Parse parenthesized expressions.

dart/frog/leg/scanner/parser.dart

 // Copyright (c) 2011, 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.
 
 /**
  * An event generating parser of Dart programs. This parser expects
  * all tokens in a linked list.
  */
 class PartialParser<L extends Listener> {
   final L listener;
@@ skipping 616 matching lines @@
         final value = token.stringValue;
         if ((value === 'true') || (value === 'false')) {
           return parseLiteralBool(token);
         } else if (value === 'null') {
           return parseLiteralNull(token);
         } else {
           listener.unexpected(token);
           throw 'not yet implemented';
         }
       }
+    } else if (kind === LPAREN_TOKEN) {
+      return parseParenthesizedExpression(token);
     } else {
       listener.unexpected(token);
       throw 'not yet implemented';
     }
   }
 
+  Token parseParenthesizedExpression(Token token) {
+    BeginGroupToken begin = token;
+    token = expect('(', token);
+    token = parseExpression(token);
+    assert(begin.endGroup === token);
+    listener.handleParenthesizedExpression(begin);
+    return expect(')', token);
+  }
+
   Token parseLiteralInt(Token token) {
     listener.handleLiteralInt(token);
     return token.next;
   }
 
   Token parseLiteralDouble(Token token) {
     listener.handleLiteralDouble(token);
     return token.next;
   }
 
@@ skipping 78 matching lines @@
       return token.next;
     } else {
       return parseType(token);
     }
   }
 
   Token parseIfStatement(Token token) {
     Token ifToken = token;
     listener.beginIfStatement(ifToken);
     token = expect('if', token);
-    expect('(', token);
-    token = parseArguments(token);
+    token = parseParenthesizedExpression(token);
     token = parseStatement(token);
     Token elseToken = null;
     if (optional('else', token)) {
       elseToken = token;
       token = parseStatement(token.next);
     }
     listener.endIfStatement(ifToken, elseToken);
     return token;
   }
 
   Token parseForStatement(Token token) {
     // TODO(ahe): Support for-in.
     Token forToken = token;
     listener.beginForStatement(forToken);
     token = expect('for', token);
     token = expect('(', token);
     token = parseVariablesDeclaration(token); // TODO(ahe): Support other forms.
     token = parseExpressionStatement(token);
     token = parseExpression(token); // TODO(ahe): Support expression list here.
     token = expect(')', token);
     token = parseStatement(token);
     listener.endForStatement(forToken, token);
     return token;
   }
 
   Token parseWhileStatement(Token token) {
     Token whileToken = token;
     listener.beginWhileStatement(whileToken);
     token = expect('while', token);
-    token = expect('(', token);
-    token = parseExpression(token);
-    token = expect(')', token);
+    token = parseParenthesizedExpression(token);
     token = parseStatement(token);
     listener.endWhileStatement(whileToken, token);
     return token;
   }
 
   Token parseDoWhileStatement(Token token) {
     Token doToken = token;
     listener.beginDoWhileStatement(doToken);
     token = expect('do', token);
     token = parseStatement(token);
     Token whileToken = token;
     token = expect('while', token);
-    token = expect('(', token);
-    token = parseExpression(token);
-    token = expect(')', token);
+    token = parseParenthesizedExpression(token);
     listener.endDoWhileStatement(doToken, whileToken, token);
     return expectSemicolon(token);
   }
 
   Token parseBlock(Token token) {
     Token begin = token;
     listener.beginBlock(begin);
     int statementCount = 0;
     token = expect('{', token);
     while (!optional('}', token)) {
@@ skipping 11 matching lines @@
     if (optional(';', token)) {
       listener.endRethrowStatement(throwToken, token);
       return token.next;
     } else {
       token = parseExpression(token);
       listener.endThrowStatement(throwToken, token);
       return expectSemicolon(token);
     }
   }
 }