On Thu, Jul 25, 2013 at 8:44 AM, Claus Reinke <[email protected]> wrote: > I do not understand why (1) iterators are specified using a self-updating > API when a functional API would seem preferable, or why (2) generators are > linked to functions, when block-level generators would seem to be sufficient > and less complex. In some more detail: > > 1. Why do iterators have an imperative API? > > As currently specified, an Iterator's next returns a {done,value} pair > (ItrResult), updating the Iterator in place. A functional alternative > would have next return a {done,value,next} triple, leaving the original > Iterator unmodified. > It seems a lot easier to implement the imperative API in terms of > the functional one than the other way round, if one needed both. In > practice, I do not see any advantage to forcing an imperative API.
The imperative API is more performant in general, as it doesn't require the allocation of a new iterable object at every iteration. (I also prefer the functional approach, but I understand the arguments against it, and am fairly comfortable with languages that use imperative iterators, like Python and PHP.) ~TJ _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
