Re^3: counting backward (optimize foreach reverse low .. high

AFAIK for( @f ) is optimized to act like an iterator without expanding and caching the list.

But in for(reverse @f ) there is no for-context which helps reverse to act differently.

I'm to lazy for benchmarks (we had them before), but this was surely not fixed in 5.8.8

Cheers Rolf

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Re^4: counting backward (optimize foreach reverse low .. high by dave_the_m (Monsignor) on Mar 02, 2013 at 15:35 UTC
`for(reverse @f)` has been optimised not to expand the array since 5.10.0. Dave.	[reply] [d/l]
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]
Re^6: counting backward (optimize foreach reverse low .. high by dave_the_m (Monsignor) on Mar 02, 2013 at 17:37 UTC
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]
Re^6: counting backward (optimize foreach reverse low .. high by Anonymous Monk on Mar 02, 2013 at 16:24 UTC
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
See Re^3: Mutable foreach list? (types of for) and Re^6: C-style for loop for a little more on the "for" optimisations.	[reply]
Re^4: counting backward (optimize foreach reverse low .. high by Anonymous Monk on Mar 02, 2013 at 15:30 UTC
You're wrong	[reply]
Re^5: counting backward (optimize foreach reverse low .. high by LanX (Saint) on Mar 02, 2013 at 15:56 UTC
you too! Cheers Rolf	[reply]
Re^6: counting backward (optimize foreach reverse low .. high by Anonymous Monk on Mar 02, 2013 at 16:19 UTC
Maybe it's optimized for reversing arrays but not for reversing ranges: Kind of why I suggested optimizing it for ranges also	[reply]
Re^6: counting backward (optimize foreach reverse low .. high by Anonymous Monk on Mar 02, 2013 at 16:21 UTC
Nice try , but you're still wrong You sais But in for(reverse @f ) there is no for-context which helps reverse to act differently. That has nothing to do with ranges, and its still wrong	[reply]