Dollar.swift

$ is a Swift library that provides useful functional programming helper methods without extending any built in objects.

Setup

Include the Dollar.swift into your project and import the library using import Dollar

Currently there are issues loading the library using pod 'Dollar', '~> 0.1'

Contributing

If you are interested in contributing

1. Please fork this project
2. Implement new methods or changes in the Dollar.swift file in the Classes folder
3. Write tests in DollarTests.swift file in the DollarTests folder
4. Submit a pull request.

Array Helper Methods

• $.first
• $.compact
• $.contains
• $.difference
• $.findIndex
• $.findLastIndex
• $.flatten
• $.indexOf
• $.initial
• $.intersection
• $.last
• $.lastIndexOf
• $.rest
• $.noop
• $.pull
• $.range
• $.remove
• $.sortedIndex
• $.union
• $.uniq
• $.without
• $.xor
• $.zip
• $.zipObject

Collection Helper Methods

• $.at
• $.every
• $.find
• $.min
• $.max
• $.pluck

Roadmap

More functions will be added and then ability to chain operations and lazily evaluation of chained expressions.

###Usage

$.first([1, 2, 3, 4]) as Double == 1

$.first([]) == nil

$.noop() == nil

$.compact([3, nil, 4, 5]) as NSObject[] == [3, 4, 5]

$.compact([nil, nil]) as NSObject[] == []

$.flatten([[3], 4, 5]) as Int[] == [3, 4, 5]

$.flatten([[3], "Hello", 5]) as NSObject[] == [3, "Hello", 5]

$.flatten([[[3], 4], 5]) as Int[] == [3, 4, 5]

$.indexOf(["A", "B", "C"], value: "B") == 1

$.indexOf([3, 4, 5], value: 5) == 2

$.indexOf([3, 4, 5], value: 3) == 0

$.indexOf([3, 4, 5], value: 2) == nil

$.initial([3, 4, 5]) as Int[] == [3, 4]

$.initial([3, 4, 5], numElements: 2) as Int[] == [3]

$.rest([3, 4, 5]) as Int[] == [4, 5]

$.rest([3, 4, 5], numElements: 2) as Int[] == [5]

$.last([3, 4, 5]) as Int == 5

let arr = [["age": 36], ["age": 40], ["age": 1]]
let result = $.findIndex(arr) { $0["age"] < 20 }
result == 2

let arr = [["age": 36], ["age": 40], ["age": 1]]
let result = $.findLastIndex(arr) { $0["age"] > 30 }
result == 1

$.indexOf([1, 2, 3, 1, 2, 3], value: 2) == 1

$.lastIndexOf([1, 2, 3, 1, 2, 3], value: 2) == 4

$.contains([1, 2, 3, 1, 2, 3], value: 2) == true

`$.contains([1, 2, 3, 1, 2, 3], value: 10) == false``

$.range(4) as Int[] == [0, 1, 2, 3]

$.range(1, endVal: 5) as Int[] == [1, 2, 3, 4]

$.range(0, endVal: 20, incrementBy: 5) as Int[] == [0, 5, 10, 15]

let result = $.remove([1, 2, 3, 4, 5, 6], iterator: { $0 as Int == 2 || $0 as Int == 3 })
result as Int[] == [1, 4, 5, 6]

$.sortedIndex([3, 4, 6, 10], value: 5) as Int == 2

$.sortedIndex([10, 20, 30, 50], value: 40) as Int == 3

$.without([3, 4, 5, 3, 5], values: 3, 5) as Int[] == [4]

$.without([3, 4, 5, 3, 5], values: 4) as Int[] == [3, 5, 3, 5]

$.without([3, 4, 5, 3, 5], values: 3, 4, 5) as Int[] == []

$.pull([3, 4, 5, 3, 5], values: 3, 5) as Int[] == [4]

$.pull([3, 4, 5, 3, 5], values: 4) as Int[] == [3, 5, 3, 5]

$.pull([3, 4, 5, 3, 5], values: 3, 4, 5) as Int[] == []

$.zip(["fred", "barney"], [30, 40], [true, false]) as NSObject[] == [["fred", 30, true], ["barney", 40, false]]

$.zipObject(["fred", "barney"], values: [30, 40]) as Dictionary<String, Int> == ["fred": 30, "barney": 40]

$.intersection([1, 2, 3], [5, 2, 1, 4], [2, 1]) as Int[] == [1, 2]

$.difference([1, 2, 3, 4, 5], [5, 2, 10]) as Int[] == [1, 3, 4]

$.uniq([1, 2, 1, 3, 1]) as Int[] == [1, 2, 3]

$.union([1, 2, 3], [5, 2, 1, 4], [2, 1]) as Int[] == [1, 2, 3, 4, 5]

$.xor([1, 2, 3], [5, 2, 1, 4]) as Int[] == [3, 4, 5]

$.at(["ant", "bat", "cat", "dog", "egg"], indexes: 0, 2, 4) as String[] == ["ant", "cat", "egg"]

$.every([1, 2, 3, 4], iterator: { $0 < 20 }) == true

$.every([1, 2, 3, 4], iterator: { $0 == 1 }) == false

$.find([1, 2, 3, 4], iterator: { $0 == 2 }) == 2

$.find([1, 2, 3, 4], iterator: { $0 == 10 }) == nil

$.max([1, 2, 3, 4, 2, 1]) == 4

$.min([2, 1, 2, 3, 4]) == 1

let arr : Int[] = [2, 1, 2, 3, 4]
$.contains(arr, value: $.sample(arr) as NSObject)

let arr : Dictionary<String, Int>[] = [["age": 20], ["age": 30], ["age": 40]]
$.pluck(arr, value: "age") == [20, 30, 40]