Add fasta parser cascade recovery

Change-Id: I1cf32604acf2124a9d61621fbb4cfb9343d98d33
Reviewed-on: https://dart-review.googlesource.com/28840
Reviewed-by: Johnni Winther <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Dan Rubel <[email protected]>

Author: Dan Rubel

pkg/analyzer/test/src/fasta/recovery/missing_code_test.dart

@@ -76,6 +76,18 @@ f() {
     testUserDefinableOperatorWithSuper('|');
   }
 
+  void test_cascade_missingRight() {
+    testRecovery('''
+f(x) {
+  x..
+}
+''', [ParserErrorCode.MISSING_IDENTIFIER, ParserErrorCode.EXPECTED_TOKEN], '''
+f(x) {
+  x.. _s_;
+}
+''');
+  }
+
   void test_classDeclaration_missingName() {
     testRecovery('''
 class {}

pkg/compiler/lib/src/diagnostics/messages.dart

@@ -2668,8 +2668,7 @@ main() {}
       MessageKind.EXPECTED_IDENTIFIER_NOT_RESERVED_WORD: const MessageTemplate(
           MessageKind.EXPECTED_IDENTIFIER_NOT_RESERVED_WORD,
           "'#{keyword}' is a reserved word and can't be used here.",
-          howToFix: "Try using a different name.",
-          examples: const ["do() {} main() {}"]),
+          howToFix: "Try using a different name."),
 
       MessageKind.NAMED_FUNCTION_EXPRESSION: const MessageTemplate(
           MessageKind.NAMED_FUNCTION_EXPRESSION,

pkg/front_end/lib/src/fasta/fasta_codes_generated.dart

@@ -1323,7 +1323,7 @@ const Template<Message Function(Token token)> templateExpectedIdentifier =
 const Code<Message Function(Token token)> codeExpectedIdentifier =
     const Code<Message Function(Token token)>(
         "ExpectedIdentifier", templateExpectedIdentifier,
-        analyzerCode: "MISSING_IDENTIFIER", dart2jsCode: "EXPECTED_IDENTIFIER");
+        analyzerCode: "MISSING_IDENTIFIER", dart2jsCode: "*fatal*");
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 Message _withArgumentsExpectedIdentifier(Token token) {

pkg/front_end/lib/src/fasta/parser/parser.dart

@@ -4459,11 +4459,9 @@ class Parser {
     listener.beginCascade(cascadeOperator);
     if (optional('[', token.next)) {
       token = parseArgumentOrIndexStar(token, null);
-    } else if (token.next.isIdentifier) {
+    } else {
       token = parseSend(token, IdentifierContext.expressionContinuation);
       listener.endBinaryExpression(cascadeOperator);
-    } else {
-      return reportUnexpectedToken(token.next);
     }
     Token next = token.next;
     Token mark;

pkg/front_end/messages.yaml

@@ -236,7 +236,7 @@ ExpectedHexDigit:
 ExpectedIdentifier:
   template: "Expected an identifier, but got '#lexeme'."
   analyzerCode: MISSING_IDENTIFIER
-  dart2jsCode: EXPECTED_IDENTIFIER
+  dart2jsCode: "*fatal*"
   script: "do() {} main() {}"
 
 EqualityCannotBeEqualityOperand: