in reply to Re^3: counting backward (optimize foreach reverse low .. high
in thread counting backward

for(reverse @f) has been optimised not to expand the array since 5.10.0.

Dave.

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Re^5: counting backward (optimize foreach reverse low .. high
by LanX (Saint) on Mar 02, 2013 at 15:52 UTC
    Maybe it's optimized for reversing arrays but not for reversing ranges:

    I had to stop the second version because the swapping started to freeze my system: 

    lanx@nc10-ubuntu:~$ perl -e'for my $i ( 0 .. 1e8 ) { $x*=-1; $x+=$i };
+print "$x\n"' 
50000000
lanx@nc10-ubuntu:~$ perl -e'for my $i ( reverse 0 .. 1e8 ) { $x*=-1; $
+x+=$i };print "$x\n"' 
^C^C^C
lanx@nc10-ubuntu:~$ perl -version

This is perl, v5.10.0 built for i486-linux-gnu-thread-multi

...

    [download]

    Reversing ranges was what BUK did, but AnoMonk replied with a reference to a fix for reversing arrays!

    Cheers Rolf

[reply]
[d/l]
      Maybe it's optimized for reversing arrays but not for reversing ranges:
      But the post of yours which I replied to explicitly showed @a as an example, not a range. I never claimed ranges were optimised, while you implied that arrays weren't.

      Dave.

[reply]

      Reversing ranges was what BUK did, but AnoMonk replied with a reference to a fix for reversing arrays!

      As a suggestion to fix range operator

[reply]
Re^5: counting backward (optimize foreach reverse low .. high
by ikegami (Patriarch) on Mar 02, 2013 at 20:46 UTC
[reply]

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