Add fromList constructor to typeddata typed lists.

Add fromList constructor to typeddata typed lists.

It seems that creating a typed array from a normal
list is something that is done fairly frequently.
It therefore seems to make sense to add the fromList
convenience constructor.

R=asiva@google.com,iposva@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=21325

[Anton Muhin, 2013-04-10 13:32:19]

DBC

https://codereview.chromium.org/13834008/diff/1/runtime/lib/typeddata.dart
File runtime/lib/typeddata.dart (right):

https://codereview.chromium.org/13834008/diff/1/runtime/lib/typeddata.dart#ne...
runtime/lib/typeddata.dart:16: /* patch */ factory Int8List.fromList(List<int>
elements) {
might be too esoteric, but why not

=> new _Int8Array(elements.length)..setRange(0, elements.length, elements)

[Mads Ager (google), 2013-04-10 13:34:23]

https://codereview.chromium.org/13834008/diff/1/runtime/lib/typeddata.dart
File runtime/lib/typeddata.dart (right):

https://codereview.chromium.org/13834008/diff/1/runtime/lib/typeddata.dart#ne...
runtime/lib/typeddata.dart:16: /* patch */ factory Int8List.fromList(List<int>
elements) {
On 2013/04/10 13:32:19, Anton Muhin wrote:
> might be too esoteric, but why not
> 
> => new _Int8Array(elements.length)..setRange(0, elements.length, elements)

Yeah, I had a variation on that one but didn't like it much. :-)

[siva, 2013-04-11 22:32:21]

The code LGTM.

I have one question regarding mixing double types with non double types, i.e if
a new Int8List.fromList is done with a
List that has double objects in it, I understand this will
give errors in checked mode but I hope it won't cause a VM
assertion in non checked mode.
It would be nice if we can add a test for this condition, I
understand it will cause issues in checked mode.
Maybe you could a test which we skip in checked mode.

[Ivan Posva, 2013-04-12 04:44:00]

On 2013/04/11 22:32:21, siva wrote:
> The code LGTM.
> 
> I have one question regarding mixing double types with non double types, i.e
if
> a new Int8List.fromList is done with a
> List that has double objects in it, I understand this will
> give errors in checked mode but I hope it won't cause a VM
> assertion in non checked mode.
> It would be nice if we can add a test for this condition, I
> understand it will cause issues in checked mode.
> Maybe you could a test which we skip in checked mode.

You will get exceptions in either case, checked mode or not. In non-checked mode
they depend on which typed list you are dealing with. In checked mode it is
right at the []= access.

-Ivan

[Mads Ager (google), 2013-04-12 05:46:31]

On 2013/04/12 04:44:00, Ivan Posva wrote:
> On 2013/04/11 22:32:21, siva wrote:
> > The code LGTM.
> > 
> > I have one question regarding mixing double types with non double types, i.e
> if
> > a new Int8List.fromList is done with a
> > List that has double objects in it, I understand this will
> > give errors in checked mode but I hope it won't cause a VM
> > assertion in non checked mode.
> > It would be nice if we can add a test for this condition, I
> > understand it will cause issues in checked mode.
> > Maybe you could a test which we skip in checked mode.
> 
> You will get exceptions in either case, checked mode or not. In non-checked
mode
> they depend on which typed list you are dealing with. In checked mode it is
> right at the []= access.
> 
> -Ivan

It is a good idea to add tests that mix the Float and Int arrays and check that
you get exceptions. I will do that. Thanks!

[Mads Ager (google), 2013-04-12 06:08:05]

Committed patchset #2 manually as r21325 (presubmit successful).

[Ivan Posva, 2013-04-12 16:21:35]

https://codereview.chromium.org/13834008/diff/1/runtime/lib/typeddata.dart
File runtime/lib/typeddata.dart (right):

https://codereview.chromium.org/13834008/diff/1/runtime/lib/typeddata.dart#ne...
runtime/lib/typeddata.dart:18: for (int i = 0; i < elements.length; i++)
result[i] = elements[i];
Curly braces.

https://codereview.chromium.org/13834008/diff/1/runtime/lib/typeddata.dart#ne...
runtime/lib/typeddata.dart:44: for (int i = 0; i < elements.length; i++)
result[i] = elements[i];
Ditto here and below.

[Mads Ager (google), 2013-04-15 06:00:06]

Thanks Ivan! Changes addressed and landed in separate changelist.

https://codereview.chromium.org/13834008/diff/1/runtime/lib/typeddata.dart
File runtime/lib/typeddata.dart (right):

https://codereview.chromium.org/13834008/diff/1/runtime/lib/typeddata.dart#ne...
runtime/lib/typeddata.dart:18: for (int i = 0; i < elements.length; i++)
result[i] = elements[i];
On 2013/04/12 16:21:35, Ivan Posva wrote:
> Curly braces.

Done.

https://codereview.chromium.org/13834008/diff/1/runtime/lib/typeddata.dart#ne...
runtime/lib/typeddata.dart:44: for (int i = 0; i < elements.length; i++)
result[i] = elements[i];
On 2013/04/12 16:21:35, Ivan Posva wrote:
> Ditto here and below.

Done.