Compare regular expressions

[Adam Atlas]

On Apr 16, 1:50 pm, "Diez B. Roggisch" <d... at nospam.web.de> wrote:
> It's not. For the simplest of expressions one might come up with a
> relation between them, but even that would be hard. General case? No chance.

I wouldn't say there's 'no chance'. It would require external parsing,
for sure, but if anything, it may only be impossible for unusual
cases.

(Maybe I'll try this the next time I feel like writing parsers for fun
(which is surprisingly frequently).)