What the (f)lex rule for a regex?

Question

I want to create a small language which allow entering regular expressions. I will be scanning with (f)lex.

Therefore I need the Lex rule for a regular expression. Has anyone done this before?

Answer 1

What is a "lex rule for a regular expression"? That makes no sense. A regular expression (in your language) is nothing that lex will recognize beyond a simple string literal constant. It would be impossible to define a lex rule for it. Any surrounding stuff (markers, etc.) might be tokenizable, such as Perl's s#regex#replace#flags