On Wednesday, 27 July 2016 at 06:18:07 UTC, Sönke Ludwig wrote:
Am 26.07.2016 um 16:50 schrieb Johannes Pfau:
Am Mon, 25 Jul 2016 13:10:42 +0000
Hello,
I don't know if it is good practice or not, but sometimes it
make
life easier if you can put part of the data back into the
input
stream.
Writing data back to a stream is quite uncommon. The standard
way to
solve such problems is a peek method for buffered streams:
auto buf = stream.peek(length)
// You can now look at the data in buf
stream.read() will still return the data read by peek, no need
to write
data back into the stream.
With the notable exception of ungetc() for C's file streams.
But working on the byte level is something that ranges should
be used for in D's case and not streams, because the latter
tend to have a high call overhead. So such a feature could make
sense for a StreamInputRange/InputStreamRange wrapper.
Yes, and here is simple use-case for this: you have to process
input stream of data chunks mixed with separators from the
socket. To read only data and not separators, you can either ask
stream code to "read until separator", or you can read as much as
possible, then split on separator, return split-tail back to
stream and process split-head. Now all your reads from stream
will either start from the new data chunk or continue reading
from it.
Of course, application code can manage all this on its own, but
why not to help application programmer keep his code clean?