Add support for the new function-type syntax.

pkg/compiler/lib/src/resolution/signatures.dart

 // Copyright (c) 2014, 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 dart2js.resolution.signatures;
 
 import '../common.dart';
 import '../common/resolution.dart';
 import '../dart_types.dart';
 import '../elements/elements.dart';
@@ skipping 76 matching lines @@
       reporter.reportErrorMessage(node, MessageKind.FORMAL_DECLARED_CONST);
     }
     if (node.modifiers.isStatic) {
       reporter.reportErrorMessage(node, MessageKind.FORMAL_DECLARED_STATIC);
     }
 
     if (currentDefinitions != null) {
       reporter.internalError(node, 'function type parameters not supported');
     }
     currentDefinitions = node;
-    FormalElementX element = definition.accept(this);
+    FormalElementX element = definition == new NoIdentifier()

[Siggi Cherem (dart-lang), 2016/12/29 22:46:57]

nit: this is more of a readability nit, than anything else. I understand that
the `new NoIdentifier` is returning a singleton instance, but seeing the `new`
here does make you think twice about what this code is doing.

Other options:
  - definition == NoIdentifier.singleton
  - definition.isNoIdentifier // or .isIdentifierPlaceholder
  - definition == null ?

[floitsch, 2016/12/30 14:55:47]

changed to NoIdentifier.singleton
done.

+        ? createUnnamedParameter()  // This happens in function types.
+        : definition.accept(this);
     if (currentDefinitions.metadata != null) {
       element.metadataInternal =
           resolution.resolver.resolveMetadata(element, node);
     }
     currentDefinitions = null;
     return element;
   }
 
   void validateName(Identifier node) {
     if (isOptionalParameter &&
         optionalParametersAreNamed &&
         Name.isPrivateName(node.source)) {
       reporter.reportErrorMessage(node, MessageKind.PRIVATE_NAMED_PARAMETER);
     }
   }
 
   void computeParameterType(FormalElementX element,
       [VariableElement fieldElement]) {
-    void computeFunctionType(FunctionExpression functionExpression) {
+    // Function-type as in `foo(int bar(String x))`
+    void computeInlineFunctionType(FunctionExpression functionExpression) {
       FunctionSignature functionSignature = SignatureResolver.analyze(
           resolution,
           scope,
           functionExpression.typeVariables,
           functionExpression.parameters,
           functionExpression.returnType,
           element,
           registry,
           defaultValuesError: MessageKind.FUNCTION_TYPE_FORMAL_WITH_DEFAULT);
       element.functionSignature = functionSignature;
     }
 
     if (currentDefinitions.type != null) {
       element.typeCache = resolveTypeAnnotation(currentDefinitions.type);
     } else {
       // Is node.definitions exactly one FunctionExpression?
       Link<Node> link = currentDefinitions.definitions.nodes;
       assert(invariant(currentDefinitions, !link.isEmpty));
       assert(invariant(currentDefinitions, link.tail.isEmpty));
       if (link.head.asFunctionExpression() != null) {
         // Inline function typed parameter, like `void m(int f(String s))`.
-        computeFunctionType(link.head);
+        computeInlineFunctionType(link.head);
       } else if (link.head.asSend() != null &&
           link.head.asSend().selector.asFunctionExpression() != null) {
         // Inline function typed initializing formal or
         // parameter with default value, like `C(int this.f(String s))` or
         // `void m([int f(String s) = null])`.
-        computeFunctionType(link.head.asSend().selector.asFunctionExpression());
+        computeInlineFunctionType(
+            link.head.asSend().selector.asFunctionExpression());
       } else {
         assert(invariant(currentDefinitions,
             link.head.asIdentifier() != null || link.head.asSend() != null));
         if (fieldElement != null) {
           element.typeCache = fieldElement.computeType(resolution);
         } else {
           element.typeCache = const DynamicType();
         }
       }
     }
@@ skipping 36 matching lines @@
           enclosingElement, currentDefinitions, name, initializer,
           isOptional: isOptionalParameter, isNamed: optionalParametersAreNamed);
     } else {
       parameter = new FormalElementX(
           ElementKind.PARAMETER, enclosingElement, currentDefinitions, name);
     }
     computeParameterType(parameter);
     return parameter;
   }
 
+  FormalElementX createUnnamedParameter() {
+    FormalElementX parameter;
+    assert(!createRealParameters);
+    parameter = new FormalElementX.unnamed(
+          ElementKind.PARAMETER, enclosingElement, currentDefinitions);
+    computeParameterType(parameter);
+    return parameter;
+  }
+
   InitializingFormalElementX createFieldParameter(
       Send node, Expression initializer) {
     InitializingFormalElementX element;
     Identifier receiver = node.receiver.asIdentifier();
     if (receiver == null || !receiver.isThis()) {
       reporter.reportErrorMessage(node, MessageKind.INVALID_PARAMETER);
       return new ErroneousInitializingFormalElementX(
           getParameterName(node), enclosingElement);
     } else {
       if (!enclosingElement.isGenerativeConstructor) {
@@ skipping 200 matching lines @@
     LinkBuilder<DartType> parameterTypes = new LinkBuilder<DartType>();
     for (FormalElement parameter in parameters) {
       parameterTypes.addLast(parameter.type);
     }
     List<DartType> optionalParameterTypes = const <DartType>[];
     List<String> namedParameters = const <String>[];
     List<DartType> namedParameterTypes = const <DartType>[];
     List<Element> orderedOptionalParameters =
         visitor.optionalParameters.toList();
     if (visitor.optionalParametersAreNamed) {
-      // TODO(karlklose); replace when [visitor.optinalParameters] is a [List].
+      // TODO(karlklose); replace when [visitor.optionalParameters] is a [List].
       orderedOptionalParameters.sort((Element a, Element b) {
         return a.name.compareTo(b.name);
       });
       LinkBuilder<String> namedParametersBuilder = new LinkBuilder<String>();
       LinkBuilder<DartType> namedParameterTypesBuilder =
           new LinkBuilder<DartType>();
       for (FormalElement parameter in orderedOptionalParameters) {
         namedParametersBuilder.addLast(parameter.name);
         namedParameterTypesBuilder.addLast(parameter.type);
       }
       namedParameters = namedParametersBuilder.toLink().toList(growable: false);
       namedParameterTypes =
           namedParameterTypesBuilder.toLink().toList(growable: false);
     } else {
-      // TODO(karlklose); replace when [visitor.optinalParameters] is a [List].
+      // TODO(karlklose); replace when [visitor.optionalParameters] is a [List].
       LinkBuilder<DartType> optionalParameterTypesBuilder =
           new LinkBuilder<DartType>();
       for (FormalElement parameter in visitor.optionalParameters) {
         optionalParameterTypesBuilder.addLast(parameter.type);
       }
       optionalParameterTypes =
           optionalParameterTypesBuilder.toLink().toList(growable: false);
     }
     FunctionType type = new FunctionType(
         element.declaration,
@@ skipping 35 matching lines @@
 /// variables of the function signature itself when its signature is analyzed.
 class FunctionSignatureBuildingScope extends TypeVariablesScope {
   @override
   final List<DartType> typeVariables;
 
   FunctionSignatureBuildingScope(Scope parent, this.typeVariables)
       : super(parent);
 
   String toString() => 'FunctionSignatureBuildingScope($typeVariables)';
 }