Move parser helper classes to own files and clean them up.

pkg/front_end/lib/src/fasta/source/outline_builder.dart

 // Copyright (c) 2016, 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.outline_builder;
 
 import 'package:kernel/ast.dart' show ProcedureKind;
 
 import '../../scanner/token.dart' show Token;
 
@@ skipping 13 matching lines @@
 
 import '../modifier.dart' show abstractMask, externalMask, Modifier;
 
 import '../operator.dart'
     show
         Operator,
         operatorFromString,
         operatorToString,
         operatorRequiredArgumentCount;
 
-import '../parser/identifier_context.dart' show IdentifierContext;
-
 import '../parser/native_support.dart'
     show extractNativeMethodName, removeNativeClause, skipNativeClause;
 
-import '../parser/parser.dart' show FormalParameterType, MemberKind, optional;
+import '../parser.dart'
+    show FormalParameterKind, IdentifierContext, MemberKind, optional;
 
 import '../problems.dart' show unhandled, unimplemented;
 
 import '../quote.dart' show unescapeString;
 
 import '../util/link.dart' show Link;
 
 import 'source_library_builder.dart' show SourceLibraryBuilder;
 
 import 'unhandled_listener.dart' show NullValue, Unhandled, UnhandledListener;
@@ skipping 438 matching lines @@
   }
 
   @override
   void handleVoidKeyword(Token token) {
     debugEvent("VoidKeyword");
     push(library.addVoidType(token.charOffset));
   }
 
   @override
   void endFormalParameter(Token thisKeyword, Token nameToken,
-      FormalParameterType kind, MemberKind memberKind) {
+      FormalParameterKind kind, MemberKind memberKind) {
     debugEvent("FormalParameter");
     int charOffset = pop();
     String name = pop();
     TypeBuilder type = pop();
     int modifiers = Modifier.validate(pop());
     List<MetadataBuilder> metadata = pop();
     push(library.addFormalParameter(
         metadata, modifiers, type, name, thisKeyword != null, charOffset));
   }
 
   @override
   void handleValuedFormalParameter(Token equals, Token token) {
     debugEvent("ValuedFormalParameter");
     // Ignored for now.
   }
 
   @override
   void handleFormalParameterWithoutValue(Token token) {
     debugEvent("FormalParameterWithoutValue");
     // Ignored for now.
   }
 
   @override
   void endOptionalFormalParameters(
       int count, Token beginToken, Token endToken) {
     debugEvent("OptionalFormalParameters");
-    FormalParameterType kind = optional("{", beginToken)
-        ? FormalParameterType.NAMED
-        : FormalParameterType.POSITIONAL;
+    FormalParameterKind kind = optional("{", beginToken)
+        ? FormalParameterKind.optionalNamed
+        : FormalParameterKind.optionalPositional;
     // When recovering from an empty list of optional arguments, count may be
     // 0. It might be simpler if the parser didn't call this method in that
     // case, however, then [beginOptionalFormalParameters] wouldn't always be
     // matched by this method.
     List parameters = popList(count) ?? [];
     for (FormalParameterBuilder parameter in parameters) {
       parameter.kind = kind;
     }
     push(parameters);
   }
@@ skipping 355 matching lines @@
   Link<Token> handleMemberName(Link<Token> identifiers) {
     if (!enableNative || identifiers.isEmpty) return identifiers;
     return removeNativeClause(identifiers, stringExpectedAfterNative);
   }
 
   @override
   void debugEvent(String name) {
     // printEvent(name);
   }
 }