// IntExtensions.swift - Copyright 2024 SwifterSwift
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#if canImport(CoreGraphics)
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import CoreGraphics
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#endif
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#if os(macOS) || os(iOS)
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import Darwin
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#elseif os(Linux)
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import Glibc
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#endif
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// MARK: - Properties
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public extension Int {
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/// SwifterSwift: CountableRange 0..<Int.
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var countableRange: CountableRange<Int> {
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return 0..<self
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}
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/// SwifterSwift: Radian value of degree input.
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var degreesToRadians: Double {
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return Double.pi * Double(self) / 180.0
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}
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/// SwifterSwift: Degree value of radian input.
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var radiansToDegrees: Double {
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return Double(self) * 180 / Double.pi
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}
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/// SwifterSwift: UInt.
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var uInt: UInt {
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return UInt(self)
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}
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/// SwifterSwift: Double.
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var double: Double {
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return Double(self)
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}
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/// SwifterSwift: Float.
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var float: Float {
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return Float(self)
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}
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#if canImport(CoreGraphics)
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/// SwifterSwift: CGFloat.
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var cgFloat: CGFloat {
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return CGFloat(self)
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}
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#endif
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/// SwifterSwift: String formatted for values over ±1000 (example: 1k, -2k, 100k, 1kk, -5kk..).
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var kFormatted: String {
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var sign: String {
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return self >= 0 ? "" : "-"
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}
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let abs = Swift.abs(self)
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if abs == 0 {
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return "0k"
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} else if abs >= 0, abs < 1000 {
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return "0k"
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} else if abs >= 1000, abs < 1_000_000 {
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return String(format: "\(sign)%ik", abs / 1000)
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}
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return String(format: "\(sign)%ikk", abs / 100_000)
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}
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/// SwifterSwift: Array of digits of integer value.
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var digits: [Int] {
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guard self != 0 else { return [0] }
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var digits = [Int]()
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var number = abs
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while number != 0 {
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let xNumber = number % 10
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digits.append(xNumber)
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number /= 10
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}
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digits.reverse()
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return digits
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}
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/// SwifterSwift: Number of digits of integer value.
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var digitsCount: Int {
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guard self != 0 else { return 1 }
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let number = Double(abs)
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return Int(log10(number) + 1)
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}
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}
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// MARK: - Methods
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public extension Int {
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/// SwifterSwift: check if given integer prime or not. Warning: Using big numbers can be computationally expensive!
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/// - Returns: true or false depending on prime-ness.
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func isPrime() -> Bool {
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// To improve speed on latter loop :)
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if self == 2 { return true }
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guard self > 1, self % 2 != 0 else { return false }
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// Explanation: It is enough to check numbers until
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// the square root of that number. If you go up from N by one,
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// other multiplier will go 1 down to get similar result
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// (integer-wise operation) such way increases speed of operation
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let base = Int(sqrt(Double(self)))
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for int in Swift.stride(from: 3, through: base, by: 2) where self % int == 0 {
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return false
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}
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return true
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}
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/// SwifterSwift: Roman numeral string from integer (if applicable).
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///
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/// 10.romanNumeral() -> "X"
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///
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/// - Returns: The roman numeral string.
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func romanNumeral() -> String? {
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// https://gist.github.com/kumo/a8e1cb1f4b7cff1548c7
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guard self > 0 else { // there is no roman numeral for 0 or negative numbers
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return nil
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}
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let romanValues = ["M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"]
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let arabicValues = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1]
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var romanValue = ""
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var startingValue = self
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for (index, romanChar) in romanValues.enumerated() {
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let arabicValue = arabicValues[index]
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let div = startingValue / arabicValue
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for _ in 0..<div {
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romanValue.append(romanChar)
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}
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startingValue -= arabicValue * div
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}
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return romanValue
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}
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/// SwifterSwift: Rounds to the closest multiple of n.
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func roundToNearest(_ number: Int) -> Int {
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return number == 0 ? self : Int(round(Double(self) / Double(number))) * number
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}
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}
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// MARK: - Operators
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precedencegroup PowerPrecedence { higherThan: MultiplicationPrecedence }
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infix operator **: PowerPrecedence
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/// SwifterSwift: Value of exponentiation.
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///
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/// - Parameters:
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/// - lhs: base integer.
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/// - rhs: exponent integer.
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/// - Returns: exponentiation result (example: 2 ** 3 = 8).
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public func ** (lhs: Int, rhs: Int) -> Double {
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// http://nshipster.com/swift-operators/
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return pow(Double(lhs), Double(rhs))
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}
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// swiftlint:disable identifier_name
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prefix operator √
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/// SwifterSwift: Square root of integer.
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///
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/// - Parameter int: integer value to find square root for.
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/// - Returns: square root of given integer.
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public prefix func √ (int: Int) -> Double {
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// http://nshipster.com/swift-operators/
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return sqrt(Double(int))
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}
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// swiftlint:enable identifier_name
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// swiftlint:disable identifier_name
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infix operator ±
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/// SwifterSwift: Tuple of plus-minus operation.
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///
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/// - Parameters:
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/// - lhs: integer number.
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/// - rhs: integer number.
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/// - Returns: tuple of plus-minus operation (example: 2 ± 3 -> (5, -1)).
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public func ± (lhs: Int, rhs: Int) -> (Int, Int) {
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// http://nshipster.com/swift-operators/
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return (lhs + rhs, lhs - rhs)
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}
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// swiftlint:enable identifier_name
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// swiftlint:disable identifier_name
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prefix operator ±
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/// SwifterSwift: Tuple of plus-minus operation.
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///
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/// - Parameter int: integer number.
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/// - Returns: tuple of plus-minus operation (example: ± 2 -> (2, -2)).
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public prefix func ± (int: Int) -> (Int, Int) {
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// http://nshipster.com/swift-operators/
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return (int, -int)
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}
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// swiftlint:enable identifier_name
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