Re: Help with regexp

[Andreas Politz]

tomas@tuxteam.de writes:

> On Tue, Dec 01, 2009 at 10:07:46PM +0100, Pascal J. Bourguignon wrote:
>> Xavier Maillard <xma@gnu.org> writes:
>> 
>> > Hi,
>> >
>> > I am trying to find the regexp that could match on these:
>> >
>> > "=>foo"
>
> [...]
>
>> "=>\\([^:]*\\(\\|:[^:]*\\(\\|:[^:]*\\)\\)\\)"
>
> Wow, Pascal. You have taught this old dog a new trick. Up to now, I
> hadn't thought of putting an alternative (i.e. "|") at the start of a
> parenthesized sub-expression. Thanks :-)
>
> -- tomás

Since this topic is more or less closed (modulo escaped delimiter), we
could use it to discuss the question, why using non-trivial Emacs regexp
makes one feel like Chomsky had just written his influential book on
grammars.

Vim, the other editor, has updated and extended it's regexp engine
frequently in it's version history, while Emacs regexp never seemed to
be on top of antibody's to-do list ?

Things I (won't) miss most:

- extreme backslasheritis
- no short aliases for important constructs :
  digits,symbol-constituents,newline,space
- no zero-width matches ; look(ahead|behind)

-ap