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Re^4: counting backward (optimize foreach reverse low .. high

by dave_the_m (Parson)
on Mar 02, 2013 at 15:35 UTC ( #1021432=note: print w/ replies, xml ) Need Help??


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 (Canon) 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 ...

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

    Cheers Rolf

      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.

      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

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

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