Add new style of string interpolation optimization: new nodes, working constant folding.

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 42 matching lines @@
   V(LoadStaticField)                                                           \
   V(StoreStaticField)                                                          \
   V(LoadIndexed)                                                               \
   V(StoreIndexed)                                                              \
   V(Sequence)                                                                  \
   V(Let)                                                                       \
   V(CatchClause)                                                               \
   V(TryCatch)                                                                  \
   V(Throw)                                                                     \
   V(InlinedFinally)                                                            \
+  V(StringInterpolate)                                                         \
 
 
 #define FORWARD_DECLARATION(BaseName) class BaseName##Node;
 FOR_EACH_NODE(FORWARD_DECLARATION)
 #undef FORWARD_DECLARATION
 
 
 // Abstract class to implement an AST node visitor. An example is AstPrinter.
 class AstNodeVisitor : public ValueObject {
  public:
@@ skipping 226 matching lines @@
     ASSERT(type_.IsFinalized());
     // Type may be uninstantiated when creating a generic list literal.
     ASSERT((type_.arguments() == AbstractTypeArguments::null()) ||
            ((AbstractTypeArguments::Handle(type_.arguments()).Length() == 1)));
   }
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(ArrayNode);
 };
 
 
+class StringInterpolateNode : public AstNode {
+ public:
+  StringInterpolateNode(intptr_t token_pos, ArrayNode* value)
+      : AstNode(token_pos), value_(value) { }
+
+  virtual void VisitChildren(AstNodeVisitor* visitor) const {
+    value_->Visit(visitor);
+  }
+
+  ArrayNode* value() const { return value_; }
+
+  DECLARE_COMMON_NODE_FUNCTIONS(StringInterpolateNode);
+
+ private:
+  ArrayNode* value_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(StringInterpolateNode);
+};
+
+
 class LiteralNode : public AstNode {
  public:
   LiteralNode(intptr_t token_pos, const Instance& literal)
       : AstNode(token_pos), literal_(literal) {
     ASSERT(literal_.IsNotTemporaryScopedHandle());
     ASSERT(literal_.IsSmi() || literal_.IsOld());
 #if defined(DEBUG)
     if (literal_.IsString()) {
       ASSERT(String::Cast(literal_).IsSymbol());
     }
@@ skipping 1438 matching lines @@
   const intptr_t try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(InlinedFinallyNode);
 };
 
 }  // namespace dart
 
 #undef DECLARE_COMMON_NODE_FUNCTIONS
 
 #endif  // VM_AST_H_