Dactyloidae iOS initial commit

mobile/ios/Shared/Extensions/ArrayExtensions.swift

@@ -0,0 +1,70 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import Foundation
+
+public extension Array where Element: Comparable {
+    func sameElements(_ arr: [Element]) -> Bool {
+        guard self.count == arr.count else { return false }
+        let sorted = self.sorted(by: <)
+        let arrSorted = arr.sorted(by: <)
+        for elements in sorted.zip(arrSorted) where elements.0 != elements.1 {
+            return false
+        }
+        return true
+    }
+}
+
+public extension Array {
+
+    func find(_ f: (Iterator.Element) -> Bool) -> Iterator.Element? {
+        for x in self {
+            if f(x) {
+                return x
+            }
+        }
+        return nil
+    }
+    
+    func contains(_ x: Element, f: (Element, Element) -> Bool) -> Bool {
+        for y in self {
+            if f(x, y) {
+                return true
+            }
+        }
+        return false
+    }
+
+    // Performs a union operator using the result of f(Element) as the value to base uniqueness on.
+    func union<T: Hashable>(_ arr: [Element], f: ((Element) -> T)) -> [Element] {
+        let result = self + arr
+        return result.unique(f)
+    }
+
+    // Returns unique values in an array using the result of f()
+    func unique<T: Hashable>(_ f: ((Element) -> T)) -> [Element] {
+        var map: [T: Element] = [T: Element]()
+        return self.flatMap { a in
+            let t = f(a)
+            if map[t] == nil {
+                map[t] = a
+                return a
+            } else {
+                return nil
+            }
+        }
+    }
+
+}
+
+public extension Sequence {
+    func every(_ f: (Self.Iterator.Element) -> Bool) -> Bool {
+        for x in self {
+            if !f(x) {
+                return false
+            }
+        }
+        return true
+    }
+}