Better error recovery.

dart/frog/leg/scanner/parser.dart

Index: dart/frog/leg/scanner/parser.dart
diff --git a/dart/frog/leg/scanner/parser.dart b/dart/frog/leg/scanner/parser.dart
index 009867fe19cdc7707f46e0e749d90c94f76c93a0..a9bf4cb27ed9bd756e876d1131930a162785b4f5 100644
--- a/dart/frog/leg/scanner/parser.dart
+++ b/dart/frog/leg/scanner/parser.dart
@@ -188,7 +188,7 @@ class Parser {
 
   Token skipBlock(Token token) {
     if (!optional('{', token)) {
-      return listener.expectedBlock(token);
+      return listener.unexpected(token);
     }
     BeginGroupToken beginGroupToken = token;
     assert(beginGroupToken.endGroup === null ||
@@ -369,7 +369,7 @@ class Parser {
         if (token.kind === EOF_TOKEN) {
           // TODO(ahe): This is a hack. It would be better to tell the
           // listener more explicitly that it must pop an identifier.

[ngeoffray, 2012/01/10 07:49:45]

Is that still a hack?

[ahe, 2012/01/10 08:02:28]

Yes. Something is wrong here, but we don't know what the user intended. Calling
endTopLevelFields keeps the node stack in the listener well balanced, but we
should explicitly tell the listener that this isn't a field.

[ngeoffray, 2012/01/10 08:07:09]

So should you do the same line 555?

[ahe, 2012/01/10 08:32:33]

Done.

-          listener.endTopLevelFields(0, start, token);
+          listener.endTopLevelFields(1, start, token);
           return token;
         }
       }
@@ -479,7 +479,7 @@ class Parser {
   Token peekAfterType(Token token) {
     // TODO(ahe): Also handle var?
     if ('void' !== token.stringValue && !isIdentifier(token)) {
-      listener.expectedIdentifier(token);
+      listener.unexpected(token);
     }
     // We are looking at "identifier ...".
     Token peek = token.next;
@@ -507,7 +507,9 @@ class Parser {
     Token begin = token;
     listener.beginClassBody(token);
     if (!optional('{', token)) {
-      return listener.expectedBlock(token);
+      token = listener.unexpected(token);
+      listener.endClassBody(0, begin, null);
+      return token;
     }
     token = token.next;
     int count = 0;
@@ -549,6 +551,10 @@ class Parser {
         break;
       } else {
         token = listener.unexpected(token);
+        if (token.kind === EOF_TOKEN) {
+          listener.endFields(1, start, token);
+          return token;
+        }
       }
     }
     if (isField) {
@@ -995,7 +1001,10 @@ class Parser {
     BeginGroupToken begin = token;
     token = expect('(', token);
     token = parseExpression(token);
-    assert(begin.endGroup === token);
+    if (begin.endGroup !== token) {
+      listener.unexpected(token);
+      token = begin.endGroup;
+    }
     listener.handleParenthesizedExpression(begin);
     return expect(')', token);
   }
@@ -1110,7 +1119,12 @@ class Parser {
       named = true;
       token = parseIdentifier(token.next);
     }
-    token = parseArguments(token);
+    if (optional('(', token)) {
+      token = parseArguments(token);
+    } else {
+      listener.handleNoArguments(token);
+      token = listener.unexpected(token);
+    }
     listener.handleNewExpression(newKeyword, named);
     return token;
   }