On 3/8/2014 5:58 PM, Piotr Szturmaj wrote:
W dniu 2014-03-08 02:09, H. S. Teoh pisze:
Having a way to auto-generate input range boilerplate, though, would be
really, *really* nice. Coroutine-style code would be ideal.
https://github.com/pszturmaj/dgenerators
Yea, there is that approach, which is nice in certain ways. I did the
same kinda thing a couple years ago[1], but your API appears much, much
nicer.
The unfortunate downside, though, is that as jerro demonstrated[2]
there's a high overhead when using fibers for iteration. It likely
wouldn't be an issue for some things, like IO, but for other things it
could be a problem.
So what we end up with is an unfortunate three-way choice anytime
someone needs a generator in D:
1. Give up on range compatibility (opApply)
2. Give up on straightforward implementation (input/forward range)
3. Give up on maximum performance (fiber-based coroutine range)
D's just dancing all around the ideal solution for generators without
ever actually hitting the mark. Which I find frustrating because I know
that's a target D's capable of nailing.
[1]
http://semitwist.com/articles/article/view/combine-coroutines-and-input-ranges-for-dead-simple-d-iteration
[2] http://forum.dlang.org/thread/jno6o5$qtb$1...@digitalmars.com
