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

#~ my $cmptime = -abs(shift);
#~ my $cmptime = -3;
my $cmptime = -10;
printf "%10s cmptime %s\n", $], $cmptime;
my @array;
for my $power ( 8, 16,18 ) {
#~ for my $power ( 8, 16, 20, 24 ){
    @array = 1 .. ( 2**$power );
    print "2 ** $power == @{[int @array ]}\n";
    cmpthese(
        $cmptime, {
            map { ; $_ => __PACKAGE__->can( $_ ) }
            qw/ ffor fforc
            ifor imap mmap
            sffor sfforc sifor simap
            slic smap simap2
            /
        }
    );
}
exit;

sub mmap {
    my %hash = map { ; $array[$_] => $_ } 0 .. $#array;
    ();
}

sub imap {
    my $ix = 0;
    my %hash = map { ; $_ => $ix++ } @array;
    ();
}
sub slic { my %hash; @hash{@array} = 0 .. $#array; (); }

sub ffor {
    my %hash;
    for my $ix ( 0 .. $#array ) { $hash{ $array[$ix] } = $ix; }
    ();
}

sub fforc {
    my %hash;
    for( my $ix = 0 ; $ix < @array ; $ix++ ) { $hash{ $array[$ix] } = $ix; }
    ();
}

sub ifor {
    my %hash;
    my $ix = 0;
    $hash{$_} = $ix++ for @array;
    ();
}

## preSize
sub sffor {
    my %hash;
    keys( %hash ) = int @array;
    for my $ix ( 0 .. $#array ) { $hash{ $array[$ix] } = $ix; }
    ();
}

sub sfforc {
    my %hash;
    keys( %hash ) = int @array;
    for( my $ix = 0 ; $ix < @array ; $ix++ ) { $hash{ $array[$ix] } = $ix; }
    ();
}

sub sifor {
    my %hash;
    my $ix = 0;
    keys( %hash ) = int @array;
    $hash{$_} = $ix++ for @array;
    ();
}

sub smap {
    my %hash;
    keys( %hash ) = int @array;
    @hash{@array} = 0 .. $#array;
    ();
}

sub simap {
    my $i = 0;
    my %hash;
    keys( %hash ) = int @array;
    %hash = map { $_ => $i++ } @array;
    ();
}


sub simap2 {
    my $i = 0;
    my %hash;
    keys( %hash ) = int @array;
    %hash = map(( $_ => $i++ ), @array);
    ();
}

__END__