Introduce ParameterStructure

pkg/compiler/lib/src/elements/common.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.
 
 /// Mixins that implement convenience methods on [Element] subclasses.
 
 library elements.common;
 
 import '../common/names.dart' show Identifiers, Names, Uris;
 import '../common_elements.dart' show CommonElements;
 import '../util/util.dart' show Link;
+import 'entities.dart';
 import 'elements.dart';
 import 'resolution_types.dart'
     show ResolutionDartType, ResolutionInterfaceType, ResolutionFunctionType;
 
 abstract class ElementCommon implements Element {
   @override
   bool get isLibrary => kind == ElementKind.LIBRARY;
 
   @override
   bool get isCompilationUnit => kind == ElementKind.COMPILATION_UNIT;
@@ skipping 469 matching lines @@
     }
     return null;
   }
 
   void forEachBackendMember(void f(Element member)) {
     backendMembers.forEach(f);
   }
 }
 
 abstract class FunctionSignatureCommon implements FunctionSignature {
+  ParameterStructure _parameterStructure;
+
   ResolutionDartType get returnType => type.returnType;
 
   void forEachRequiredParameter(void function(Element parameter)) {
     requiredParameters.forEach(function);
   }
 
   void forEachOptionalParameter(void function(Element parameter)) {
     optionalParameters.forEach(function);
   }
 
@@ skipping 37 matching lines @@
       // There must be at least as many arguments as in the other signature, but
       // this signature must not have more required parameters.  Having more
       // optional parameters is not a problem, they simply are never provided
       // by call sites of a call to a method with the other signature.
       int otherTotalCount = signature.parameterCount;
       return requiredParameterCount <= otherTotalCount &&
           parameterCount >= otherTotalCount;
     }
     return true;
   }
+
+  ParameterStructure get parameterStructure {
+    if (_parameterStructure == null) {
+      int requiredParameters = requiredParameterCount;
+      int positionalParameters;
+      List<String> namedParameters;
+      if (optionalParametersAreNamed) {
+        namedParameters = type.namedParameters;
+        positionalParameters = requiredParameters;
+      } else {
+        namedParameters = const <String>[];
+        positionalParameters = requiredParameters + optionalParameterCount;
+      }
+      _parameterStructure = new ParameterStructure(
+          requiredParameters, positionalParameters, namedParameters);
+    }
+    return _parameterStructure;
+  }
 }
 
 abstract class MixinApplicationElementCommon
     implements MixinApplicationElement {
   Link<ConstructorElement> get constructors {
     throw new UnsupportedError('Unimplemented $this.constructors');
   }
 
   FunctionElement _lookupLocalConstructor(String name) {
     for (Link<Element> link = constructors; !link.isEmpty; link = link.tail) {
@@ skipping 80 matching lines @@
   @override
   bool get isBoolFromEnvironmentConstructor {
     return fromEnvironmentState == _FromEnvironmentState.BOOL;
   }
 
   @override
   bool get isStringFromEnvironmentConstructor {
     return fromEnvironmentState == _FromEnvironmentState.STRING;
   }
 }