File Coverage

blib/lib/StupidMarkov.pm

Criterion	Covered	Total	%
statement	6	47	12.7
branch	0	12	0.0
condition	0	3	0.0
subroutine	2	9	22.2
pod	6	6	100.0
total	14	77	18.1

#!/usr/bin/perl

package StupidMarkov;

use strict;
use warnings;

our $VERSION = "0.002";


sub new {
    my $proto = shift;
    my $class = ref($proto) || $proto;
    my $self = {
        "_probabilities" => {},
        "_prev_item" => undef,
        "_first_item" => undef,
        "_item_count" => 0,
        "_state" => undef,
    };

    bless $self, $class;
}

sub get_item_count {
    my $self = shift;
    return $self->{"_item_count"};
}

sub get_probabilities {
    my $self = shift;
    return $self->{"_probabilities"};
}

sub get_state {
    my $self = shift;
    return $self->{"_state"};
}

sub add_item {
    my $self = shift;
    my $item = shift;
    my $prev_item = $self->{"_prev_item"};
    my $probabilities = $self->{"_probabilities"};

    if (defined($prev_item)) {
        if (!defined($probabilities->{$prev_item})) {
            $probabilities->{$prev_item} = { $item => 1 };
        } else {
            $probabilities->{$prev_item}->{$item}++;
        }
    } else {
        $self->{"_first_item"} = $item;
    }

    $self->{"_prev_item"} = $item;
    $self->{"_item_count"}++;
}

sub _get_probable_next_item {
    my $self = shift;
    my $state = $self->{"_state"};
    my $probabilities = $self->{"_probabilities"};
    my $items = [];

    foreach my $next_state (keys(%{$probabilities->{$state}})) {
        foreach (0 .. $probabilities->{$state}->{$next_state}) {
            push(@{$items}, $next_state);
        }
    }

    return $items->[int(rand(@{$items}))];
}

sub get_next_item {
    my $self = shift;
    my $ext_state = shift;
    my $probabilities = $self->{"_probabilities"};

    if (defined($ext_state)) {
        return undef if (!defined($probabilities->{$ext_state}));
        $self->{"_state"} = $ext_state if (!defined($self->{"_state"}));
    } elsif (!defined($self->{"_state"})) {
        $self->{"_state"} = $self->{"_first_item"};
    }

    $self->{"_state"} = $self->_get_probable_next_item();
    return $self->{"_state"};
}


1;
__END__