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Re: Pre-RFC: builtin:: functions for detecting numbers vs strings

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February 28, 2022 13:15
Re: Pre-RFC: builtin:: functions for detecting numbers vs strings
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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

 Philippe Bruhat (BooK)

 "Did I err?"      (Groo, in too many issues to count - ...and *YES* he did!)

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