On Saturday, 5 September 2015 at 19:59:03 UTC, bitwise wrote:
Thanks for the explanation, but could you give an example of
how Stream would be rangified?
In the containers I'm writing, I'm returning a range from the
findAll() function instead of an array:
https://github.com/bitwise-github/d-containers/blob/master/collections/list.d#L901
I suppose any method returning an array/string could work like
this...Is this what you mean?
It doesn't seem like the entire Stream class should have to be
removed to make this change though.
I would have to study the problem to give a good answer. It's
been too long since I looked at the issue for me to remember the
finer details at this point. IIRC, a big part of the problem had
something to do with the fact that you essentially want a range
of bytes, but the underlying C APIs really give something more
like a range of a range of bytes, because you read the data into
a buffer rather than reading it a byte at a time (which gets even
further complicated by the fact that you generally want to reuse
that buffer and not allocate extra memory if you can avoid it).
On some level at least, that's the problem that byLine and
byChunk in std.stdio run into. I really don't remember the
details of what needed to be done differently for solid stream
support though.
But all of the stuff relating to getting objects out of a byte
stream can almost certainly be done by building it on top of a
range of bytes rather than having any of that talk to the disk or
generally care where the data comes from, and I very much doubt
that std.stream does anything like that. So, at minimum, what
std.stream does would have to be shifted so that all of the
transformations are done on top of ranges of ubyte rather than
talking to the disk or network stack or whatever. But I'd have to
go digging through the code to even know what std.stream does
right now, and I don't have the time right now to figure out how
it should work. It's been discussed before, and it was decided
that what's there was not what we wanted, though how far off it
is, I really don't know other than the fact that it's not
range-based. Any stream solution should be consuming and
producing ranges and should be agnostic to wherever the data
comes from unless it has a _really_ good reason not to be.
Steven Schveighoffer has been working off and on on a replacement
for std.stdio which supports streams and cleans up some of the
uglier things with std.stdio.File, so we may get something out of
that at some point, but he has yet to get far enough with it to
actually present it for review and possible inclusion in Phobos.
However, I haven't heard of any other work being done on streams,
and it seems like everyone's simply making do without, for better
or worse.
- Jonathan M Davis
