On Wed, Mar 5, 2014 at 11:19 AM, Domenic Denicola <
domenic at domenicdenicola.com> wrote:

>  Personally I think the more useful model to follow than
> `String.prototype.contains` is `Set.prototype.has`.
>
Now that you mention it, I completely agree.

Rick


>
>  ------------------------------
> *From:* es-discuss <es-discuss-bounces at mozilla.org> on behalf of Rick
> Waldron <waldron.rick at gmail.com>
> *Sent:* Wednesday, March 05, 2014 11:11
> *To:* Sebastian Zartner
> *Cc:* es-discuss
> *Subject:* Re: Array.prototype.contains
>
>
>
>
> On Wed, Mar 5, 2014 at 7:04 AM, Sebastian Zartner <
> sebastianzartner at gmail.com> wrote:
>
>>      But it seems the thread fizzled out a couple years ago, and
>>> Array.prototype.contains didn't seem to make its way into ES6. That seems
>>> odd, since we do have String.prototype.contains, and it seemed like it was
>>> desirable for DOM.
>>>
>>>  The DOM won't inherit from it directly, shall it?
>>>
>>
>>  Why not? A use case would be to check whether a specific node is within
>> a NodeList.
>>
>>>   It's also a standard utility function in several libraries.
>>>
>>>  Was it left out on purpose? If so, what was the justification?
>>>
>>> I predict code like this without it:
>>>
>>> ''.contains.call([1, 2, 3], 2);  // true
>>>
>>>  .indexOf === -1 works today for this use case and will continue to.
>>> I'd be happy to see !~arr.indexOf(el) disappear in favor of a use of
>>> .contains() though.
>>>
>>
>>  While .indexOf() just gets you the index of one item, .contains() could
>> even be extended to allow to check whether an array contains several items.
>> E.g.
>>
>>  .contains([1, 2, 3], [1, 3]) // true
>>  .contains([1, 2, 3], [1, 4]) // false
>>
>
>
>  String.prototype.contains already has a second parameter for "position"
> (similar to String.prototype.indexOf), for consistency an
> Array.prototype.contains should have the same second "fromIndex" parameter
> as Array.prototype.indexOf.
>
>  Rick
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20140305/106090d0/attachment.html>

Now that you mention it, I completely agree.