On Sun, Mar 3, 2013 at 5:33 PM, Brendan Eich <[email protected]> wrote:
> Bjoern Hoehrmann wrote:
>
>> * David Bruant wrote:
>>
>>> I've found myself multiple times in a situation where I needed the index
>>> of the first element responding to some conditions. I solved it the
>>> following way:
>>>
>>> var index;
>>> array.some(function(e, i){
>>> if(someCondition(e)){
>>> index = i;
>>> return false;
>>> }
>>>
>>> return true;
>>> })
>>>
>>
>> It's usually a bad idea to trigger side-effects from such callbacks. The
>> proper solution here would be having a suitable method available, like
>>
>> var index = array.findIndex(someCondition)**;
>>
>> as it is called in Haskell and C#.
>>
>
> Hi Bjoern, findIndex is indeed a missing Array generic. I'll see if we can
> get it on the agenda for the next TC39 meeting (coming up quickly,
> mid-March). Thanks,
>
Despite my previous message with a solution that relied on
array.reduce(...), the benefit of stopping the iteration (once the
predicate returns true) is objectively compelling.
Rick
>
> /be
>
>
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