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Postings from March 2022
On Mon, 28 Feb 2022 at 14:15, Philippe Bruhat (BooK) <book@cpan.org> wrote: > > On Mon, Feb 28, 2022 at 02:15:42AM -0800, Darren Duncan wrote: > > On 2022-02-28 1:41 a.m., Dan Book wrote: > > > > Likewise, "0+$w" produces a number so its result is "originally" a > > number, so do that, or some other explicit cast operator like "int $w" > > etc, with values pulled from JSON to make them canonically numbers. -- > > Darren Duncan > > I think it all depends if a new SV was created. We've seen that some > string operations operate on the original string. I doubt this is the > case with assignment or numbers, so I expect the result of 0+ is indeed > a new original SV. > > Actually, let me follow Yves' suggestion and test my assumptions: > > $ perl -MDevel::Peek -e '$a="1";Dump($a); $b=0+$a; Dump($b)' > SV = PV(0x564576205ec0) at 0x564576230d80 > REFCNT = 1 > FLAGS = (POK,IsCOW,pPOK) > PV = 0x564576231b90 "1"\0 > CUR = 1 > LEN = 10 > COW_REFCNT = 1 > SV = IV(0x564576230e18) at 0x564576230e28 > REFCNT = 1 > FLAGS = (IOK,pIOK) > IV = 1 Right, so the action of: $new= 0+$old; converts it to a "number". It is the perl equivalent of: SV *new_sv= newSViv(SvIV(old_sv)); No function needed in builtin for this IMO. Note that the impact of the flag change would show if you added an additional Dump($a) at the end of your original invocation. cheers, Yves -- perl -Mre=debug -e "/just|another|perl|hacker/"Thread Previous | Thread Next