use strict;
use warnings;

use Benchmark       qw( cmpthese    );
use List::Util      qw( first       );
use List::MoreUtils qw( first_index );


my @short = qw( c a b c d b c d c );
my @med   = map { chr(ord('a') + rand(26)) } 0..100;
my @long  = map { chr(ord('a') + rand(26)) } 0..1000;


sub grep_alone {
   my ($item, @list) = @_;

   my $found = 0;
   @list = grep { $item ne $_ || $found++ } @list;

   return @list;
}

sub grep_splice {
   my ($item, @list) = @_;

   my ($index) = grep { $item eq $list[$_] } 0..$#list;
   splice(@list, $index, 1) if defined $index;

   return @list;
}

sub grep_splice_2 {
   my ($item, @list) = @_;

   my $found = 0;
   my ($index) = grep { $item eq $list[$_] && !($found++) } 0..$#list;
   splice(@list, $index, 1) if defined $index;

   return @list;
}

sub first_splice {
   my ($item, @list) = @_;

   my $index = first { $item eq $list[$_] } 0..$#list;
   splice(@list, $index, 1) if defined $index;

   return @list;
}

sub findex_splice {
   my ($item, @list) = @_;

   my $index = first_index { $item eq $_ } @list;
   splice(@list, $index, 1) if $index >= 0;

   return @list;
}


print("Verify:\n\n");
print('grep_alone:    ', (grep_alone    @short), "\n");
print('grep_splice:   ', (grep_splice   @short), "\n");
print('grep_splice_2: ', (grep_splice_2 @short), "\n");
print('first_splice:  ', (first_splice  @short), "\n");
print('findex_splice: ', (findex_splice @short), "\n");

print("\n\n");

print("\@short:\n\n");
cmpthese(-1, {
   grep_alone    => sub { grep_alone    @short; 1; },
   grep_splice   => sub { grep_splice   @short; 1; },
   grep_splice_2 => sub { grep_splice_2 @short; 1; },
   first_splice  => sub { first_splice  @short; 1; },
   findex_splice => sub { findex_splice @short; 1; },
});

print("\n\n");

print("\@med:\n\n");
cmpthese(-1, {
   grep_alone    => sub { grep_alone    @med; 1; },
   grep_splice   => sub { grep_splice   @med; 1; },
   grep_splice_2 => sub { grep_splice_2 @med; 1; },
   first_splice  => sub { first_splice  @med; 1; },
   findex_splice => sub { findex_splice @med; 1; },
});

print("\n\n");

print("\@long:\n\n");
cmpthese(-1, {
   grep_alone    => sub { grep_alone    @long; 1; },
   grep_splice   => sub { grep_splice   @long; 1; },
   grep_splice_2 => sub { grep_splice_2 @long; 1; },
   first_splice  => sub { first_splice  @long; 1; },
   findex_splice => sub { findex_splice @long; 1; },
});

print("\n\n");

print("The XS versions of List::Util and List::MoreUtils were used.\n");