Add ArrayExtension

Sources/OversizeCore/Extensions/Swift/Array+Extension.swift

@@ -142,3 +142,33 @@ extension Array: RawRepresentable where Element: Codable {
         return result
     }
 }
+
+public extension BidirectionalCollection where Iterator.Element: Equatable {
+    func after(_ item: Iterator.Element, loop: Bool = false) -> Element? {
+        if let itemIndex = firstIndex(of: item) {
+            let lastItem: Bool = (index(after: itemIndex) == endIndex)
+            if loop, lastItem {
+                return first
+            } else if lastItem {
+                return nil
+            } else {
+                return self[index(after: itemIndex)]
+            }
+        }
+        return nil
+    }
+
+    func before(_ item: Iterator.Element, loop: Bool = false) -> Element? {
+        if let itemIndex = firstIndex(of: item) {
+            let firstItem: Bool = (itemIndex == startIndex)
+            if loop, firstItem {
+                return last
+            } else if firstItem {
+                return nil
+            } else {
+                return self[index(before: itemIndex)]
+            }
+        }
+        return nil
+    }
+}