Support serialization of the compiler backbone.

pkg/compiler/lib/src/constants/expressions.dart

 // Copyright (c) 2014, 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.
 
 library dart2js.constants.expressions;
 
 import '../constants/constant_system.dart';
 import '../core_types.dart';
 import '../dart2jslib.dart' show assertDebugMode, Compiler;
 import '../dart_types.dart';
@@ skipping 89 matching lines @@
 
   /// Computes the type of the instance created in a const constructor
   /// invocation with type [newType].
   InterfaceType computeInstanceType(InterfaceType newType);
 
   /// Computes the constant expressions of the fields of the created instance
   /// in a const constructor invocation with [arguments].
   Map<FieldElement, ConstantExpression> computeInstanceFields(
       List<ConstantExpression> arguments,
       CallStructure callStructure);
+
+  accept(ConstantConstructorVisitor visitor, arg);
+}
+
+abstract class ConstantConstructorVisitor<R, A> {
+  const ConstantConstructorVisitor();
+
+  R visit(ConstantConstructor constantConstructor, A context) {
+    return constantConstructor.accept(this, context);
+  }
+
+  R visitGenerative(GenerativeConstantConstructor constructor, A arg);
+  R visitRedirectingGenerative(
+      RedirectingGenerativeConstantConstructor constructor, A arg);
+  R visitRedirectingFactory(
+      RedirectingFactoryConstantConstructor constructor, A arg);
 }
 
 /// A generative constant constructor.
 class GenerativeConstantConstructor implements ConstantConstructor{
   final InterfaceType type;
   final Map<dynamic/*int|String*/, ConstantExpression> defaultValues;
   final Map<FieldElement, ConstantExpression> fieldMap;
   final ConstructedConstantExpression superConstructorInvocation;
 
   GenerativeConstantConstructor(
@@ skipping 14 matching lines @@
     NormalizedArguments args = new NormalizedArguments(
         defaultValues, callStructure, arguments);
     Map<FieldElement, ConstantExpression> appliedFieldMap =
         applyFields(args, superConstructorInvocation);
     fieldMap.forEach((FieldElement field, ConstantExpression constant) {
      appliedFieldMap[field] = constant.apply(args);
     });
     return appliedFieldMap;
   }
 
+  accept(ConstantConstructorVisitor visitor, arg) {
+    return visitor.visitGenerative(this, arg);
+  }
+
   String toString() {
     StringBuffer sb = new StringBuffer();
     sb.write("{'type': $type");
     defaultValues.forEach((key, ConstantExpression expression) {
       sb.write(",\n 'default:${key}': ${expression.getText()}");
     });
     fieldMap.forEach((FieldElement field, ConstantExpression expression) {
       sb.write(",\n 'field:${field}': ${expression.getText()}");
     });
     if (superConstructorInvocation != null) {
@@ skipping 44 matching lines @@
       List<ConstantExpression> arguments,
       CallStructure callStructure) {
     NormalizedArguments args =
         new NormalizedArguments(defaultValues, callStructure, arguments);
     Map<FieldElement, ConstantExpression> appliedFieldMap =
         GenerativeConstantConstructor.applyFields(
             args, thisConstructorInvocation);
     return appliedFieldMap;
   }
 
+  accept(ConstantConstructorVisitor visitor, arg) {
+    return visitor.visitRedirectingGenerative(this, arg);
+  }
+
   String toString() {
     StringBuffer sb = new StringBuffer();
     sb.write("{'type': ${thisConstructorInvocation.type}");
     defaultValues.forEach((key, ConstantExpression expression) {
       sb.write(",\n 'default:${key}': ${expression.getText()}");
     });
     sb.write(",\n 'constructor': ${thisConstructorInvocation.getText()}");
     sb.write("}");
     return sb.toString();
   }
@@ skipping 15 matching lines @@
   }
 
   Map<FieldElement, ConstantExpression> computeInstanceFields(
       List<ConstantExpression> arguments,
       CallStructure callStructure) {
     ConstantConstructor constantConstructor =
         targetConstructorInvocation.target.constantConstructor;
     return constantConstructor.computeInstanceFields(arguments, callStructure);
   }
 
+  accept(ConstantConstructorVisitor visitor, arg) {
+    return visitor.visitRedirectingFactory(this, arg);
+  }
+
   String toString() {
     StringBuffer sb = new StringBuffer();
     sb.write("{");
     sb.write("'constructor': ${targetConstructorInvocation.getText()}");
     sb.write("}");
     return sb.toString();
   }
 }
 
 /// An expression that is a compile-time constant.
@@ skipping 1542 matching lines @@
     visit(exp.name);
     if (exp.defaultValue != null) {
       sb.write(', defaultValue: ');
       visit(exp.defaultValue);
     }
     sb.write(')');
   }
 
   String toString() => sb.toString();
 }