#!/usr/bin/perl
use strict;
use warnings;
use Benchmark 'cmpthese';


my @list;
open (LIST, '<', 'list.rnd') or die "Unable to open list.rnd for reading : !";
while ( <LIST> ) {
    chomp;
    push @list, $_;
}

my $length = int(rand 240) + 10;
my $str_a = "";
$str_a .= ('a' .. 'z')[ rand 26] while length $str_a < $length;

sub expensive_function {
#    my ($str_a, $str_b) = @_;
#    my $foo;
#    for ( split // , $str_a . $str_b) {
#        $foo++;
#    }
}

cmpthese -5, {
    'tchn' => sub {
        use Inline C =>;
        for my $str_b ( @list ) {
            next if ! same_scan( $str_a, $str_b );
            expensive_function ( $str_a, $str_b );
        }
    },
    'LR' => sub {
        for my $str_b ( @list ) {
            next if index($str_a, substr($str_b, 0, 1));
            expensive_function ( $str_a, $str_b );
        }
    },
    'HB1' => sub {
        my ($a_1st, $rest) = split '', $str_a, 2;
        for my $str_b ( @list ) {
            my ($b_1st, $rest) = split '', $str_b, 2;
            next if $b_1st ne $a_1st;
            expensive_function ( $str_a, $str_b );
        }
    },
    'HB2' => sub {
        my $rev_a = reverse $str_a;
        my $a_1st = chop $rev_a;
        for my $str_b ( @list ) {
            my $rev_b = reverse $str_b;
            my $b_1st = chop $rev_b;
            next if $b_1st ne $a_1st;
            expensive_function ( $str_a, $str_b );
        }
    },
    'delim' => sub {
        my $fc = substr($str_a,0,1);
        for my $str_b ( @list ) {
            next if $str_b !~ /^$fc/;
            expensive_function ( $str_a, $str_b );
        }
    },
    'tye1' => sub {
        for my $str_b ( @list ) {
            next if ord $str_a != ord $str_b;
            expensive_function ( $str_a, $str_b );
        }
    },
    'tye2' => sub {
        my $fc = ord $str_a;
        for my $str_b ( @list ) {
            next if $fc != ord( $str_b );
            expensive_function ( $str_a, $str_b );
        }
    },
    'kval' => sub {
        my $fc = substr $str_a, 0, 1;
        for my $str_b ( @list ) {
            next if $fc ne substr $str_b, 0, 1;
            expensive_function ( $str_a, $str_b );
        }
    },
};
__END__
__C__
int same_scan(char* str1, char* str2)
{
  return str1[0] == str2[0] ? 1 : 0;
}