This is a little bit of a question but it may just be a feature request.

Is there a way to, from within a foreach, drop the element you are working with from the array.


Example:

@moo = (1 .. 10);
foreach (@moo)
{
  if ($_ % 2 > 0) { DROP();} # <----- is what I would LOVE
                             # to do
}

[download]

Such that the result would be @moo would be (2,4,6,8,10)

Yes I know I can there are all sorts of ways to get the same effect.

Grep:
@moo = grep {($_ % 2 > 0)?0:1;} @moo;

Or easier to add more complex code if you:
@moo = grep {; {if ($_ % 2 > 0){ 0; last; } 1;}}  @moo;
# PS why do I need that first ';' - I don't know but I do

For Loop:
for (my $i=0;$i<@moo;$i++)
{ if ($moo[$i] % 2 > 0)  {splice @moo, $i, 1;} }
# wow is this slow

[download]

But here is what I dislike - the inefficiency of having to use temporary variables or reassaining an entire list.

If a grep could work in place that would be the answer - but it can't. That pretty much doubles the amount of time it takes to work on the array - the assignment back to the original list.

Why is this important to me? I often find myself working with huge arrays. I would love to prune the data in a simple - yet readable away.

In reply to Foreach for array pruning? by spandox

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