Simplify AST by extending LetNode and replace CommaNode.

runtime/vm/ast.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_AST_H_
 #define VM_AST_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
@@ skipping 38 matching lines @@
   V(LoadLocalNode, "load local")                                               \
   V(StoreLocalNode, "store local")                                             \
   V(LoadInstanceFieldNode, "load field")                                       \
   V(StoreInstanceFieldNode, "store field")                                     \
   V(LoadStaticFieldNode, "load static field")                                  \
   V(StoreStaticFieldNode, "store static field")                                \
   V(LoadIndexedNode, "load indexed")                                           \
   V(StoreIndexedNode, "store indexed")                                         \
   V(SequenceNode, "seq")                                                       \
   V(LetNode, "let")                                                            \
-  V(CommaNode, "comma")                                                        \
   V(CatchClauseNode, "catch clause block")                                     \
   V(TryCatchNode, "try catch block")                                           \
   V(ThrowNode, "throw")                                                        \
   V(InlinedFinallyNode, "inlined finally")                                     \
 
 
 #define DEFINE_FORWARD_DECLARATION(type, name) class type;
 NODE_LIST(DEFINE_FORWARD_DECLARATION)
 #undef DEFINE_FORWARD_DECLARATION
 
@@ skipping 105 matching lines @@
 
  private:
   LocalScope* scope_;
   GrowableArray<AstNode*> nodes_;
   SourceLabel* label_;
 
   DISALLOW_COPY_AND_ASSIGN(SequenceNode);
 };
 
 
-// Comma node represents a pair of expressions evaluated in sequence
-// and return the value of the second expression.
-class CommaNode : public AstNode {
- public:
-  CommaNode(intptr_t token_pos,
-            AstNode* first,
-            AstNode* second)
-      : AstNode(token_pos),
-        first_(first),
-        second_(second) { }
-
-  AstNode* first() const { return first_; }
-  AstNode* second() const { return second_; }
-
-  void VisitChildren(AstNodeVisitor* visitor) const {
-    first_->Visit(visitor);
-    second_->Visit(visitor);
-  }
-
-  DECLARE_COMMON_NODE_FUNCTIONS(CommaNode);
-
- private:
-  AstNode* first_;
-  AstNode* second_;
-
-  DISALLOW_COPY_AND_ASSIGN(CommaNode);
-};
-
-
 class CloneContextNode : public AstNode {
  public:
   explicit CloneContextNode(intptr_t token_pos)
     : AstNode(token_pos) {
   }
 
   virtual void VisitChildren(AstNodeVisitor* visitor) const { }
 
   DECLARE_COMMON_NODE_FUNCTIONS(CloneContextNode);
 
@@ skipping 72 matching lines @@
 
 class LetNode : public AstNode {
  public:
   explicit LetNode(intptr_t token_pos);
 
   LocalVariable* TempAt(intptr_t i) const { return vars_[i]; }
   AstNode* InitializerAt(intptr_t i) const { return initializers_[i]; }
 
   LocalVariable* AddInitializer(AstNode* node);
 
+  const GrowableArray<AstNode*>& nodes() const { return nodes_; }
+
+  void AddNode(AstNode* node) { nodes_.Add(node); }
+
   intptr_t num_temps() const {
     return vars_.length();
   }
 
-  AstNode* body() const { return body_; }
-  void set_body(AstNode* node) { body_ = node; }
-
   void VisitChildren(AstNodeVisitor* visitor) const;
 
   DECLARE_COMMON_NODE_FUNCTIONS(LetNode);
 
  private:
   GrowableArray<LocalVariable*> vars_;
   GrowableArray<AstNode*> initializers_;
-  AstNode* body_;
+  GrowableArray<AstNode*> nodes_;
 
   DISALLOW_COPY_AND_ASSIGN(LetNode);
 };
 
 
 class ArrayNode : public AstNode {
  public:
   ArrayNode(intptr_t token_pos, const AbstractType& type)
       : AstNode(token_pos),
         type_(type),
@@ skipping 1425 matching lines @@
   const LocalVariable& context_var_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(InlinedFinallyNode);
 };
 
 }  // namespace dart
 
 #undef DECLARE_COMMON_NODE_FUNCTIONS
 
 #endif  // VM_AST_H_