Support runtime check of function types.

tests/language/function_subtype_optional2_test.dart

Index: tests/language/function_subtype_optional2_test.dart
diff --git a/tests/language/function_subtype_optional2_test.dart b/tests/language/function_subtype_optional2_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..4ca61e8f8eb88b4871caa72150789022d99205d5
--- /dev/null
+++ b/tests/language/function_subtype_optional2_test.dart
@@ -0,0 +1,60 @@
+// Copyright (c) 2013, 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.
+// Dart test program for constructors and initializers.
+
+// Check function subtyping.
+
+import 'package:expect/expect.dart';
+
+class C<T> {}
+
+typedef void void_();
+typedef void void__int(int i);
+typedef void void___int([int i]);
+typedef void void___int2([int i]);
+typedef void void___Object([Object o]);
+typedef void void__int__int(int i1, [int i2]);
+typedef void void__int__int2(int i1, [int i2]);
+typedef void void__int__int_int(int i1, [int i2, int i3]);
+typedef void void___double(double d);
+typedef void void___int_int([int i1, int i2]);
+typedef void void___int_int_int([int i1, int i2, int i3]);
+typedef void void___Object_int([Object o, int i]);
+
+main() {
+  // Test ([int])->void <: ()->void.
+  Expect.isTrue(new C<void___int>() is C<void_>);
+  // Test ([int])->void <: (int)->void.
+  Expect.isTrue(new C<void___int>() is C<void__int>);
+  // Test (int)->void <: ([int])->void.
+  Expect.isFalse(new C<void__int>() is C<void___int>);
+  // Test ([int])->void <: ([int])->void.
+  Expect.isTrue(new C<void___int>() is C<void___int2>);
+  // Test ([Object])->void <: ([int])->void.
+  Expect.isTrue(new C<void___Object>() is C<void___int>);
+  // Test ([int])->void <: ([Object])->void.
+  Expect.isTrue(new C<void___int>() is C<void___Object>);
+  // Test (int,[int])->void <: (int)->void.
+  Expect.isTrue(new C<void__int__int>() is C<void__int>);
+  // Test (int,[int])->void <: (int,[int])->void.
+  Expect.isTrue(new C<void__int__int>() is C<void__int__int2>);
+  // Test (int)->void <: ([int])->void.
+  Expect.isFalse(new C<void__int>() is C<void___int>);
+  // Test ([int,int])->void <: (int)->void.
+  Expect.isTrue(new C<void___int_int>() is C<void__int>);
+  // Test ([int,int])->void <: (int,[int])->void.
+  Expect.isTrue(new C<void___int_int>() is C<void__int__int>);
+  // Test ([int,int])->void <: (int,[int,int])->void.
+  Expect.isFalse(new C<void___int_int>() is C<void__int__int_int>);
+  // Test ([int,int,int])->void <: (int,[int,int])->void.
+  Expect.isTrue(new C<void___int_int_int>() is C<void__int__int_int>);
+  // Test ([int])->void <: ([double])->void.
+  Expect.isFalse(new C<void___int>() is C<void___double>);
+  // Test ([int])->void <: ([int,int])->void.
+  Expect.isFalse(new C<void___int>() is C<void___int_int>);
+  // Test ([int,int])->void <: ([int])->void.
+  Expect.isTrue(new C<void___int_int>() is C<void___int>);
+  // Test ([Object,int])->void <: ([int])->void.
+  Expect.isTrue(new C<void___Object_int>() is C<void___int>);
+}