Resynthesize FunctionType(s) from Kernel.

pkg/analyzer/lib/src/kernel/resynthesize.dart

 // Copyright (c) 2017, 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.
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_ast_factory.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/element.dart';
@@ skipping 400 matching lines @@
   }
 
   @override
   LibraryElement getLibrary(String uriStr) {
     return _resynthesizer.getLibrary(uriStr);
   }
 
   DartType getType(ElementImpl context, kernel.DartType kernelType) {
     if (kernelType is kernel.DynamicType) return DynamicTypeImpl.instance;
     if (kernelType is kernel.VoidType) return VoidTypeImpl.instance;
+
     if (kernelType is kernel.InterfaceType) {
       return _getInterfaceType(context, kernelType.className.canonicalName,
           kernelType.typeArguments);
     }
+
     if (kernelType is kernel.TypeParameterType) {
       kernel.TypeParameter kTypeParameter = kernelType.parameter;
       return _getTypeParameter(context, kTypeParameter).type;
     }
+
+    if (kernelType is kernel.FunctionType) {
+      var functionElement = new FunctionElementImpl.synthetic([], null);
+      functionElement.enclosingElement = context;
+
+      functionElement.typeParameters = kernelType.typeParameters.map((k) {
+        return new TypeParameterElementImpl.forKernel(functionElement, k);
+      }).toList(growable: false);
+
+      functionElement.parameters = ParameterElementImpl.forKernelParameters(
+          functionElement,
+          kernelType.requiredParameterCount,
+          kernelType.positionalParameters
+              .map((t) => new kernel.VariableDeclaration(null, type: t))
+              .toList(),
+          kernelType.namedParameters
+              .map((t) => new kernel.VariableDeclaration(t.name, type: t.type))
+              .toList());
+
+      functionElement.returnType =
+          getType(functionElement, kernelType.returnType);
+      return functionElement.type;
+    }
+
     // TODO(scheglov) Support other kernel types.
     throw new UnimplementedError('For ${kernelType.runtimeType}');
   }
 
   /**
    * Return the [ElementImpl] that corresponds to the given [name], or `null`
    * if the corresponding element cannot be found.
    */
   ElementImpl _getElement(kernel.CanonicalName name) {
     if (name == null) return null;
@@ skipping 97 matching lines @@
         for (var typeParameter in ctx.typeParameters) {
           if (typeParameter.name == name) {
             return typeParameter;
           }
         }
       }
     }
     throw new StateError('Not found $kernelTypeParameter in $context');
   }
 }