From: Dan Kohn <dan@...>
Date: 2006-01-03T11:42:57+09:00
Subject: is /#$/ a Ruby bug ?

p /#$/.match("#")[0]   # syntax error: unterminated string meets eof

The interpreter seems to interpret the first # as a comment but not the
second.

p /\#$/.match("#")[0]   # this works

This seems even odder:

p /[#$]/.match("#")[0]   # syntax error: compile error

p /[#\$]/.match("#")[0]   # we can escape the $ rather than the #

Shouldn't the interpreter ignore # within a Regexp /.../ unless there's
an x flag, a #{...} substitution, or a (?#...) comment?  Bug or feature?