Re: Ann: regex pack

On 14/09/2013, at 7:49 AM, Michael Hendricks wrote:

> I love DCGs as much as the next Prolog fan, but sometimes a tiny regular
> expression will do the job.  Or perhaps regular expressions are part of
> your app's UI.  Anyway, this
> pack<http://www.swi-prolog.org/pack/list?p=regex>supports many
> features of Perl compatible regex (see link for full support).

Oh dear.  The huge merit of regular expressions is that they take
linear time.  The huge defect of Perl irregular expressions is
that they can take exponential time.

Already with POSIX regular expressions I've found it easier to
write a DCG than to debug a mass of backslashes; Perl makes it
an order of magnitude worse.

If accepting regular expressions of a particular kind is part of
an interface that you have to implement, you don't have much choice.

Apart from that, if you can plug re2 in, why would you want
anything else?

Didn't Peter Schachte write a regular expression library for Prolog?