pluck('a')([{a: 1}, {a: 2}, {b: 3}]) //=> [1, 2]

prepend

prepend(valueToPrepend: any, arr: Array): Array

R.prepend('foo', ['bar', 'baz']) //=> ['foo', 'bar', 'baz']

prop

prop(propToFind: String, obj: Object): any

Returns undefined or the value of property propToFind in obj

R.prop('x', {x: 100}) //=> 100
R.prop('x', {a: 1}) //=> undefined

propEq

propEq(propToFind: String, valueToMatch: any, obj: Object): Boolean

Returns true if obj has property propToFind and its value is equal to valueToMatch

const propToFind = "foo"
const valueToMatch = 0
R.propEq(propToFind, valueToMatch)({foo: 0}) //=> true
R.propEq(propToFind, valueToMatch)({foo: 1}) //=> false

range

range(start: Number, end: Number): Array

• Returns a array of numbers from start(inclusive) to end(exclusive)

R.range(0, 2)   //=> [0, 1]

reduce

reduce(iteratorFn: Function, accumulator: any, array: Array): any

• Returns a single item by iterating through the list, successively calling the iterator function iteratorFn and passing it an accumulator value and the current value from the array, and then passing the result to the next call.

The iterator function behaves like the native callback of the Array.prototype.reduce method.

const iteratorFn = (acc, val) => acc + val
R.reduce(iteratorFn, 1, [1, 2, 3])   //=> 7

repeat

repeat(valueToRepeat: T, num: Number): Array

R.repeat('foo', 2) //=> ['foo', 'foo']

replace

replace(strOrRegex: String|Regex, replacer: String, str: String): String

Replace strOrRegex found in str with replacer

R.replace('foo', 'bar', 'foo foo') //=> 'bar foo'
R.replace(/foo/, 'bar', 'foo foo') //=> 'bar foo'
R.replace(/foo/g, 'bar', 'foo foo') //=> 'bar bar'

sort

sort(sortFn: Function, arr: Array): Array

Returns copy of arr sorted by sortFn

sortFn must return Number

const sortFn = (a, b) => a - b
R.sort(sortFn, [3, 1, 2]) //=> [1, 2, 3]

sortBy

sortBy(sortFn: Function, arr: Array): Array

Returns copy of arr sorted by sortFn

sortFn must return value for comparison

const sortFn = obj => obj.foo
R.sortBy(sortFn, [
  {foo: 1},
  {foo: 0}
])
//=> [{foo: 0}, {foo: 1}]

split

split(separator: String, str: String): Array

R.split('-', 'a-b-c') //=> ['a', 'b', 'c']

splitEvery

splitEvery(sliceLength: Number, arrOrString: Array|String): Array

• Splits arrOrStr into slices of sliceLength

R.splitEvery(2, [1, 2, 3]) //=> [[1, 2], [3]]
R.splitEvery(3, 'foobar') //=> ['foo', 'bar']

subtract

subtract(a: Number, b: Number): Number

Returns a minus b

R.subtract(3, 1) //=> 2

tail

tail(arrOrStr: Array|String): Array|String

• Returns all but the first element of arrOrStr

R.tail([1, 2, 3])  //=> [2, 3]
R.tail('foo')  //=> 'oo'

take

take(num: Number, arrOrStr: Array|String): Array|String

• Returns the first num elements of arrOrStr

R.take(1, ['foo', 'bar']) //=> ['foo']
R.take(2, ['foo']) //=> 'fo'

takeLast

takeLast(num: Number, arrOrStr: Array|String): Array|String

• Returns the last num elements of arrOrStr

R.takeLast(1, ['foo', 'bar']) //=> ['bar']
R.takeLast(2, ['foo']) //=> 'oo'

test

test(regExpression: Regex, str: String): Boolean

• Determines whether str matches regExpression

R.test(/^f/, 'foo') //=> true
R.test(/^f/, 'bar') //=> false

toLower

toLower(str: String): String

R.toLower('FOO') //=> 'foo'

toUpper

toUpper(str: String): String

R.toUpper('foo') //=> 'FOO'

trim

trim(str: String): String

R.trim('  foo  ') //=> 'foo'

type

type(a: any): String

R.type(() => {}) //=> "Function"
R.type(async () => {}) //=> "Async"
R.type([]) //=> "Array"
R.type({}) //=> "Object"
R.type('s') //=> "String"
R.type(1) //=> "Number"
R.type(false) //=> "Boolean"
R.type(null) //=> "Null"
R.type(/[A-z]/) //=> "RegExp"

uniq

uniq(arr: Array): Array

• Returns a new array containing only one copy of each element in arr

R.uniq([1, 1, 2, 1]) //=> [1, 2]
R.uniq([1, '1'])     //=> [1, '1']

update

update(i: Number, replaceValue: any, arr: Array): Array

• Returns a new copy of the arr with the element at i index replaced with replaceValue

R.update(0, "foo", ['bar', 'baz']) //=> ['foo', baz]

values

values(obj: Object): Array

• Returns array with of all values in obj

R.values({a: 1, b: 2}) //=> [1, 2]

---

Benchmark

Flowtype

I haven't tested it fully, but the partial test shows that Ramda definitions can be used.

You need to replace declare module ramda with declare module rambda on line 10 and store the file as rambda.js in your flow-typed folder

More info

Changelog

• 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

Projects using Rambda

• I Learn Smarter

• json-validity

• log-fn

• nightmare-helper

• string-fn

• watch-fn

Articles about Rambda

• Interview with Dejan Totef at SurviveJS blog
• Argumentation of Rambda's curry method