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? Michael Montague 26 Nov 2013 19:17 UTC

On 11/26/2013 10:24 AM, John Cowan wrote:
> Michael Montague scripsit:
>
>> I don't think that these are strong arguments for having
>> 'valid-sre?'. An implementation for which compiling is expensive,
>> could easily internally do the "is it valid"-type check before
>> compiling. Having it in the interface adds no functionality that is
>> not already easily available.
> It tells the compiler only to syntax-check and not go on to actually
> compile.  This is a very common feature in compilers: for example,
> in gcc the -fsyntax-only option activates this mode.  Sometimes
> all you want to know at present is whether something is syntactically valid.
>

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?'.