more fasta event cleanup and testing

pkg/front_end/lib/src/fasta/parser/listener.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 fasta.parser.listener;
 
 import '../fasta_codes.dart' show Message;
 
 import '../../scanner/token.dart' show BeginToken, Token, TokenType;
 
@@ skipping 204 matching lines @@
   /// - Metadata
   /// - Modifiers
   /// - Type
   /// - Variable declarations (count times)
   ///
   /// Doesn't have a corresponding begin event, use [beginMember] instead.
   void endFields(int count, Token beginToken, Token endToken) {
     logEvent("Fields");
   }
 
+  /// Marks the start of a for statement which is ended by either
+  /// [endForStatement] or [endForIn].
   void beginForStatement(Token token) {}
 
   void endForStatement(Token forKeyword, Token leftSeparator,
       int updateExpressionCount, Token endToken) {
     logEvent("ForStatement");
   }
 
   void beginForStatementBody(Token token) {}
 
   void endForStatementBody(Token token) {
     logEvent("ForStatementBody");
   }
 
+  // One of the two possible corresponding end events for [beginForStatement].
   void endForIn(Token awaitToken, Token forToken, Token leftParenthesis,
       Token inKeyword, Token rightParenthesis, Token endToken) {
     logEvent("ForIn");
   }
 
   void beginForInExpression(Token token) {}
 
   void endForInExpression(Token token) {
     logEvent("ForInExpression");
   }
@@ skipping 439 matching lines @@
   }
 
   /// This event is added for convenience. Normally, one should use
   /// [endClassDeclaration], [endNamedMixinApplication], [endEnum],
   /// [endFunctionTypeAlias], [endLibraryName], [endImport], [endExport],
   /// [endPart], [endPartOf], [endTopLevelFields], or [endTopLevelMethod].
   void endTopLevelDeclaration(Token token) {
     logEvent("TopLevelDeclaration");
   }
 
+  /// Marks the beginning of a top level field or method declaration.
+  /// Doesn't have a corresponding end event.
+  /// See [endTopLevelFields] and [endTopLevelMethod].
   void beginTopLevelMember(Token token) {}
 
   /// Handle the end of a top level variable declaration.  Substructures:
   /// - Metadata
   /// - Modifiers
   /// - Type
   /// - Repeated [count] times:
   ///   - Variable name (identifier)
   ///   - Field initializer
-  /// Doesn't have a corresponding begin event, use [beginTopLevelMember]
-  /// instead.
+  /// Doesn't have a corresponding begin event.
+  /// Use [beginTopLevelMember] instead.
   void endTopLevelFields(int count, Token beginToken, Token endToken) {
     logEvent("TopLevelFields");
   }
 
   void beginTopLevelMethod(Token token, Token name) {}
 
   /// Handle the end of a top level method.  Substructures:
   /// - metadata
   /// - modifiers
   /// - return type
@@ skipping 271 matching lines @@
   void handleStringPart(Token token) {
     logEvent("StringPart");
   }
 
   void handleSuperExpression(Token token, IdentifierContext context) {
     logEvent("SuperExpression");
   }
 
   void beginSwitchCase(int labelCount, int expressionCount, Token firstToken) {}
 
-  void handleSwitchCase(
-      int labelCount,
-      int expressionCount,
-      Token defaultKeyword,
-      int statementCount,
-      Token firstToken,
-      Token endToken) {
+  void endSwitchCase(int labelCount, int expressionCount, Token defaultKeyword,
+      int statementCount, Token firstToken, Token endToken) {
     logEvent("SwitchCase");
   }
 
   void handleThisExpression(Token token, IdentifierContext context) {
     logEvent("ThisExpression");
   }
 
   void handleUnaryPostfixAssignmentExpression(Token token) {
     logEvent("UnaryPostfixAssignmentExpression");
   }
@@ skipping 94 matching lines @@
 
   final Message message;
 
   ParserError(this.beginOffset, this.endOffset, this.message);
 
   ParserError.fromTokens(Token begin, Token end, Message message)
       : this(begin.charOffset, end.charOffset + end.charCount, message);
 
   String toString() => "@${beginOffset}: ${message.message}\n${message.tip}";
 }