Use UnaryOperator and BinaryOperator in ConstantSystem.

pkg/compiler/lib/src/compile_time_constants.dart

 // 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.
 
 library dart2js.compile_time_constant_evaluator;
 
 import 'constant_system_dart.dart';
 import 'constants/constant_system.dart';
 import 'constants/expressions.dart';
 import 'constants/values.dart';
 import 'dart_types.dart';
 import 'dart2jslib.dart' show Compiler, CompilerTask, MessageKind, invariant;
 import 'elements/elements.dart';
 import 'elements/modelx.dart' show FunctionElementX;
 import 'resolution/resolution.dart';
+import 'resolution/operators.dart';
 import 'tree/tree.dart';
 import 'util/util.dart' show Link;
 import 'universe/universe.dart' show CallStructure;
 
 /// A [ConstantEnvironment] provides access for constants compiled for variable
 /// initializers.
 abstract class ConstantEnvironment {
   /// Returns the constant for the initializer of [element].
   ConstantExpression getConstantForVariable(VariableElement element);
 }
@@ skipping 522 matching lines @@
           && send.argumentCount() == 2) {
         AstConstant left = evaluate(send.argumentsNode.nodes.head);
         AstConstant right = evaluate(send.argumentsNode.nodes.tail.head);
         if (left == null || right == null) {
           return null;
         }
         ConstantValue result =
             constantSystem.identity.fold(left.value, right.value);
         if (result != null) {
           return new AstConstant(
-              context, send, new BinaryConstantExpression(result,
-                  left.expression, 'identical', right.expression));
+              context, send, new IdenticalConstantExpression(result,
+                  left.expression, right.expression));
         }
       }
       return signalNotCompileTimeConstant(send);
     } else if (send.isPrefix) {
       assert(send.isOperator);
       AstConstant receiverConstant = evaluate(send.receiver);
       if (receiverConstant == null) {
         return null;
       }
-      Operator op = send.selector;
-      UnaryOperation operation = constantSystem.lookupUnary(op.source);
+      Operator node = send.selector;
+      UnaryOperator operator = UnaryOperator.parse(node.source);
+      UnaryOperation operation = constantSystem.lookupUnary(operator);
       if (operation == null) {
-        compiler.internalError(op, "Unexpected operator.");
+        compiler.internalError(send.selector, "Unexpected operator.");
       }
       ConstantValue folded = operation.fold(receiverConstant.value);
       if (folded == null) {
         return signalNotCompileTimeConstant(send);
       }
       return new AstConstant(
           context, send, new UnaryConstantExpression(folded,
-              op.source, receiverConstant.expression));
+              operator, receiverConstant.expression));
     } else if (send.isOperator && !send.isPostfix) {
       assert(send.argumentCount() == 1);
       AstConstant left = evaluate(send.receiver);
       AstConstant right = evaluate(send.argumentsNode.nodes.head);
       if (left == null || right == null) {
         return null;
       }
       ConstantValue leftValue = left.value;
       ConstantValue rightValue = right.value;
-      Operator op = send.selector.asOperator();
+      Operator node = send.selector.asOperator();
+      BinaryOperator operator = BinaryOperator.parse(node.source);
       ConstantValue folded = null;
-      switch (op.source) {
-        case "==":
+      switch (operator.kind) {
+        case BinaryOperatorKind.EQ:
           if (leftValue.isPrimitive && rightValue.isPrimitive) {
             folded = constantSystem.equal.fold(leftValue, rightValue);
           }
           break;
-        case "!=":
+        case BinaryOperatorKind.NOT_EQ:
           if (leftValue.isPrimitive && rightValue.isPrimitive) {
             BoolConstantValue areEquals =
                 constantSystem.equal.fold(leftValue, rightValue);
             if (areEquals == null) {
               folded = null;
             } else {
               folded = areEquals.negate();
             }
           }
           break;
         default:
-          BinaryOperation operation = constantSystem.lookupBinary(op.source);
+          BinaryOperation operation = constantSystem.lookupBinary(operator);
           if (operation != null) {
             folded = operation.fold(leftValue, rightValue);
           }
       }
       if (folded == null) {
         return signalNotCompileTimeConstant(send);
       }
       return new AstConstant(
           context, send, new BinaryConstantExpression(folded,
-              left.expression, op.source, right.expression));
+              left.expression, operator, right.expression));
     }
     return signalNotCompileTimeConstant(send);
   }
 
   AstConstant visitConditional(Conditional node) {
     AstConstant condition = evaluate(node.condition);
     if (condition == null) {
       return null;
     } else if (!condition.value.isBool) {
       DartType conditionType = condition.value.getType(compiler.coreTypes);
@@ skipping 501 matching lines @@
   ConstantValue get value => expression.value;
 
   String toString() => expression.toString();
 }
 
 /// A synthetic constant used to recover from errors.
 class ErroneousAstConstant extends AstConstant {
   ErroneousAstConstant(Element element, Node node)
       : super(element, node, new ErroneousConstantExpression());
 }