Re: Command Languages Versus Programming Languages

Janis Papanagnou <janis_papanagnou+ng@hotmail.com> writes:

[...]

Personally I think that writing bulky procedural stuff for something
like [0-9]+ can only be much worse, and that further abbreviations
like \d+ are the better direction to go if targeting a good interface.
YMMV.

Assuming that p is a pointer to the current position in a string, e is a
pointer to the end of it (ie, point just past the last byte) and -
that's important - both are pointers to unsigned quantities, the 'bulky'
C equivalent of [0-9]+ is

while (p < e && *p - '0' < 10) ++p;

That's not too bad. And it's really a hell lot faster than a
general-purpose automaton programmed to recognize the same pattern
(which might not matter most of the time, but sometimes, it does).