fundash#

Functional utils. Heavily inspired by Lodash.

var _ = require('fundash')
 
    // get all the even numbers from the list
    getEvens = _.filter(_.isEven)
 
    // double each number from the list
  , doubleNumbers = _.map(_.double)
 
    // sum all the numbers from the list
  , sum = _.partial(_.reduce(_.sum), _, 0)
 
  , numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
 
sum(
    doubleNumbers(
        getEvens(numbers))) // [4, 8, 12, 16] -> 40
 
// or do the right way
var sumDoubleEvens = _.compose(sum, doubleNumbers, getEvents)
 
sumDoubleEvens(numbers) // [4, 8, 12, 16] -> 40

Installation

npm install fundash

Attention: This Is Not A Lodash/Underscore Replacement

To use it with Lodash/Underscore, require it to another namespace

API

• Lists
  • map
  • reduce
  • forEach
  • filter
  • some
  • every
  • none
  • pluck
  • replace
  • first
  • last
  • indexOf
• Functions
  • partial
  • curry
  • compose
  • sequence
  • propery
  • toArray
  • range
  • not
  • concat
• Operations
  • sum
  • subtract
  • multiply
  • divide
  • sumAll
  • inc
  • dec
  • double
• Checkers
  • isEven
  • isOdd
  • isNumber
  • isObject
  • isUndefined
  • isArguments
  • isEmpty
  • isString

Lists

#map()

_.map(Function [, Array])

Arguments:

• Function: accepts three arguments: item, index and list
• Array

Example:

function increment (a) {
  return a + 1
}

var list = [1, 2, 3]

_.map(increment, list) // [2, 3, 4]

var incrementItems = _.map(increment)

incrementItems(list) // [2, 3, 4]

---

#reduce()

_.reduce(Function [, Array, initial])

Arguments:

• Function: accepts four arguments: accumulator, item, index and list
• Array
• initial: *

Example:

var list = [1, 2, 3]

_.reduce(_.sum, list, 0) // 6

var sumItems = _.map(sum)

sumItems(list) // 6

---

#forEach()

_.forEach(Function [, Array])

Arguments:

• Function: accepts three arguments: item, index and list
• Array

Example:

var evens = []
  , odds = []
  , list = [1, 2, 3, 4, 5]

_.forEach(function (item) {
  var type = _.isEven(item) ? evens : odds

  type.push(item)
}, list)

// evens == [2, 4]
// odds  == [1, 3, 5]

var log = _.forEach(console.log)

log(list)
// 1 0 [1, 2, 3, 4, 5]
// 2 1 [1, 2, 3, 4, 5]
// 3 2 [1, 2, 3, 4, 5]
// 4 3 [1, 2, 3, 4, 5]
// 5 4 [1, 2, 3, 4, 5]

---

#filter()

_.filter(Function [, Array])

Arguments:

• Function: accepts three arguments: item, index and list
• Array

Example:

var list = [1, 2, 3, 4, 5]
  , evens
  , odds

evens = _.filter(_.isEven, list)
odds = _.filter(_.isOdd, list)

// evens == [2, 4]
// odds  == [1, 3, 5]

var getEvens = _.filter(_.isEven)
  , getOdds = _.filter(_.isOdd)

getEvens(list) // [2, 4]
getOdds(list)  // [1, 3, 5]

---

#some()

_.some(Function [, Array])

Arguments:

• Function: accepts three arguments: item, index and list
• Array

Example:

_.some(_.isEven, [1, 2, 3]) // true
_.some(_.isEven, [3, 5, 7]) // false
_.some(_.isOdd, [2, 3, 4])  // true

var containsEvens = _.some(_.isEven)

containsEvens([1, 2, 3]) // true

---

#every()

_.every(Function [, Array])

Arguments:

• Function: accepts three arguments: item, index and list
• Array

Example:

_.every(_.isEven, [1, 2, 3]) // flase
_.every(_.isOdd, [3, 5, 7])  // true

var onlyEvens = _.every(_.isEven)

onlyEvens([1, 2, 3]) // false

---

#none()

_.none(Function [, Array])

Arguments:

• Function: accepts three arguments: item, index and list
• Array

Example:

_.none(_.isEven, [1, 2, 3]) // flase
_.none(_.isEven, [3, 5, 7]) // true

var noEvens = _.none(_.isEven)

noEvens([1, 3, 5]) // true

---

#pluck()

_.pluck(String [, Array])

Arguments:

• String: property to be retrieved from all the items of the list
• Array

Example:

var collection = [
  { foo: 'foo' },
  { foo: 'bar' },
  { prop: 'erty' }
]

_.pluck('foo', collection) // ['foo', 'bar', undefined]

var getFoos = _.pluck('foo')

getFoos(collection) // ['foo', 'bar', undefined]

---

#replace()

_.replace(Array [, Array])

Arguments:

• Array: list of indexes to get from second Array argument
• Array

Example:

var list = [9, 8, 7, 6, 5]

_.replace([0, 2, 4], list) // [9, 7, 5]

var getFirstThreeItems = _.replace([0, 1, 2])

getFirstThreeItems(list) // [9, 8, 7]

---

#first()

_.first(Array)

Arguments:

• Array

Example:

_.first([1, 2, 3]) // 1

---

#last()

_.last(Array)

Arguments:

• Array

Example:

_.last([1, 2, 3]) // 3

---

#indexOf()

_.indexOf(value, Array)

Arguments:

• value: *: value to be searched by in the Array
• Array

Example:

_.indexOf(2, [1, 2, 3]) // 1

var foo = { bar: 'lorem' }
_.indexOf(foo, [foo]) // 0

var firstFooFrom = _.indexOf(foo)
firstFooFrom([1, 2, foo, 3, 4]) // 2

---

Functions

#partial()

_.partial(Function, Arg1 [, Arg2, ...])

Arguments:

• Function: Function whose arguments will be applied
• ArgN: Arguement(s) to be applied to the function. Arguments can be skipped using undefined or _ global

Example:

var addOne = _.partial(_.sum, 1, _)
  , addTwo = _.partial(_.sum, 2, undefined)

addOne(2) // 3
addTwo(2) // 4

---

#curry()

_.curry(Function [, argumentsSize])

Arguments:

• Function: Function to be curryied
• argumentsSize: int: quantity of arguments that Function will receive. Must be provided if Function's arity is incorrect

Example:

var curry = _.curry(function (a, b, c) {
  return [a, b, c]
})

curry(1)
curry(2)
curry(3) // [1, 2, 3]

---

#compose()

_.compose(Function, Function [, Function, ...])

Arguments:

• FunctionN: Compose a function from given functions from right to left

Example:

var sumEvens = _.compose(_.sumAll, _.filter(_.isEven))

sumEvens([1, 2, 3, 4, 5, 6, 7, 8, 9]) // 20

---

#sequence()

_.sequence(Function, Function [, Function, ...])

Arguments:

• FunctionN: Function to be executed in sequence

Example:

var sumOdds = _.sequence(_.filter(_.isOdd), _.sumAll)

sumOdds([1, 2, 3, 4, 5, 6, 7, 8, 9]) // 25

---

#propery()

_.propery(String)

Arguments:

• String: Property to be get

Example:

var getFoo = _.property('foo')

getFoo({ foo: 'bar' }) // bar

---

#toArray()

_.toArray(Arguments)

Arguments:

• Arguments: Cast arguments object to array

Example:

function foo (a, b, c) {
  var args = _.toArray(arguments)

  // args == [a, b, c]
}

---

#range()

_.range(start, end, step)

Arguments:

• start: Number: starting value
• end: Number: not including end value
• step: Number

Example:

_.range(3) // [0, 1, 2]

_.range(1, 4) // [1, 2, 3]

_.range(10, 0, -1) // [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]

_.range(1, 4, 0) // [1, 1, 1]

---

#not()

_.not(Function)

Arguments:

• Function: Function that will be negated

Example:

function foo () {
  return true
}

var notFoo = _.not(foo)

notFoo() // false

var isOdd = _.not(_.isEven)

isOdd(3) // true

_.not(true) // false

---

#concat()

_.concat(Array [, Array ...])

Arguments:

• Array

Example:

var a = [1, 2, 3]
  , b = [4, 5, 6]

_.concat(a, b) // [1, 2, 3, 4, 5, 6]

var c = [a, b, [7, 8, 9]]

_.reduce(_.concat, a) // [1, 2, 3, 4, 5, 6, 7, 8, 9]

---

Operations

#sum()

_.sum(Number, Number)

Arguments:

• Numbers: Numbers to be summed

Example:

_.sum(1, 2) // 3

---

#subtract()

_.subtract(Number, Number)

Arguments:

• Numbers: Numbers to be subtracted

Example:

_.subtract(2, 1) // 1

---

#multiply()

_.multiply(Number, Number)

Arguments:

• Numbers: Numbers to be multiplied

Example:

_.multiply(2, 2) // 4

---

#divide()

_.divide(Number, Number)

Arguments:

• Numbers: Numbers to be divided

Example:

_.divide(4, 2) // 2

---

#sumAll()

_.sumAll(Array)

Arguments:

• Array: Sum all numbers in the list. Ignores anything that is not a number

Example:

_.sumAll([1, 2, 3]) // 6

---

#inc()

_.inc(Number)

Arguments:

• Number: Number to be increased by one

Example:

_.inc(1) // 2

var incList = _.map(_.inc)

incList([0, 1, 2]) // [1, 2, 3]
incList([1, 2, 3]) // [2, 3, 4]

---

#dec()

_.dec(Number)

Arguments:

• Number: Number to be decreased by one

Example:

_.dec(1) // 2

var decList = _.map(_.dec)

decList([1, 2, 3]) // [0, 1, 2]

---

#double()

_.double(Number)

Arguments:

• Number: Number to be multiplied by 2

Example:

_.double(2) // 4

var doubleList = _.map(_.double)

doubleList([1, 2, 3]) // [2, 4, 6]

---

Checkers

#isEven()

_.isEven(Number)

Arguments:

• Number

Example:

_.isEven(1) // false
_.isEven(2) // true

---

#isOdd()

_.isOdd(Number)

Arguments:

• Number

Example:

_.isOdd(1) // true
_.isOdd(2) // false

---

#isNumber()

_.isNumber(value)

Arguments:

• value: *

Example:

_.isNumber(1)   // true
_.isNumber('1') // false

---

#isObject()

_.isObject(value)

Arguments:

• value: *

Example:

_.isObject({}) // true
_.isObject([]) // true
_.isObject('') // false

---

#isUndefined()

_.isUndefined(value)

Arguments:

• value: *

Example:

var undef
  , obj = {}

_.isUndefined(undefined) // true
_.isUndefined(void 0)    // true
_.isUndefined(undef)     // true
_.isUndefined(obj.foo)   // true
_.isUndefined('')        // false
_.isUndefined({})        // false

---

#isArguments()

_.isArguments(value)

Arguments:

• value: *

Example:

function foo () {
  return _.isArgument(arguments)
}

function bar () {
  return _.toArray(arguments)
}

foo() // true

_.isArguments(bar()) // false

---

#isEmpty()

_.isEmpty(Array|String|Object)

Arguments:

• Array|String|Object

Example:

_.isEmpty([])    // true
_.isEmpty([''])  // false
_.isEmpty('foo') // false
_.isEmpty({})    // true
_.isEmpty(null)  // true
_.isEmpty({ foo: undefined }) // false

---

#isString()

_.isEmpty(value)

Arguments:

• value: *

Example:

_.isString('')    // true
_.isString([])    // false
_.isString(null)  // false

---

TODO

• Publish to NPM
• Complete API docs
• Make wiki
• More functions (Yay!)