Implement new optional parameters syntax in the vm (issue 4290).

tests/language/named_parameters_type_test.dart

Index: tests/language/named_parameters_type_test.dart
===================================================================
--- tests/language/named_parameters_type_test.dart	(revision 12003)
+++ tests/language/named_parameters_type_test.dart	(working copy)
@@ -3,17 +3,21 @@
 // BSD-style license that can be found in the LICENSE file.
 // VMOptions=--enable_type_checks
 //
-// Dart test program for testing named parameters in type tests.
+// Dart test program for testing optional named parameters in type tests.
 
+// TODO(regis): The expected signatures below will change once we run this test
+// with --reject_named_argument_as_positional which is still too early to do at
+// this time.
+
 class NamedParametersTypeTest {
   static int testMain() {
     int result = 0;
     Function anyFunction;
-    void acceptFunNumOptBool(void funNumOptBool(num num, [bool b])) { };
-    void funNum(num num) { };
-    void funNumBool(num num, bool b) { };
-    void funNumOptBool(num num, [bool b = true]) { };
-    void funNumOptBoolX(num num, [bool x = true]) { };
+    void acceptFunNumOptBool(void funNumOptBool(num n, {bool b})) { };
+    void funNum(num n) { };
+    void funNumBool(num n, bool b) { };
+    void funNumOptBool(num n, {bool b: true}) { };
+    void funNumOptBoolX(num n, {bool x: true}) { };
     anyFunction = funNum;  // No error.
     anyFunction = funNumBool;  // No error.
     anyFunction = funNumOptBool;  // No error.
@@ -23,22 +27,22 @@
       acceptFunNumOptBool(funNum);  // No static type warning.
     } on TypeError catch (error) {
       result += 1;
-      Expect.stringEquals("(num, [b: bool]) => void", error.dstType);
+      Expect.stringEquals("(num, {b: bool}) => void", error.dstType);
       Expect.stringEquals("(num) => void", error.srcType);
     }
     try {
       acceptFunNumOptBool(funNumBool);  /// static type warning
     } on TypeError catch (error) {
       result += 10;
-      Expect.stringEquals("(num, [b: bool]) => void", error.dstType);
+      Expect.stringEquals("(num, {b: bool}) => void", error.dstType);
       Expect.stringEquals("(num, bool) => void", error.srcType);
     }
     try {
       acceptFunNumOptBool(funNumOptBoolX);  /// static type warning
     } on TypeError catch (error) {
       result += 100;
-      Expect.stringEquals("(num, [b: bool]) => void", error.dstType);
-      Expect.stringEquals("(num, [x: bool]) => void", error.srcType);
+      Expect.stringEquals("(num, {b: bool}) => void", error.dstType);
+      Expect.stringEquals("(num, {x: bool}) => void", error.srcType);
     }
     return result;
   }