Implement iterable/repeat

[kasperisager]

This commit implements a repeat() function for indefinitely repeating a given iterator as specified in #13 and #16.

[kasperisager]

Should be all set now 👍

Note to self: Rebasing kills comments on GitHub 😕

[nikhedonia]

you are quick!
another alternative would be:

function* repeat(){
    if( Array.isArray(this) && this.length == 0 ){ return; }
    while(1){
        yield* this;
    }
}

But i'm not sure if there are any remaining cases which would let the loop spin without yielding...

[jussi-kalliokoski]

This doesn't look like it can handle non-restartable iterators, e.g.

function step (start, amount) {
  let current = start;
  while ( true ) {
    yield current;
    current += start;
  }
}

step(2, 2)::head(3)::repeat()::head(6)::to(Array).should.equal([2, 4, 6, 2, 4, 6]);

we should probably iterate over it while yielding and storing first, then keep yielding the stored items.

[kasperisager]

Yielding and storing the items of the iterator first and then indefinitely yielding from the stored array worked a treat.

[jussi-kalliokoski]

Thank you, great stuff! Keep it coming! ;) ❤️ 🎉