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Re: *foo{SCALAR}

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May 3, 2010 02:06
Re: *foo{SCALAR}
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On 30 April 2010 23:25, Zefram <> wrote:
> Nicholas Clark wrote:
>>I don't see the existing behaviour as a bug. It was quite deliberate.
> OK, it's not a bug.  It's still surprising.
>>That doesn't mean that behaviour shouldn't change. But it's a change of
>>behaviour, not a bug fix. And it will break some existing code.
> I think it should change.  Distinguishing between "variable by this
> name never referenced" and "variable by this name used and has default
> value" seems as useful for scalars as for arrays, hashes, and subs.
> I have a specific use case where the distinction is vitally important:
> Lexical::Import.  It would be generally useful to anything walking the
> package for debugging or other introspective use.
> As for breakage, note that I only advocate changing the glob deref
> operator "*foo{SCALAR}", not anything else that looks at GvSV.  So this
> won't break code using arbitrary operators that implicitly reference
> uninitialised scalars.  It'll only break code that explicitly retrieves
> *foo{SCALAR} and assumes that this is defined.  A non-zero amount of
> code, but small, and updating all that code seems a price worth paying
> for the added power and consistency.

FYI: There is code in DD specifically for this case.  Id expect any
capable data serializer to somewhat affected by this change.


perl -Mre=debug -e "/just|another|perl|hacker/"

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