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Re: regexp and valid-sre?

This page is part of the web mail archives of SRFI 115 from before July 7th, 2015. The new archives for SRFI 115 contain all messages, not just those from before July 7th, 2015.

Implementing Emacs in Scheme is a use case for this.
On Nov 26, 2013 11:17 AM, "Michael Montague" <mikemon@xxxxxxxxx> wrote:

> 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?'.