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

[dave_the_m]

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.

[LanX]

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!

[Anonymous Monk]

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

[dave_the_m]

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.

[ikegami]

See Re^3: Mutable foreach list? (types of for) and Re^6: C-style for loop for a little more on the "for" optimisations.