I ran into a similar issue with regex syntax when attempting to incorporate it into Arcueid's reader. There seems to be no easy way to parse a regular expression using Perl-like /.../ syntax, not if you also want symbols that use /'s for other things, e.g. the division function. Arcueid thus uses for now, r/.../ for regular expressions, and that syntax could be more easily distinguished from other legitimate uses of symbols with a minimum of fuss.