On Saturday, 7 December 2019 at 15:57:14 UTC, Jonathan M Davis
wrote:
There may have been some tweaks to std.encoding here and there,
but for the most part, it's pretty ancient. Looking at the
history, it's Seb who marked some if it as being a replacement
for std.utf, which is just plain wrong.
Ouch! I must say it was a surprise to read, precisely because
std.encoding seemed weird and clunky. Good to know that it's
misleading.
Unfortunately that adds to the list I have of weirdly misleading
docs that seem to have crept in over the last months/years :-(
std.utf.validate does need a replacement, but doing so gets
pretty complicated. And looking at std.encoding.isValid, I'm
not sure that what it does is any better from simply wrapping
std.utf.validate and returning a bool based on whether an
exception was thrown.
Unfortunately I'm dealing with a use case where exception
throwing (and indeed, anything that generates garbage) is
preferred to be avoided. That's why I was looking for a function
that returned a bool ;-)
Depending on the string, it would actually be faster to use
validate, because std.encoding.isValid iterates through the
entire string regardless. The way it checks validity is also
completely different from what std.utf does. Either way, some
of the std.encoding internals do seem to be an alternate
implementation of what std.utf has, but outside of std.encoding
itself, std.utf is what Phobos uses for UTF-8, UTF-16, and
UTF-32, not std.encoding.
Thanks -- good to know.
I did do a PR at one point to add isValidUTF to std.utf so that
we could replace std.utf.validate, but Andrei didn't like the
implementation, so it didn't get merged, and I haven't gotten
around to figuring out how to implement it more cleanly.
Thanks for the attempt, at least! While I get the reasons it was
rejected, it feels a bit of a shame -- surely it's easier to do a
more major under-the-hood rewrite with the public API (and tests)
already in place ... :-\
