Experiment with new function-type syntax.

pkg/compiler/lib/src/js_emitter/program_builder/field_visitor.dart

 // Copyright (c) 2015, 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.
 
 part of dart2js.js_emitter.program_builder;
 
 /**
  * [member] is a field (instance, static, or top level).
  *
  * [name] is the field name that the [Namer] has picked for this field's
  * storage, that is, the JavaScript property name.
  *
  * [accessorName] is the name of the accessor. For instance fields this is
  * mostly the same as [name] except when [member] is shadowing a field in its
  * superclass.  For other fields, they are rarely the same.
  *
  * [needsGetter] and [needsSetter] represent if a getter or a setter
  * respectively is needed.  There are many factors in this, for example, if the
  * accessor can be inlined.
  *
  * [needsCheckedSetter] indicates that a checked getter is needed, and in this
  * case, [needsSetter] is always false. [needsCheckedSetter] is only true when
  * type assertions are enabled (checked mode).
  */
-typedef void AcceptField(
+typedef AcceptField = (
     VariableElement member,
     js.Name name,
     js.Name accessorName,
     bool needsGetter,
     bool needsSetter,
-    bool needsCheckedSetter);
+    bool needsCheckedSetter) -> void;
 
 class FieldVisitor {
   final Compiler compiler;
   final Namer namer;
 
   JavaScriptBackend get backend => compiler.backend;
 
   FieldVisitor(this.compiler, this.namer);
 
   /**
@@ skipping 119 matching lines @@
         field is ClosureFieldElement;
   }
 
   bool canAvoidGeneratedCheckedSetter(VariableElement member) {
     // We never generate accessors for top-level/static fields.
     if (!member.isInstanceMember) return true;
     DartType type = member.type;
     return type.treatAsDynamic || type.isObject;
   }
 }