Re: [PATCH] wip: change ISSPACE to use ascii whitespace check.

Alejandro Colomar via Mutt-dev <[email protected]> Thu, 19 Feb 2026 01:52:57 +0100

Newsgroups	gmane.mail.mutt.devel
Message-ID	<aZZeW3cd7YkEr4lu@devuan>

On 2026-02-18T23:21:34+0100, Alejandro Colomar wrote:
> Hi Crystal,
> 
> On 2026-02-18T21:58:24+0000, Crystal Kolipe via Mutt-dev wrote:
> > On Wed, Feb 18, 2026 at 03:29:57PM +0100, Alejandro Colomar via Mutt-dev wrote:
> > > BTW, with the macros shown above, one could implement:
> > > 
> > > 	#define streq(a,b)  (strcmp(a,b) == 0)
> > > 
> > > 	#define isspace_c(c)            (!streq(strchrnul(MUTT_CTYPE_SPACE_C, c), ""))
> > > 	#define isspace_rfc5322_fws(c)  (!streq(strchrnul(MUTT_CTYPE_RFC5322_FWS, c), ""))
> > > 
> > > Although, in general, using the strspn(3) family of functions directly
> > > seems more ergonomic.
> > 
> > Note that strchrnul() is not available natively on OpenBSD.
> 
> D'oh!  Well, I guess we could add it as a fallback there.
> I hope POSIX takes this API eventually.
> 
> Here's a naive definition:
> 
> 	char *
> 	strchrnul(const char *s, int c)
> 	{
> 		char  *p;
> 
> 		p = strchr(s, c);
> 		if (p == NULL)
> 			return (char *) s + strlen(s);
> 		return p;

This can be compacted into a one-liner:

		return strchr(s, c) ?: (char *) s + strlen(s);

All compilers that I know, support '?:'.  It will be discussed for
standardization next month.

> 	}
> 
> Here's another one, which might be more or less readable:
> 
> 	char *
> 	strchrnul(const char *s, int c)
> 	{
> 		char  r[2] = {c, '\0'};
> 
> 		return (char *) s + strcspn(s, r);
> 	}
> 
> Disclaimer: I haven't tested these yet.
> 
> 
> Have a lovely night!
> Alex
> 
> -- 
> <https://www.alejandro-colomar.es>



-- 
<https://www.alejandro-colomar.es>

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