Remove AbstractVisitor.

dart/lib/compiler/implementation/tree/nodes.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.
 
 abstract class Visitor<R> {
-  R visitBlock(Block node);
-  R visitBreakStatement(BreakStatement node);
-  R visitCascade(Cascade node);
-  R visitCascadeReceiver(CascadeReceiver node);
-  R visitCaseMatch(CaseMatch node);
-  R visitCatchBlock(CatchBlock node);
-  R visitClassNode(ClassNode node);
-  R visitConditional(Conditional node);
-  R visitContinueStatement(ContinueStatement node);
-  R visitDoWhile(DoWhile node);
-  R visitEmptyStatement(EmptyStatement node);
-  R visitExpressionStatement(ExpressionStatement node);
-  R visitFor(For node);
-  R visitForIn(ForIn node);
-  R visitFunctionDeclaration(FunctionDeclaration node);
-  R visitFunctionExpression(FunctionExpression node);
-  R visitIdentifier(Identifier node);
-  R visitIf(If node);
-  R visitLabel(Label node);
-  R visitLabeledStatement(LabeledStatement node);
-  R visitLiteralBool(LiteralBool node);
-  R visitLiteralDouble(LiteralDouble node);
-  R visitLiteralInt(LiteralInt node);
-  R visitLiteralList(LiteralList node);
-  R visitLiteralMap(LiteralMap node);
-  R visitLiteralMapEntry(LiteralMapEntry node);
-  R visitLiteralNull(LiteralNull node);
-  R visitLiteralString(LiteralString node);
-  R visitModifiers(Modifiers node);
-  R visitNamedArgument(NamedArgument node);
-  R visitNewExpression(NewExpression node);
-  R visitNodeList(NodeList node);
-  R visitOperator(Operator node);
-  R visitParenthesizedExpression(ParenthesizedExpression node);
-  R visitReturn(Return node);
-  R visitScriptTag(ScriptTag node);
-  R visitSend(Send node);
-  R visitSendSet(SendSet node);
-  R visitStringInterpolation(StringInterpolation node);
-  R visitStringInterpolationPart(StringInterpolationPart node);
-  R visitStringJuxtaposition(StringJuxtaposition node);
-  R visitSwitchCase(SwitchCase node);
-  R visitSwitchStatement(SwitchStatement node);
-  R visitThrow(Throw node);
-  R visitTryStatement(TryStatement node);
-  R visitTypeAnnotation(TypeAnnotation node);
-  R visitTypedef(Typedef node);
-  R visitTypeVariable(TypeVariable node);
-  R visitVariableDefinitions(VariableDefinitions node);
-  R visitWhile(While node);
+  const Visitor();
+
+  abstract R visitNode(Node node);
+
+  R visitBlock(Block node) => visitStatement(node);
+  R visitBreakStatement(BreakStatement node) => visitGotoStatement(node);
+  R visitCascade(Cascade node) => visitExpression(node);
+  R visitCascadeReceiver(CascadeReceiver node) => visitExpression(node);
+  R visitCaseMatch(CaseMatch node) => visitNode(node);
+  R visitCatchBlock(CatchBlock node) => visitNode(node);
+  R visitClassNode(ClassNode node) => visitNode(node);
+  R visitConditional(Conditional node) => visitExpression(node);
+  R visitContinueStatement(ContinueStatement node) => visitGotoStatement(node);
+  R visitDoWhile(DoWhile node) => visitLoop(node);
+  R visitEmptyStatement(EmptyStatement node) => visitStatement(node);
+  R visitExpression(Expression node) => visitNode(node);
+  R visitExpressionStatement(ExpressionStatement node) => visitStatement(node);
+  R visitFor(For node) => visitLoop(node);
+  R visitForIn(ForIn node) => visitLoop(node);
+  R visitFunctionDeclaration(FunctionDeclaration node) => visitStatement(node);
+  R visitFunctionExpression(FunctionExpression node) => visitExpression(node);
+  R visitGotoStatement(GotoStatement node) => visitStatement(node);
+  R visitIdentifier(Identifier node) => visitExpression(node);
+  R visitIf(If node) => visitStatement(node);
+  R visitLabel(Label node) => visitNode(node);
+  R visitLabeledStatement(LabeledStatement node) => visitStatement(node);
+  R visitLiteral(Literal node) => visitExpression(node);
+  R visitLiteralBool(LiteralBool node) => visitLiteral(node);
+  R visitLiteralDouble(LiteralDouble node) => visitLiteral(node);
+  R visitLiteralInt(LiteralInt node) => visitLiteral(node);
+  R visitLiteralList(LiteralList node) => visitExpression(node);
+  R visitLiteralMap(LiteralMap node) => visitExpression(node);
+  R visitLiteralMapEntry(LiteralMapEntry node) => visitNode(node);
+  R visitLiteralNull(LiteralNull node) => visitLiteral(node);
+  R visitLiteralString(LiteralString node) => visitStringNode(node);
+  R visitStringJuxtaposition(StringJuxtaposition node) => visitStringNode(node);
+  R visitLoop(Loop node) => visitStatement(node);
+  R visitModifiers(Modifiers node) => visitNode(node);
+  R visitNamedArgument(NamedArgument node) => visitExpression(node);
+  R visitNewExpression(NewExpression node) => visitExpression(node);
+  R visitNodeList(NodeList node) => visitNode(node);
+  R visitOperator(Operator node) => visitIdentifier(node);
+  R visitParenthesizedExpression(ParenthesizedExpression node) {
+    return visitExpression(node);
+  }
+  R visitPostfix(Postfix node) => visitNodeList(node);
+  R visitPrefix(Prefix node) => visitNodeList(node);
+  R visitReturn(Return node) => visitStatement(node);
+  R visitScriptTag(ScriptTag node) => visitNode(node);
+  R visitSend(Send node) => visitExpression(node);
+  R visitSendSet(SendSet node) => visitSend(node);
+  R visitStatement(Statement node) => visitNode(node);
+  R visitStringNode(StringNode node) => visitExpression(node);
+  R visitStringInterpolation(StringInterpolation node) => visitStringNode(node);
+  R visitStringInterpolationPart(StringInterpolationPart node) {
+    return visitNode(node);
+  }
+  R visitSwitchCase(SwitchCase node) => visitNode(node);
+  R visitSwitchStatement(SwitchStatement node) => visitStatement(node);
+  R visitThrow(Throw node) => visitStatement(node);
+  R visitTryStatement(TryStatement node) => visitStatement(node);
+  R visitTypeAnnotation(TypeAnnotation node) => visitNode(node);
+  R visitTypedef(Typedef node) => visitNode(node);
+  R visitTypeVariable(TypeVariable node) => visitNode(node);
+  R visitVariableDefinitions(VariableDefinitions node) => visitStatement(node);
+  R visitWhile(While node) => visitLoop(node);
 }
 
 Token firstBeginToken(Node first, Node second) {
   Token token = null;
   if (first !== null) {
     token = first.getBeginToken();
   }
   if (token === null && second !== null) {
     // [token] might be null even when [first] is not, e.g. for empty Modifiers.
     token = second.getBeginToken();
@@ skipping 1799 matching lines @@
     return (node.receiver === null &&
             node.selector.asIdentifier() !== null &&
             node.selector.asIdentifier().isThis()) ||
            (node.receiver !== null &&
             node.receiver.asIdentifier() !== null &&
             node.receiver.asIdentifier().isThis() &&
             node.selector.asIdentifier() !== null);
   }
 }
 
-class GetDartStringVisitor extends AbstractVisitor<DartString> {
+class GetDartStringVisitor extends Visitor<DartString> {
   const GetDartStringVisitor();
   DartString visitNode(Node node) => null;
   DartString visitStringJuxtaposition(StringJuxtaposition node)
       => node.dartString;
   DartString visitLiteralString(LiteralString node) => node.dartString;
 }
 
-class IsInterpolationVisitor extends AbstractVisitor<bool> {
+class IsInterpolationVisitor extends Visitor<bool> {
   const IsInterpolationVisitor();
   bool visitNode(Node node) => false;
   bool visitStringInterpolation(StringInterpolation node) => true;
   bool visitStringJuxtaposition(StringJuxtaposition node)
       => node.isInterpolation;
 }
 
 /**
  * If the given node is a send set, it visits its initializer (first
  * argument).
  *
  * TODO(ahe): This method is controversial, the team needs to discuss
  * if top-level methods are acceptable and what naming conventions to
  * use.
  */
 initializerDo(Node node, f(Node node)) {
   SendSet send = node.asSendSet();
   if (send !== null) return f(send.arguments.head);
 }