use warnings;
use strict;
use Data::Dump qw/dd pp/;
use Benchmark qw/cmpthese/;

# example output:
# 5.024001
#         Rate regex index split
# regex 9.64/s    --   -8%  -41%
# index 10.5/s    9%    --  -36%
# split 16.4/s   70%   56%    --

my $str = "\nFoo\n\nBar Quz\nBaz\nx" x 50000;

use constant TEST => 0;
my $expect = join "\0", split /\n/, $str;
$expect=~s/o/i/g;
#dd [split /\n/, $str], $expect;

dd $];
cmpthese(-5, {
    split => sub {
        my @lines;
        my @x = split /\n/, $str;
        #@x = map {$_} @x; # significant slowdown
        #for my $line (map {$_} split /\n/, $str) { # still fairly fas
+t
        for my $line (@x) {
            $line=~s/o/i/g;
            push @lines, $line;
        }
        if (TEST) { die pp(@lines) unless $expect eq join "\0", @lines
+ }
    },
    split2 => sub {
            my @lines;
            my @x = split "\n", $str; ### couple of percent
            #@x = map {$_} @x; # significant slowdown
            #for my $line (map {$_} split /\n/, $str) { # still fairly
+ fast
            for my $line (@x) {
                $line =~ tr/o/i/; ### big difference vs regex s///
                push @lines, $line;
            }
            if (TEST) { die pp(@lines) unless $expect eq join "\0", @l
+ines }
    },
    regex => sub {
        my @lines;
        pos($str)=0;
        #while ($str=~/^(.*)$/mgc) { # slower
        while ($str=~/\G(?|(.*?)\n|(.+)\z)/gc) {
            my $line = $1;
            $line=~s/o/i/g;
            push @lines, $line;
        }
        if (TEST) {
            die unless pos($str)==length($str);
            die pp(@lines) unless $expect eq join "\0", @lines;
        }
    },
    index => sub {
        my @lines;
        for ( my ($pos,$nextpos) = (0); $pos<length($str);
            $pos=$nextpos+1 ) {
                $nextpos = do { my $i=index($str,"\n",$pos);
                    $i<0?length($str):$i };
                my $line = substr $str, $pos, $nextpos-$pos;
                $line=~s/o/i/g;
                push @lines, $line
        }
        if (TEST) { die pp(@lines) unless $expect eq join "\0", @lines
+ }
    },
});
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