IMHO, a set(key, value) should return the value as it is when you address a value
var o = m.get(k) || m.set(k, v); // o === v // equivalent of var o = m[k] || (m[k] = v); // o === v a set with a key that returns `this` is a non case so almost as useless as the void return is. Usefulness comes with use cases ... except this jQuery chainability thingy that works fine for jQuery structure ( an ArrayLike Collection ) who asked for map.set(k0, v0).set(k1, v1).set(k2, v2) ? Or even map.set(k0,v0).get(k1) ? what are use cases for this? I am honestly curious about them because I cannot think a single one ... specially with the Set s.add(k0).add(k1).add(k2) ... this code looks weird inlined like this ... Thanks for your patience On Mon, Dec 3, 2012 at 2:04 PM, Rick Waldron <[email protected]> wrote: > > > > On Mon, Dec 3, 2012 at 4:28 PM, Andrea Giammarchi < > [email protected]> wrote: > >> I wonder what was the use case that convinced TC39 to return `this` with >> these methods. > > > Assuming you read the notes, I proposed the agenda item based on the best > practice of ensuring meaningful returns, and in the case of mutation > methods, |this| is a meaningful return. > > >> Accordingly, this will never work: >> var query = map.has('queried') ? map.get('queried') : >> map.set('queried', $('myquery')); >> > > Previously, map.set() had a useless void return... > > >> >> And it will be something like: >> var query = map.has('queried') ? map.get('queried') : >> map.set('queried', $('myquery')).get('queried'); >> >> which is ugly and I don't really understand where map.set(k0, v0).set(k1, >> v1).set(k2, v2) could be useful. >> > > Accessing the object post-mutation allows for more expressive use of the > API. > > > Rick > > >> Thanks for clarifications ( a use case would be already good ) >> >> br >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> >> >
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