Brendan Eich (2014-10-06T03:44:47.000Z)
forbes at lindesay.co.uk (2016-02-01T13:01:16.080Z)
> This seems like it'd involve too much machinery and give unexpected results. > > I'd expect `instance.map(...)` to return another one of `instance`. That is, given a MapIterator `i`, I'd expect `i.map(...)` to be another MapIterator, and not a Map like you are proposing. Right, I was smoking something bad. The uniformity you describe is clearly the right solution. This means `Map.prototype.map` etc. -- or `%ItereablePrototype%.map` if not `Array.prototype.map` etc. -- are the eager collection-generic companions.