Friendly RE engine warning

I'm currently working on my Shishi parser/RE engine project, which
shares some similarities with what you'll need from the Perl 6 RE
engine. One thing that troubles me about it is that it's a
recursive-descent traversal across a state machine, and if you implement
this in C without a great deal of cleverness, you'll end up with something
which makes it *very* easy for the end-user to blow the call stack and
segfault. I'm driving myself nuts trying to turn an inherently recursive
algorithm into an iterative one. :) (Maybe you could get better results
by converting a Perl RE 6 from NFA to a DFA and use a superposition of
states. But that messes with my head.)

-- 
<gnat> TorgoX: you're rapidly learning, I see, that XML is a fucking
piece of festering shit which has no more justification for walking
God's clean earth than a dung beetle with diarrhoea.

• Friendly RE engine warning by Simon Cozens