Add {Map,Set}::FromArray to the API

include/v8.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
@@ skipping 2958 matching lines @@
  public:
   size_t Size() const;
 
   /**
    * Returns an array of [key, value] arrays representing the contents
    * of this Map.
    */
   Local<Array> AsArray() const;
 
   /**
-   * Creates a new Map.
+   * Creates a new empty Map.
    */
   static Local<Map> New(Isolate* isolate);
 
+  /**
+   * Creates a new Map containing the elements of array, which must be comprised
+   * of [key, value] arrays.
+   * Guaranteed to be side-effect free if the array contains no holes.

[arv (Not doing code reviews), 2015/05/26 16:37:40]

If the main use case is structured clone we could do an array where the keys and
values are interleaved.

[k0, v0, k1, v1, ... kn, vn]

[adamk, 2015/05/26 17:27:44]

Let's leave this for a later round where we optimize the performance. For now
I'd rather leave this symmetric with AsArray().

+   */
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Map> FromArray(Local<Context> context,
+                                                         Local<Array> array);
+
   V8_INLINE static Map* Cast(Value* obj);
 
  private:
   Map();
   static void CheckCast(Value* obj);
 };
 
 
 /**
  * An instance of the built-in Set constructor (ECMA-262, 6th Edition, 23.2.1).
  */
 class V8_EXPORT Set : public Object {
  public:
   size_t Size() const;
 
   /**
    * Returns an array of the keys in this Set.
    */
   Local<Array> AsArray() const;
 
   /**
-   * Creates a new Set.
+   * Creates a new empty Set.
    */
   static Local<Set> New(Isolate* isolate);
 
+  /**
+   * Creates a new Set containing the items in array.
+   * Guaranteed to be side-effect free if the array contains no holes.
+   */
+  static V8_WARN_UNUSED_RESULT MaybeLocal<Set> FromArray(Local<Context> context,
+                                                         Local<Array> array);
+
   V8_INLINE static Set* Cast(Value* obj);
 
  private:
   Set();
   static void CheckCast(Value* obj);
 };
 
 
 template<typename T>
 class ReturnValue {
@@ skipping 5158 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_