Add support for the new function-type syntax.

pkg/front_end/lib/src/fasta/analyzer/ast_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.analyzer.ast_builder;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/dart/ast/ast_factory.dart' show AstFactory;
 import 'package:analyzer/dart/ast/standard_ast_factory.dart' as standard;
 import 'package:analyzer/dart/ast/token.dart' as analyzer show Token;
@@ skipping 421 matching lines @@
   void endLiteralSymbol(Token hashToken, int identifierCount) {
     debugEvent("LiteralSymbol");
     List<analyzer.Token> components = new List<analyzer.Token>(identifierCount);
     for (int i = identifierCount - 1; i >= 0; i--) {
       SimpleIdentifier identifier = pop();
       components[i] = identifier.token;
     }
     push(ast.symbolLiteral(toAnalyzerToken(hashToken), components));
   }
 
-  void endType(Token beginToken, Token endToken) {
+  void handleType(Token beginToken, Token endToken) {
     debugEvent("Type");
     TypeArgumentList arguments = pop();
     Identifier name = pop();
     // TODO(paulberry,ahe): what if the type doesn't resolve to a class
     // element?
     KernelClassElement cls = name.staticElement;
     if (cls == null) {
       // TODO(paulberry): This is a kludge.  Ideally we should already have
       // set the static element at the time that handleIdentifier was called.
       Builder builder = scope.lookup(name.name, beginToken.charOffset, uri);
@@ skipping 637 matching lines @@
     debugEvent("Member");
   }
 
   @override
   void handleVoidKeyword(Token token) {
     debugEvent("VoidKeyword");
     // TODO(paulberry): is this sufficient, or do we need to hook the "void"
     // keyword up to an element?
     handleIdentifier(token);
     handleNoTypeArguments(token);
-    endType(token, token);
+    handleType(token, token);
   }
 
   @override
-  void endFunctionTypeAlias(Token typedefKeyword, Token endToken) {
+  void endFunctionTypeAlias(
+      Token typedefKeyword, Token equals, Token endToken) {
     debugEvent("FunctionTypeAlias");
-    FormalParameterList parameters = pop();
-    TypeParameterList typeParameters = pop();
-    SimpleIdentifier name = pop();
-    TypeAnnotation returnType = pop();
-    List<Annotation> metadata = pop();
-    // TODO(paulberry): capture doc comments.  See dartbug.com/28851.
-    Comment comment = null;
-    push(ast.functionTypeAlias(
-        comment,
-        metadata,
-        toAnalyzerToken(typedefKeyword),
-        returnType,
-        name,
-        typeParameters,
-        parameters,
-        toAnalyzerToken(endToken)));
+    if (equals == null) {
+      FormalParameterList parameters = pop();
+      TypeParameterList typeParameters = pop();
+      SimpleIdentifier name = pop();
+      TypeAnnotation returnType = pop();
+      List<Annotation> metadata = pop();
+      // TODO(paulberry): capture doc comments.  See dartbug.com/28851.
+      Comment comment = null;
+      push(ast.functionTypeAlias(
+          comment,
+          metadata,
+          toAnalyzerToken(typedefKeyword),
+          returnType,
+          name,
+          typeParameters,
+          parameters,
+          toAnalyzerToken(endToken)));
+    } else {
+      Node type = pop();

[Paul Berry, 2017/02/22 18:47:25]

Shouldn't the type of `type` be TypeAnnotation?

[floitsch, 2017/02/22 19:21:39]

Maybe. I wasn't sure.
Changed to TypeAnnotation.

This only happens if it can't parse a function-type, and I don't know how the
error-recovery is implemented, and what type is produced if things go wrong. I'm
not even sure they can go wrong...

+      TypeParameterList templateParameters = pop();
+      SimpleIdentifier name = pop();
+      List<Annotation> metadata = pop();
+

[Paul Berry, 2017/02/22 18:47:25]

Duplicate lines 1113-1114 here.

[floitsch, 2017/02/22 19:21:39]

Done.

+      if (type is! GenericFunctionType) {
+        // TODO(brianwilkerson) Generate an error and recover (better than
+        // this).
+        push(ast.genericTypeAlias(
+            commentAndMetadata.comment,

[Paul Berry, 2017/02/22 18:47:26]

Change to "comment"

[floitsch, 2017/02/22 19:21:40]

Acknowledged.

+            commentAndMetadata.metadata,

[Paul Berry, 2017/02/22 18:47:25]

Change to "metadata"

[floitsch, 2017/02/22 19:21:39]

Acknowledged.

+            keyword,

[Paul Berry, 2017/02/22 18:47:26]

Change to "toAnalyzerToken(typedefKeyword)"

[floitsch, 2017/02/22 19:21:39]

Acknowledged.

+            name,
+            typeParameters,
+            equals,

[Paul Berry, 2017/02/22 18:47:26]

Change to "toAnalyzerToken(equals)"

[floitsch, 2017/02/22 19:21:39]

Acknowledged.

+            null,
+            semicolon));

[Paul Berry, 2017/02/22 18:47:26]

Change to "toAnalyzerToken(endToken)"

[floitsch, 2017/02/22 19:21:39]

Acknowledged.

+      } else {
+        FunctionTypeAnnotation functionType = type;

[Paul Berry, 2017/02/22 18:47:26]

I'm confused by this.  Since the if-test on line 1130 is "if type is!
GenericFunctionType)", the type of `type` is now known to be
GenericFunctionType.  I don't know what FunctionTypeAnnotation is.

Suggestion: rework the if-test to the form:

if (type is Foo) {
  ...
} else if (type is Bar) {
  ...
} else {
  internalError('Unexpected kind of type: ${type.runtimeType}');
}

[floitsch, 2017/02/22 19:21:40]

Changed the whole thing.

+        push(ast.genericTypeAlias(
+            commentAndMetadata.comment,

[Paul Berry, 2017/02/22 18:47:25]

Change to "comment"

[floitsch, 2017/02/22 19:21:39]

Done.

+            commentAndMetadata.metadata,

[Paul Berry, 2017/02/22 18:47:25]

Change to "metadata"

[floitsch, 2017/02/22 19:21:39]

Done.

+            keyword,

[Paul Berry, 2017/02/22 18:47:25]

Change to "toAnalyzerToken(typedefKeyword)"

[floitsch, 2017/02/22 19:21:39]

Done.

+            name,
+            typeParameters,
+            equals,

[Paul Berry, 2017/02/22 18:47:26]

Change to "toAnalyzerToken(equals)"

[floitsch, 2017/02/22 19:21:39]

Done.

+            functionType,
+            semicolon));

[Paul Berry, 2017/02/22 18:47:25]

Change to "toAnalyzerToken(endToken)"

[floitsch, 2017/02/22 19:21:39]

Done.

+      }
+    }
   }
 
   /**
    * Pop the modifiers list, if the list is empty return `null`, if the list
    * has one item return it; otherwise return `null`.
    */
   Token _popOptionalSingleModifier() {
     List<Token> modifiers = pop();
     if (modifiers.length == 0) {
       return null;
@@ skipping 31 matching lines @@
 /// [ClassDeclaration] or [ClassTypeAlias] object.
 class _MixinApplication {
   final TypeName supertype;
 
   final Token withKeyword;
 
   final List<TypeName> mixinTypes;
 
   _MixinApplication(this.supertype, this.withKeyword, this.mixinTypes);
 }