Support for dart:typed_data

tool/input_sdk/private/operations.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.
 
 /// This library defines runtime operations on objects used by the code
 /// generator.
 part of dart._runtime;
 
 _canonicalFieldName(obj, name, args, displayName) => JS('', '''(() => {
   $name = $canonicalMember($obj, $name);
@@ skipping 147 matching lines @@
           isSubtype($actual, $StreamSubscription)) {
     console.warn('Ignoring cast fail from ' + $typeName($actual) +
       ' to ' + $typeName($type));
     return true;
   }
   return false;
 })()''');
 
 strongInstanceOf(obj, type, ignoreFromWhiteList) => JS('', '''(() => {
   let actual = $realRuntimeType($obj);
-  if ($isSubtype(actual, $type) || actual == $jsobject) return true;
+  if ($isSubtype(actual, $type) || actual == $jsobject ||
+      actual == $int && type == $double) return true;

[Jennifer Messerly, 2016/02/10 00:20:30]

should we put this logic in isSubtype?

at runtime we have no way of distinguishing between doubles and ints. For
example, if I have a List<double> it may contain ints too:

var list = <double>[1.0, 1.5, 2.0];
print(list.runtimeType); // List<double>
print(list[0].runtimeType); // int
print(list[1].runtimeType); // double
print(list[2].runtimeType); // int

Feels like it'd be more consistent to allow `int <: double` subtyping at
runtime.

Otherwise I think there are places we might call subtype instead of
strongInstanceOf and get the wrong result...

[vsm, 2016/02/11 22:36:06]

I thought about doing that, but it's a bigger change.  E.g.,: this throws (in
checked mode) today on the VM and dart2js:

void main() {
  List l1 = <int>[1, 2];

  List<double> l2 = l1;
  print(l2);
}

I do agree that it's more consistent though with how we (and dart2js) treat
numbers.

   if ($ignoreFromWhiteList == void 0) return false;
   if ($isGroundType($type)) return false;
   if ($_ignoreTypeFailure(actual, $type)) return true;
   return false;
 })()''');
 
 instanceOfOrNull(obj, type) => JS('', '''(() => {
   if (($obj == null) || $strongInstanceOf($obj, $type, true)) return true;
   return false;
 })()''');
@@ skipping 242 matching lines @@
     constructor(dartIterator) {
       this.dartIterator = dartIterator;
     }
     next() {
       let i = this.dartIterator;
       let done = !i.moveNext();
       return { done: done, value: done ? void 0 : i.current };
     }
   }
 ''');