add suffix while method

Author: michiboo

Sources/Algorithms/Suffix.swift

@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Algorithms open source project
+//
+// Copyright (c) 2020 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Suffix(while:)
+//===----------------------------------------------------------------------===//
+
+extension BidirectionalCollection {
+  @inlinable
+  public __consuming func Suffix(while predicate: (Element) throws -> Bool
+  ) rethrows -> [Element] {
+   var result = ContiguousArray<Element>()
+   self.reverse()
+    for element in self {
+      guard try predicate(element) else {
+        break
+      }
+      result.append(element)
+    }
+    result.reverse()
+    return Array(result)
+  }
+}