all-user / swiftcombination

Ruby's "combination", "permutation" in Swift.

SwiftCombination

Ruby's "combination", "permutation" in Swift.

let combos = combination([0, 1, 2], length: 2)
print(combos) // => [[0, 1], [0, 2], [1, 2]]

let rCombos = repeatedCombination([0, 1, 2], length: 2)
print(rCombos) // => [[0, 0], [0, 1], [0, 2], [1, 1], [1, 2], [2, 2]]



let a = [1, 2, 3, 4]

print(combination(a, length: 1)) // => [[1], [2], [3], [4]]
print(combination(a, length: 2)) // => [[1, 2], [1, 3], [1, 4], [2, 3], [2, 4], [3, 4]]
print(combination(a, length: 3)) // => [[1, 2, 3], [1, 2, 4], [1, 3, 4], [2, 3, 4]]
print(combination(a, length: 4)) // => [[1, 2, 3, 4]]
print(combination(a, length: 0)) // => [[]]
print(combination(a, length: 5)) // => []



// Array method

print(a.combination(3))
// => [[1, 2, 3], [1, 2, 4], [1, 3, 4], [2, 3, 4]]



// with closure

a.combination(2){ print($0) }
// =>
// [1, 2]
// [1, 3]
// [1, 4]
// [2, 3]
// [2, 4]
// [3, 4]



let chrs = ["h", "e", "l", "o", "!"]
chrs.repeatedCombination(6){ combo in
    if combo.joined(separator: "") == "hello!" { print(combo) }
}
// => [h, e, l, l, o, !]



// => permutation

var chars = ["a", "c", "t"]

//chars.permutation(3){ println($0 }
// => shorthand
chars.permutation{ print($0) }
// =>
// [a, c, t]
// [a, t, c]
// [c, a, t]
// [c, t, a]
// [t, a, c]
// [t, c, a]



// repeated permutation

[0, 1].repeatedPermutation(4){ print($0) }
// =>
// [0, 0, 0, 0]
// [0, 0, 0, 1]
// [0, 0, 1, 0]
// [0, 0, 1, 1]
// [0, 1, 0, 0]
// [0, 1, 0, 1]
// [0, 1, 1, 0]
// [0, 1, 1, 1]
// [1, 0, 0, 0]
// [1, 0, 0, 1]
// [1, 0, 1, 0]
// [1, 0, 1, 1]
// [1, 1, 0, 0]
// [1, 1, 0, 1]
// [1, 1, 1, 0]
// [1, 1, 1, 1]

Installation

Swift Package Manager

Create a Package.swift file.

import PackageDescription

let package = Package(
    name: "FooProject",
    targets: [],
    dependencies: [
        .Package(url: "https://github.com/all-user/SwiftCombination.git", versions: "0.2.0"..<"0.3.0")
    ]
)

And, Use as follows.

import SwiftCombination

swiftcombination's Issues

permutation encountered argument type error when given a closure

class FooBar {
    static func baz() {
        permutation([0, 1]) { print($0) } // Cannot convert value of type '(Any) -> ()' to expected argument type 'Int?'
    }
}

class FooBar {
    static func baz() {
        permutation([0, 1], length: 2) { print($0) } // Extra argument 'length' in call
    }
}

repeatedPermutation encountered argument type error when given a closure

class FooBar {
    static func baz() {
        repeatedPermutation([0, 1]) { print($0) } // Cannot convert value of type '(Any) -> ()' to expected argument type 'Int?'
    }
}

class FooBar {
    static func baz() {
        repeatedPermutation([0, 1], length: 2) { print($0) } // Extra argument 'length' in call
    }
}

What is the license of this library?

I'd like to use this library. But there is no license file.

permutation with nonfull-length is not correct

let a = [1, 2, 3]
let p = a.permutation(2)
print(p)

//output: [[1, 2], [2, 1], [1, 2], [2, 1], [1, 2], [2, 1]]

permutation encountered 'Index out of range' error when length greater than array.count

func testArgLengthGreaterThanCollectionLength() {
    let actual = permutation([0, 1], length: 3)
    XCTAssertTrue(actual.isEmpty)
}
// fatal error: Index out of range

combination, repeatedCombination, repeatedPermutation should not be zero length arguments

Theses methods in Ruby are not allow zero length arguments.

arr = [0,1]
arr.combination
# => ArgumentError: wrong number of arguments (given 0, expected 1)
arr.repeated_combination
# => ArgumentError: wrong number of arguments (given 0, expected 1)
arr.repeated_permutation
# => ArgumentError: wrong number of arguments (given 0, expected 1)
arr.permutaion
# => [[0, 1], [1, 0]]
# permutation allow zero length argument.