Front page | perl.perl5.porters |
Postings from December 2002
Sorry about the delay in replying to the original question.
On Wed, Dec 11, 2002 at 11:28:48AM -0500, John Peacock wrote:
> Rafael Garcia-Suarez wrote:
> >%_ : placeholder for an SV that will get stringified. See sv_vcatpvfn() in
> >sv.c.
> >I can't find doc on this in the perl sources, but there a small paragraph
> >about it in the Cozens & Jenness.
I can't find any docs either. In fact, a straight grep on %_ in the
current sources is most unrewarding.
> Neat! Is it supported in 5.005???
Well, I had a grep in the 5.004_04 sources and it's in there quite a lot,
such as:
if (in_eval & 2)
warn("%_", msg);
else if (in_eval)
sv_catsv(GvSV(errgv), msg);
so I wondered what had happened to them all. The same piece of code is now:
if (PL_in_eval & EVAL_WARNONLY)
Perl_warn(aTHX_ "%"SVf, msg);
else
qerror(msg);
with this in perl.h
#ifndef SVf
# ifdef CHECK_FORMAT
# define SVf "p"
# else
# define SVf "_"
# endif
#endif
That doesn't seem to be in Devel::PPort (yet - patches welcome I guess)
I wonder how many parts of the perl core can be reduced slightly in size
by changing %s SvPV_nolen(sv) to %_ sv.
This would have the beneficial side effect of making the non-error code path
more direct, which might have a slight speed gain.
It's not in 5.003_07's sources, but I don't think anyone really supports that
any more.
Nicholas Clark