Ah, the Push down automata, I knew it would return to haunt me someday. Applied theory with Professor Decker...how I miss it q-; Thanks for this very helpful info John. Actually, my previous solution was on a similar track but instead of implementing a stack to push and pop I was doing something more hackish and just using a variable that would increment for each { and decrement for each } and return the brace that brought the var back to zero. This was a very hackish approach to the problem, and your stack suggestion has obvious advantages aside from its more poetic approach. I'll take a look at Parse::YAPP, sounds like a useful read. Aside from the fact that (??{}) sequence makes the regex code more compact than implementing a stack, are there advantages or disadvantages in terms of runtime, memory, etc? I guess what I'm asking is, if you had perl 5.7 running on your machine and a rainy afternoon to spend writing the best code you could, which technique would you choose? I am very interested in making my code the best it can be, since I hope others will find it useful and want to use it as well. Gotta work on my skills before that hallowed day, though.