Re 'Text Files Defended'
(Not just to pick on Lisp and Smalltalk, two fine languages: how long did it take for a regex class to make it into Java? And a regex class is one significant affordance notch below regexps built into the language.)
Brian should take a look at CL-PPCRE, Edi Weitz's regex package for Common Lisp. The great thing about lisp, of course, is that the user can build the feature into the language, not just introduce a class -- and you get performance that's as good as or better than Perl's regular expression engine.