[patch/cla] Addition of array.unique to Dojo's array functions.

[Lightflowmark]

I think a function to return the unique values of an array, analagous to array_unique in PHP, would be a useful addition to Dojo's excellent array additions. It's a function I find regularly useful in other languages (and have just found a need for it in Javascript), and was surprised not to find it in Dojo. Code like

thisModule.unique= function (/* Array */ mixedArray)
  {
    testArr = new Array();
    uniqueArray = new Array();
    dojo.forEach(mixedArray,function(i){
      if (!testArr[i]) // value not seen yet?
      {
        testArr[i] = true;
        uniqueArray.push(i);
      }
    });
    return(uniqueArray);
  }

would seem to do it in an efficient way (this isn't my code, btw - ​http://blog.archive.jpsykes.com/212/unique-array-filter-in-dojo/index.htm).

[dante]

suggestions? seems d.l.f is the proper place for this overall, though the 'advanced' nature of d.l.f seems to make me want to make it support objects or something (unique members).

happy to add unit tests if you are ok w/ the function. otherwise close as wontfix. This likely doesn't belong in base, and there really isn't any other appropriate home for the functionality afaik.

if for whatever reason you would like it in base, i'm not sure I like the name 'unique' (as I'm proposing a more generic unique-id generator using the name dojo.unique)

[bill]

Marking as 1.5 to get rid of TBD's from the list of 1.4 bugs.

[Eugene Lazutkin]

Looks good. Needs tests. I think it should go in a separate file: dojox/lang/functional/ext-array.js --- I have more filters to add, and this will be the first one.

[dante]

see also #10768 for alt impl.

[dante]

did we still want to do this?

[Colin Snover]

1.8 is frozen. Move all enhancements to next release. If you need an exemption from the freeze for this ticket, contact me immediately.

[bill]

I think this will be handled in 2.0 if we base it on Lo-Dash, but otherwise perhaps worthwhile adding manually.

[dylan]

At this point, I think the recommendation would be to just use an ES6 Set or WeakSet? if this capability is really needed. If someone wants to backport to 1.x, we'll consider a patch. In Dojo 2, we've added a shim for Map, but we haven't added Set, ​https://github.com/dojo/core/tree/master/src