Re: exists $foo[7] and delete $foo[7]

[Ilya Zakharevich <ilya@math.ohio-state.edu>]

Gurusamy Sarathy writes:
> >Simiarly, I think you should have a clear statement about what
> >`exists' actually does for arrays.  Is  exists($a[$n]) equivalent to
> >($n >= 0 ? $n <= $#a : -$n <= @a), or what?
> 
> The effect of exists() on an array element cannot be represented using
> existing semantics, because the concept of "uninitialized array element"
> wasn't visible at the Perl level before.  But the concept is crucial
> for representing "sparseness" in arrays, which is needed by pseudo-hashes.

Thanks.  This is an important feature-depessimization wrt the older Perls.
Now a lot of new algos would suddently be possible...

Ilya

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References to:

Gurusamy Sarathy <gsar@ActiveState.com>

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