Let's say I have the arrays @foo = 1 .. 5; and @bar = @foo[0..2]; I want to be able to splice(@bar, 1, 0, 6); and have is_deeply(\@foo, [1,6,2,3,4,5]); pass.

Basically, I want to have an array act as an alias to a sub-array of another array. If it helps, it can be a contiguous slice. I understand that slicing creates a completely new list, unrelated to the old one, so slicing as implemented isn't the answer.

I also know I can use tie for this, but I really want to avoid tie, if at all possible. The application1 of this is going into the refactoring of a heavily-used CPAN module, so performance is more important that a slight memory gain.

Is there a way to alias like I'm talking about? Or is this a Perl6-ism that isn't possible in Perl5? I would think that XS could provide a solution, but I don't know enough about XS to even make a stab at the feasibility of my crackpipe-dreams.

  1. Basically, I have an object which is a hashref that also contains an arrayref. I figured that I could make that into an arrayref as follows:
    • Index 0 is the size of the arrayref. (This would be maintained by hand.)
    • Index 1..M is the arrayref
    • Index M+1..N are the other attributes. They are accessed as so 
      sub foo {
    my $self = shift;
    return $self->[ $self->[0] + $foo_offset ];
}

      [download]
    • New attributes from subclasses can be added onto the end.
My criteria for good software:
  1. Does it work?
  2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?

In reply to (Expert) Splicing a slice by dragonchild

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