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Postings from November 2003
I notice this code in hv.c:
keysv = sv_2mortal(newSVsv(keysv));
I wonder why it's not written:
kevsv = sv_mortalcopy(keysv);
That would be this:
SV *
Perl_sv_mortalcopy(pTHX_ SV *oldstr)
{
register SV *sv;
new_SV(sv);
sv_setsv(sv,oldstr);
EXTEND_MORTAL(1);
PL_tmps_stack[++PL_tmps_ix] = sv;
SvTEMP_on(sv);
return sv;
}
Instead of this:
SV *
Perl_newSVsv(pTHX_ register SV *old)
{
register SV *sv;
if (!old)
return Nullsv;
if (SvTYPE(old) == SVTYPEMASK) {
if (ckWARN_d(WARN_INTERNAL))
Perl_warner(aTHX_ packWARN(WARN_INTERNAL), "semi-panic: attempt to dup freed string");
return Nullsv;
}
new_SV(sv);
if (SvTEMP(old)) {
SvTEMP_off(old);
sv_setsv(sv,old);
SvTEMP_on(old);
}
else
sv_setsv(sv,old);
return sv;
}
+
SV *
Perl_sv_2mortal(pTHX_ register SV *sv)
{
if (!sv)
return sv;
if (SvREADONLY(sv) && SvIMMORTAL(sv))
return sv;
EXTEND_MORTAL(1);
PL_tmps_stack[++PL_tmps_ix] = sv;
SvTEMP_on(sv);
return sv;
}
What's the necessity of all the games turning temp off and on again for
the code as used by hv.c?
Nicholas Clark
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