Hmm... I find the 1 while s/\s$//; very interesting, but shocking as well. I guess I just blindly asumed that s/\s*$// was optimized.

Anyway, I, too, am working on a regex engine; mine is coded in C. It's a slow process for me, but I'm learning a lot--I haven't tried any optimizations yet, though, I'll have to finish before I start that : )

The 15 year old, freshman programmer,
Stephen Rawls