#!/usr/bin/perl
use strict;
use warnings;
use Benchmark 'cmpthese';
my $target = 'abc' x 1e4;
cmpthese(-1,{
'y' => sub { my $m = 0; $m = $target =~ y/a//; },
'=()=' => sub { my $m = 0; $m = () = $target =~ m/a/g; },
'while' => sub { my $m = 0; $m ++ while $target =~ m/a/g; },
'(?{})' => sub { my $m = 0; $target =~ m/a(?{ $m ++ })(*F)/g; },
'split_grep' => sub { my $m = 0;
$m = grep $_ eq 'a', split '', $target;
},
'split_by' => sub { my $m = 0;
$m = -1 + split 'a', 'x' . $target . 'x';
},
'chop' => sub { my $m = 0;
my $target2 = $target;
$m += ( 'a' eq chop $target2 ) while length $target2;
},
'chomp' => sub { my $m = 0;
my $target2 = $target;
local $/ = 'a';
0 while chomp $target2 and ++ $m or chop $target2;
},
'index' => sub { my $m = 0;
my $pat_len = length 'a';
my $pos = -$pat_len;
$m ++ while -1 < ( $pos = index $target, 'a', $pos + $pat_len );
},
'rindex' => sub { my $m = 0;
my $pat_len = length 'a';
my $pos = -1 + length $target;
$m ++ while -1 < ( $pos = rindex $target, 'a', $pos - $pat_len );
},
'substr' => sub { my $m = 0;
$m += ( 'a' eq substr $target, $_, 1 ) for 0 .. -2 + length $target;
},
});
####
perl-5.38.2
==========
Rate split_grep (?{}) substr chop chomp =()= while index rindex split_by tr / y
split_grep 214/s -- -4% -23% -36% -47% -68% -70% -77% -79% -99% -99%
(?{}) 222/s 4% -- -20% -34% -45% -67% -69% -77% -78% -98% -99%
substr 279/s 30% 26% -- -17% -31% -59% -61% -71% -73% -98% -99%
chop 336/s 57% 51% 20% -- -16% -50% -53% -65% -67% -98% -99%
chomp 403/s 88% 81% 44% 20% -- -40% -44% -58% -61% -97% -99%
=()= 673/s 214% 203% 141% 100% 67% -- -6% -29% -34% -95% -98%
while 718/s 235% 223% 157% 114% 78% 7% -- -24% -30% -95% -98%
index 948/s 342% 326% 240% 182% 135% 41% 32% -- -8% -93% -97%
rindex 1028/s 380% 362% 268% 206% 155% 53% 43% 8% -- -93% -97%
split_by 14354/s 6599% 6359% 5045% 4170% 3466% 2032% 1899% 1415% 1297% -- -59%
tr / y 34600/s 16047% 15470% 12301% 10192% 8496% 5039% 4718% 3551% 3267% 141% --
perl-5.32.0
==========
Rate split_grep (?{}) substr chomp chop =()= while rindex index split_by tr / y
split_grep 163/s -- -16% -45% -46% -53% -68% -78% -83% -83% -99% -100%
(?{}) 194/s 19% -- -34% -36% -44% -62% -73% -79% -79% -99% -99%
substr 296/s 82% 52% -- -2% -14% -42% -59% -68% -68% -98% -99%
chomp 302/s 85% 55% 2% -- -13% -41% -59% -68% -68% -98% -99%
chop 345/s 112% 78% 17% 14% -- -32% -53% -63% -63% -98% -99%
=()= 511/s 213% 163% 72% 69% 48% -- -30% -46% -46% -97% -99%
while 731/s 348% 276% 147% 142% 112% 43% -- -22% -22% -96% -98%
rindex 939/s 476% 383% 217% 211% 172% 84% 28% -- -0% -95% -97%
index 939/s 476% 383% 217% 211% 172% 84% 28% 0% -- -95% -97%
split_by 18553/s 11271% 9442% 6162% 6048% 5272% 3532% 2436% 1876% 1875% -- -46%
tr / y 34462/s 21022% 17623% 11531% 11319% 9878% 6645% 4611% 3570% 3568% 86% --
perl-5.20.1
==========
Rate split_grep substr chop =()= chomp (?{}) while index rindex split_by tr / y
split_grep 181/s -- -25% -38% -41% -41% -54% -73% -74% -74% -99% -99%
substr 241/s 33% -- -17% -21% -21% -38% -64% -65% -66% -99% -99%
chop 290/s 61% 20% -- -5% -5% -26% -57% -58% -59% -98% -99%
=()= 304/s 68% 26% 5% -- -1% -22% -55% -56% -57% -98% -99%
chomp 307/s 70% 27% 6% 1% -- -22% -54% -56% -56% -98% -99%
(?{}) 392/s 117% 62% 35% 29% 28% -- -42% -44% -44% -98% -99%
while 673/s 273% 179% 132% 121% 120% 72% -- -3% -4% -96% -98%
index 697/s 286% 189% 140% 129% 127% 78% 4% -- -1% -96% -98%
rindex 704/s 289% 192% 142% 131% 129% 80% 5% 1% -- -96% -98%
split_by 16747/s 9166% 6845% 5665% 5403% 5360% 4177% 2387% 2302% 2280% -- -51%
tr / y 34296/s 18876% 14124% 11707% 11170% 11081% 8658% 4994% 4819% 4773% 105% --
####
cmpthese(-1,{
'=()=' => sub { my $m = 0; $m = () = $target =~ m/ab/g; },
'while' => sub { my $m = 0; $m ++ while $target =~ m/ab/g; },
'(?{})' => sub { my $m = 0; $target =~ m/ab(?{ $m ++ })(*F)/g; },
'split_by' => sub { my $m = 0;
$m = -1 + split 'ab', 'x' . $target . 'x';
},
'chomp' => sub { my $m = 0;
my $target2 = $target;
local $/ = 'ab';
0 while chomp $target2 and ++ $m or chop $target2;
},
'index' => sub { my $m = 0;
my $pat_len = length 'ab';
my $pos = -$pat_len;
$m ++ while -1 < ( $pos = index $target, 'ab', $pos + $pat_len );
},
'rindex' => sub { my $m = 0;
my $pat_len = length 'ab';
my $pos = -1 + length $target;
$m ++ while -1 < ( $pos = rindex $target, 'ab', $pos - $pat_len );
},
});
####
perl-5.38.2
==========
Rate (?{}) chomp =()= while rindex index split_by
(?{}) 216/s -- -64% -70% -75% -78% -81% -96%
chomp 599/s 177% -- -17% -31% -40% -47% -90%
=()= 718/s 232% 20% -- -18% -28% -36% -88%
while 872/s 303% 46% 21% -- -13% -22% -85%
rindex 999/s 362% 67% 39% 15% -- -11% -83%
index 1120/s 418% 87% 56% 28% 12% -- -81%
split_by 5749/s 2559% 860% 701% 559% 475% 413% --
perl-5.32.0
==========
Rate (?{}) chomp =()= while index rindex split_by
(?{}) 228/s -- -59% -64% -75% -77% -78% -95%
chomp 555/s 143% -- -12% -39% -44% -47% -89%
=()= 627/s 175% 13% -- -31% -37% -41% -88%
while 913/s 300% 65% 46% -- -9% -13% -82%
index 999/s 338% 80% 59% 9% -- -5% -80%
rindex 1056/s 362% 90% 68% 16% 6% -- -79%
split_by 5046/s 2110% 810% 705% 452% 405% 378% --
perl-5.20.1
==========
Rate =()= (?{}) chomp rindex index while split_by
=()= 372/s -- -19% -22% -54% -54% -56% -96%
(?{}) 462/s 24% -- -3% -43% -43% -45% -95%
chomp 478/s 29% 4% -- -41% -41% -43% -95%
rindex 807/s 117% 75% 69% -- -1% -3% -92%
index 814/s 119% 76% 70% 1% -- -3% -92%
while 836/s 125% 81% 75% 4% 3% -- -91%
split_by 9752/s 2524% 2013% 1941% 1108% 1099% 1066% --