Initial Commit

WOKA/Helpers/StringSubScript.swift

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+//
+//  StringSubScript.swift
+//  WOKA
+//
+//  Created by MacBook Pro on 29/04/24.
+//
+
+import Foundation
+
+
+/*
+ The first subscript allows you to access an element at a specific offset in the string.
+ The next two subscripts allow you to get a subsequence using a range (open or closed).
+ The last three subscripts handle partial ranges, providing a subsequence from the start, up to a specified index, or from a specified index to the end.
+ */
+
+import Foundation
+extension StringProtocol {
+    subscript(_ offset: Int)                     -> Element     { self[index(startIndex, offsetBy: offset)] }
+    subscript(_ range: Range<Int>)               -> SubSequence { prefix(range.lowerBound+range.count).suffix(range.count) }
+    subscript(_ range: ClosedRange<Int>)         -> SubSequence { prefix(range.lowerBound+range.count).suffix(range.count) }
+    subscript(_ range: PartialRangeThrough<Int>) -> SubSequence { prefix(range.upperBound.advanced(by: 1)) }
+    subscript(_ range: PartialRangeUpTo<Int>)    -> SubSequence { prefix(range.upperBound) }
+    subscript(_ range: PartialRangeFrom<Int>)    -> SubSequence { suffix(Swift.max(0, count-range.lowerBound)) }
+}
+
+extension LosslessStringConvertible {
+    var string: String { .init(self) }
+}
+
+extension BidirectionalCollection {
+    subscript(safe offset: Int) -> Element? {
+        if offset < 0 { return nil }
+        guard !isEmpty, let i = index(startIndex, offsetBy: offset, limitedBy: index(before: endIndex)) else { return nil }
+        return self[i]
+    }
+}
+
+/*
+let test = "Hello USA 🇺🇸!!! Hello Brazil 🇧🇷!!!"
+test[safe: 10]   // "🇺🇸"
+test[11]   // "!"
+test[10...]   // "🇺🇸!!! Hello Brazil 🇧🇷!!!"
+test[10..<12]   // "🇺🇸!"
+test[10...12]   // "🇺🇸!!"
+test[...10]   // "Hello USA 🇺🇸"
+test[..<10]   // "Hello USA "
+test.first   // "H"
+test.last    // "!"
+
+// Subscripting the Substring
+ test[...][...3]  // "Hell"
+
+// Note that they all return a Substring of the original String.
+// To create a new String from a substring
+test[10...].string  // "🇺🇸!!! Hello Brazil 🇧🇷!!!"
+*/