[destructuring] Implement initializers in patterns.

src/parser.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.
 
 #ifndef V8_PARSER_H_
 #define V8_PARSER_H_
 
 #include "src/allocation.h"
 #include "src/ast.h"
 #include "src/compiler.h"  // TODO(titzer): remove this include dependency
@@ skipping 986 matching lines @@
 #undef DECLARE_VISIT
     virtual void Visit(AstNode* node) override;
 
     void RecurseIntoSubpattern(AstNode* pattern, Expression* value) {
       Expression* old_value = current_value_;
       current_value_ = value;
       pattern->Accept(this);
       current_value_ = old_value;
     }
 
+    Variable* CreateTemp(Expression* value);
+
     AstNodeFactory* factory() const { return descriptor_->parser->factory(); }
     AstValueFactory* ast_value_factory() const {
       return descriptor_->parser->ast_value_factory();
     }
     bool inside_with() const { return descriptor_->parser->inside_with(); }
     Zone* zone() const { return descriptor_->parser->zone(); }
+    Scope* TemporaryDeclarationScope() const {

[rossberg, 2015/05/18 16:17:19]

Nit: is there a strong reason to say "Temporary" here?

[Dmitry Lomov (no reviews), 2015/05/18 17:31:22]

Yes, it is a declaration scope for temporary variables (as opposed to
declaration scope for the variables pattern matcher declares, which is
controlled by DeclarationDescriptor and ultimately by whether this is a lexical
declaration or not). However I inlined into CreateTempVar.

+      return descriptor_->parser->scope_->DeclarationScope();
+    }
 
     Expression* pattern_;
     int initializer_position_;
     Block* block_;
     const DeclarationDescriptor* descriptor_;
     ZoneList<const AstRawString*>* names_;
     Expression* current_value_;
     bool* ok_;
   };
 
@@ skipping 237 matching lines @@
 }
 
 
 Expression* ParserTraits::SpreadCallNew(
     Expression* function, ZoneList<v8::internal::Expression*>* args, int pos) {
   return parser_->SpreadCallNew(function, args, pos);
 }
 } }  // namespace v8::internal
 
 #endif  // V8_PARSER_H_