In the Learning Perl Student Workbook (first edition), I had an exercise to match a Perl variable with a regular expression. This is supposed to be a simple exercise with a simple answer, so I excluded any special variables, such as $1 or ${^UNICODE}.
A long time ago in a Perl far, far away, when character classes were much smaller (see Know your character classes under different semantics), the pattern seems simple: Continue reading “Matching Perl identifiers is a lot harder now”