sub foo {
my ($s1, $s2) = @_;
my @s1 = split //, $s1;
my @s2 = split //, $s2;
foreach my $idx ( 0 .. $#s1 ) {
if ( $s1[$idx] eq chr(0) ) {
$s1[$idx] = $s2[$idx];
}
}
return join '', @s1;
}
####
#!/usr/bin/perl
use 5.6.0;
use strict;
use warnings FATAL => 'all';
use Benchmark qw( cmpthese );
my $s1 = join '', (do_rand(1) x 100_000);
my $s2 = join '', (do_rand(0) x 100_000);
cmpthese( -2, {
'split1' => sub { my $s3 = split1( $s1, $s2 ) },
'substr1' => sub { my $s3 = substr1( $s1, $s2 ) },
});
sub split1 {
my ($s1, $s2) = @_;
my @s1 = split //, $s1;
my @s2 = split //, $s2;
foreach my $idx ( 0 .. $#s1 ) {
if ( $s1[$idx] eq chr(0) ) {
$s1[$idx] = $s2[$idx];
}
}
return join '', @s1;
}
sub substr1 {
my ($s1, $s2) = @_;
for my $idx ( 0 .. length($s1) ) {
if ( substr($s1,$idx,1) eq chr(0) ) {
substr($s1, $idx, 1) = substr($s2, $idx, 1);
}
}
return $s1;
}
# This makes sure that $s1 has chr(0)'s in it and $s2 does not.
sub do_rand {
my $n = (shift) ? int(rand(255)) : int(rand(254)) + 1;
return chr( $n );
}
__END__
##
##
#!/usr/bin/perl
use 5.6.0;
use strict;
use warnings FATAL => 'all';
#use Test::More no_plan => 1;
use Benchmark qw( cmpthese );
my $s1 = do_rand(0, 100_000);
my $s2 = do_rand(1, 100_000);
my $expected = split1( \$s1, \$s2 );
cmpthese( -3, {
'avar2' => sub {
my $s3 = $s1; avar2( \$s3, \$s2 );
# is( $s3, $expected, "avar2" );
},
'moritz' => sub {
my $s3 = $s1; moritz( \$s3, \$s2 );
# is( $s3, $expected, "moritz" );
},
});
sub split1 {
my ($s1, $s2) = @_;
my @s1 = split //, $$s1;
my @s2 = split //, $$s2;
foreach my $idx ( 0 .. $#s1 ) {
if ( $s1[$idx] eq chr(0) ) {
$s1[$idx] = $s2[$idx];
}
}
$$s1 = join '', @s1;
}
sub avar2 {
my ($s1, $s2) = @_;
use bytes;
$$s1 =~ s/\0/substr $$s2, pos($$s1), 1/eg;
}
sub moritz {
my ($s1, $s2) = @_;
my $pos = 0;
while ( 0 < ( $pos = index $$s1, "\000", $pos ) ) {
substr( $$s1, $pos, 1 ) = substr( $$s2, $pos, 1 );
}
}
sub do_rand {
my ($min, $len) = @_;
my $n = "";
for (1 .. $len) {
$n .= chr( rand(255-$min)+$min )
}
return $n;
}
__END__