Support runtime check of function types.

tests/language/function_subtype_optional1_test.dart

Index: tests/language/function_subtype_optional1_test.dart
diff --git a/tests/language/function_subtype_optional1_test.dart b/tests/language/function_subtype_optional1_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..f66fe149c5e2711b94e112001952477f7a032d28
--- /dev/null
+++ b/tests/language/function_subtype_optional1_test.dart
@@ -0,0 +1,71 @@
+// 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';
+
+void void_() {}
+void void__int(int i) {}
+void void___int([int i]) {}
+void void___int2([int i]) {}
+void void___Object([Object o]) {}
+void void__int__int(int i1, [int i2]) {}
+void void__int__int2(int i1, [int i2]) {}
+void void__int__int_int(int i1, [int i2, int i3]) {}
+void void___double(double d) {}
+void void___int_int([int i1, int i2]) {}
+void void___int_int_int([int i1, int i2, int i3]) {}
+void void___Object_int([Object o, int i]) {}
+
+typedef void t_void_();
+typedef void t_void__int(int i);
+typedef void t_void___int([int i]);
+typedef void t_void___int2([int i]);
+typedef void t_void___Object([Object o]);
+typedef void t_void__int__int(int i1, [int i2]);
+typedef void t_void__int__int2(int i1, [int i2]);
+typedef void t_void__int__int_int(int i1, [int i2, int i3]);
+typedef void t_void___double(double d);
+typedef void t_void___int_int([int i1, int i2]);
+typedef void t_void___int_int_int([int i1, int i2, int i3]);
+typedef void t_void___Object_int([Object o, int i]);
+
+main() {
+  // Test ([int])->void <: ()->void.
+  Expect.isTrue(void___int is t_void_);
+  // Test ([int])->void <: (int)->void.
+  Expect.isTrue(void___int is t_void__int);
+  // Test (int)->void <: ([int])->void.
+  Expect.isFalse(void__int is t_void___int);
+  // Test ([int])->void <: ([int])->void.
+  Expect.isTrue(void___int is t_void___int2);
+  // Test ([Object])->void <: ([int])->void.
+  Expect.isTrue(void___Object is t_void___int);
+  // Test ([int])->void <: ([Object])->void.
+  Expect.isTrue(void___int is t_void___Object);
+  // Test (int,[int])->void <: (int)->void.
+  Expect.isTrue(void__int__int is t_void__int);
+  // Test (int,[int])->void <: (int,[int])->void.
+  Expect.isTrue(void__int__int is t_void__int__int2);
+  // Test (int)->void <: ([int])->void.
+  Expect.isFalse(void__int is t_void___int);
+  // Test ([int,int])->void <: (int)->void.
+  Expect.isTrue(void___int_int is t_void__int);
+  // Test ([int,int])->void <: (int,[int])->void.
+  Expect.isTrue(void___int_int is t_void__int__int);
+  // Test ([int,int])->void <: (int,[int,int])->void.
+  Expect.isFalse(void___int_int is t_void__int__int_int);
+  // Test ([int,int,int])->void <: (int,[int,int])->void.
+  Expect.isTrue(void___int_int_int is t_void__int__int_int);
+  // Test ([int])->void <: ([double])->void.
+  Expect.isFalse(void___int is t_void___double);
+  // Test ([int])->void <: ([int,int])->void.
+  Expect.isFalse(void___int is t_void___int_int);
+  // Test ([int,int])->void <: ([int])->void.
+  Expect.isTrue(void___int_int is t_void___int);
+  // Test ([Object,int])->void <: ([int])->void.
+  Expect.isTrue(void___Object_int is t_void___int);
+}