regexp and valid-sre? Michael Montague (26 Nov 2013 03:34 UTC)
Re: regexp and valid-sre? Alex Shinn (26 Nov 2013 12:44 UTC)
Re: regexp and valid-sre? Peter Bex (26 Nov 2013 14:25 UTC)
Re: regexp and valid-sre? Michael Montague (26 Nov 2013 18:00 UTC)
Re: regexp and valid-sre? Peter Bex (26 Nov 2013 18:21 UTC)
Re: regexp and valid-sre? Michael Montague (26 Nov 2013 19:09 UTC)
Re: regexp and valid-sre? John Cowan (26 Nov 2013 18:24 UTC)
Re: regexp and valid-sre? Michael Montague (26 Nov 2013 19:17 UTC)
Re: regexp and valid-sre? Peter Bex (26 Nov 2013 19:23 UTC)
Re: regexp and valid-sre? Kevin Wortman (26 Nov 2013 19:52 UTC)
Re: regexp and valid-sre? Michael Montague (26 Nov 2013 19:59 UTC)
Re: regexp and valid-sre? Kevin Wortman (27 Nov 2013 23:33 UTC)
Re: regexp and valid-sre? John Cowan (27 Nov 2013 23:42 UTC)
Re: regexp and valid-sre? Arthur A. Gleckler (30 Nov 2013 14:55 UTC)
Re: regexp and valid-sre? Michael Montague (26 Nov 2013 18:02 UTC)
Re: regexp and valid-sre? John Cowan (26 Nov 2013 18:19 UTC)
Re: regexp and valid-sre? Michael Montague (26 Nov 2013 19:11 UTC)

Re: regexp and valid-sre? Peter Bex 26 Nov 2013 19:21 UTC

On Tue, Nov 26, 2013 at 11:17:41AM -0800, Michael Montague wrote:
> The only use case for 'valid-sre?' mentioned so far is Peter's
> interactive regular expression IDE. The C standard does not require the
> -fsyntax-only option. These do not seem like compelling arguments for
> including 'valid-sre?'.

Like I said, it's the primitive operation.  When all you want is
to check validity, compiling and handling an exception is very
inelegant and feels like jumping through unnecessary hoops.
It makes sense to provide the more primitive operations where
there's a chance someone might want to use those.

I haven't seen any particularly compelling arguments against
including it, either.  It's just a straightforward predicate,
and you can always implement it the way you indicate: try to
compile and return #t, and upon catching an exception return #f.

Cheers,
Peter
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