I\'m working on a parser for a C-style language, and for that parser I need the
ID: 646380 • Letter: I
Question
I'm working on a parser for a C-style language, and for that parser I need the regular expression that matches C-style /**/ comments. Now, I've found this expression on the web:
However, as you can see, this is a rather messy expression, and I have no idea whether it actually matches exactly what I want it to match.
Is there a different way of (rigorously) defining regular expressions that are easy to check by hand that they are really correct, and are then convertible ('compilable') to the above regular expression?
Explanation / Answer
If you are writing a parser, this kind of stuff is handled by the lexical analyzer. And there you can express this by regular expressions, or (as the flex examples I've seen show) just "escape into the underlying language" and finish off the job there. I.e., on seeing /* just skip ahead until you find */ (a DFA for this is easy to build, and from there a C fragment is simple to write).