Regex questions

Lähettäjä: Jeff Davis <jdavis-list@empires.org>
Aihe: regex questions

In python the regexes allow you to call a function instead of just
substitute the values (see <http://docs.python.org/lib/node111.html&gt; for
more details). That seems quite useful, is there something similar in ruby?

Also, let's say I want match anything between "a" and "b" unless it
contains the word "foo". I could write two regexes like so:

if str =~ /a(.*)b/ and str !~ /a(.*foo.*)b/

Is there a good way to make that kind of logic into one regex? Is there
some kind of "intersect" operator or a "not" operator?

There's /(?!foo)/x, but I can't think of any proper way to get it to
accept all other strings but the one specified. You could just invert your problem and reject any strings that *do* have a 'foo' between.

unless str =~ /a.*?foo.*?b/

If you need to, you can group to extract the non-foo part there.

Regards,
    Jeff Davis

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