Re: Ann: regex pack

The latest release (v0.2.0) automatically unifies named regex captures with
corresponding variables in the surrounding scope.  For example,

  "Hi John" =~ "hi (?<Name>[a-z]+)"/i,
  Name == "John".

I'm enjoying it so far.  This is one more feature made possible by
prolog_load_context(variable_names,_).  Thanks again Jan for adding that.


-- 
Michael


On Fri, Sep 13, 2013 at 1:49 PM, Michael Hendricks <[email protected]>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).
>
> As the semantic version number indicates, the API is very early and will
> probably change. It currently uses =~ (as do Haskell and Perl), but that
> gives no access to captured values.  A YAP-compatible API would support
> captures so I might do that.  I'd also love to use
> prolog_load_context(variable_names, _) with regex named captures to
> automatically bind clause variables by name.
>
> I considered supporting quasiquotation (so one doesn't have to escape all
> the slashes), but decided for now that a regex that complex should probably
> be rewritten as a DCG anyway.
>
> The regular expression engine is currently a naive interpreter.  I partly
> did that so that I have an interpreter to play with as I experiment with
> some partial evaluation ideas.  It would be cool to partially evaluate the
> regex interpreter against a regex to generate fast, concise Prolog code.
>
> Last thought: I tried to design the library to support pluggable regex
> engines.  The idea is that one just adds a single line:
>
>     :- use_module(library(regex/engine/re2)).
>
> and your regular expressions are now handled by the re2 engine<https://code.google.com/p/re2/> (or
> PCRE or POSIX or ...).  Any interest in such things?  I've used similar
> tools to good effect in both Haskell and Perl.
>
> --
> Michael
>
-------------- next part --------------
HTML attachment scrubbed and removed