Hi,
Nikita Popov wrote:
There is a relatively simple (at least conceptually) way to make generators
rewindable: Remember the original arguments of the function, and basically
"re-invoke" it on rewind().
I'm wondering what people think about adding this functionality. I think
the main argument against it is that not all generators may behave sensibly
if you re-run their code -- there's probably a reasonable expectation that
an iterator will return the same sequence of values are rewinding,
something which we cannot guarantee with generators, but also don't enforce
with normal iterators either.
I am not sure if I think this is a good idea… for one thing it may not
be necessary to add support in core for this, because you could easily
write a userland Iterator class that wraps a generator-returning closure
and (re-)invokes it for you. If you do it yourself that way, it's clear
what's actually happening behind the scenes at least.
If it must be done, perhaps the code must explicitly opt-in to being
rewindable somehow? That would avoid problems with rewinding generators
which aren't designed for it.
Thanks,
Andrea
--
PHP Internals - PHP Runtime Development Mailing List
To unsubscribe, visit: http://www.php.net/unsub.php
