Re^3: declaring lexical variables in shortest scope: performance?

> it's 50% slower

Do you mean you added the my $z=12; to both the subroutines and the lexical one became 50% slower? I can't reproduce that behaviour. Adding it to only one of the subs slows it (35% in my case), but then we are comparing apples and oranges.

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

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Re^4: declaring lexical variables in shortest scope: performance? by bliako (Monsignor) on Mar 31, 2020 at 11:58 UTC
I meant to say that comparing lexicals only: one with a `my $z;` inside the loop is so much slower. Even 35% is much here is the code: `use Benchmark 'cmpthese'; cmpthese(-2, { predecl => ' my $y; my $x; for $x (1..10000) { $y+=$x } #print "$y\n"; ', lexical => ' my $y; for my $x (1..10000) { $y+=$x } #print "$y\n"; ', }); __END__` [download] `Rate predecl lexical predecl 1836/s -- -54% lexical 3996/s 118% --` [download]	[reply] [d/l] [select]
Re^5: declaring lexical variables in shortest scope: performance? by LanX (Saint) on Mar 31, 2020 at 12:00 UTC
For loops do aliasing! Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply]
Re^6: declaring lexical variables in shortest scope: performance? by bliako (Monsignor) on Mar 31, 2020 at 12:14 UTC
what do you mean by aliasing? if you mean accessing complex structures `$x->{'a'}->{'b'}->[$loop_index]` , I always put the static part of the data structure outside the loop and use that "alias?" inside the loop	[reply] [d/l]
Re^7: declaring lexical variables in shortest scope: performance? by LanX (Saint) on Mar 31, 2020 at 12:31 UTC
Re^8: declaring lexical variables in shortest scope: performance? by bliako (Monsignor) on Mar 31, 2020 at 12:41 UTC
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