[cl-ppcre-devel] Quickly finding which alternative matched

[Harold Lee]

Edi Weitz wrote:
> However, are you really sure that the O(n) operation of looping
> through the registers is causing performance problems?  Have you
> profiled the code?  This looks like premature optimization to me.
>
> I'm pretty sure that whatever you'll do to "improve" this (filters or
> changing CL-PPCRE internally to return more information for example)
> you'll end up with something even slower.
>   
I am guilty of premature optimization at some level, but I think flex 
has set the bar high for scanner performance. I'll spend more time 
examining performance to see if this is really needed.
> That doesn't feel right.  I wouldn't create regex strings first just
> to parse them into s-expressions afterwards.  Why don't you start with
> s-expressions right away?
>   
I'll change COMBINE-REGEXPS to only call CL-PPCRE::PARSE-STRING for 
strings (and assume other data is an appropriate s-expression). I'd like 
to make this very similar to lex / flex in allowing users of this 
package to use regular expressions. I'm not worried about the parsing 
performance because I am doing this at compile time (via a macro, 
DEFSCANNER).