I'm a bit confused by this behaviour, and am unsure whether it needs
to be better documented, or perhaps is a bug.
int main() {
object buf = Stdio.Buffer("#44");
write("Matches: %O %O\n", buf->sscanf("#%2[4]"), (string)buf);
buf = Stdio.Buffer("#4");
write("Doesn't: %O %O\n", buf->sscanf("#%2[4]"), (string)buf);
buf = Stdio.Buffer("#44");
write("Matches: %O %O\n", buf->match("#%2[4]"), (string)buf);
buf = Stdio.Buffer("#4");
write("Doesn't: %O %O\n", buf->match("#%2[4]"), (string)buf);
}
When using sscanf, the successful match returns ({"44"}) and leaves
the buffer empty, and the unsuccessful match returns an empty array
and leaves the "4" in the buffer. This makes sense; the hash was
matched and consumed, but the 2-character requirement meant that
nothing was matched.
Using match instead produces a somewhat odd result though. If there's
enough text in the buffer, it returns "44" and leaves the buffer
empty; this corresponds to sscanf's behaviour. In the other case,
though, it returns "#%2[4]" (the pattern), and leaves "4" in the
buffer. Is this intentional?
(If the first character of the buffer isn't a hash, both return 0 and
leave the buffer unchanged. This behaviour is also correct. It's only
the partial match that seems curious.)
ChrisA
