http://qs1969.pair.com?node_id=1218895


in reply to Constants lists in array slices

I'm not sure what you expect. Both output lines are the same:

$ perl 1218891.pl 
Scalar value @row[FL2] better written as $row[FL2] at 1218891.pl line 
+17.
      e                         n w                
      e                         n w                
$ perl -v | head

This is perl 5, version 16, subversion 3 (v5.16.3) built for x86_64-li
+nux-thread-multi
(with 25 registered patches, see perl -V for more detail)

Copyright 1987-2012, Larry Wall

Perl may be copied only under the terms of either the Artistic License
+ or the
GNU General Public License, which may be found in the Perl 5 source ki
+t.

Complete documentation for Perl, including FAQ lists, should be found 
+on

[download]

Replies are listed 'Best First'.
Re^2: Constants lists in array slices
by LanX (Saint) on Jul 20, 2018 at 12:35 UTC
    > I'm not sure what you expect.

    of course it's the same output.

    The performance depends on the generated opcodes.

    I wasn't aware that constant folding of lists wasn't implemented in "oldish" Perl versions.

    Cheers Rolf
    (addicted to the Perl Programming Language :)
    Wikisyntax for the Monastery FootballPerl is like chess, only without the dice

[reply]
      The performance depends on the generated opcodes.

      Thanks - this was the bit I missed from the OP. It is now clear to me why this was of a concern to you.

[reply]

In Section Seekers of Perl Wisdom