package Math::Base;
use strict; use warnings;
use overload (
    '""' => \&encode,
    '0+' => \&num,
    '-'  => \&minus,
    '+'  => \&add,
    '*'  => \&mul,
    '/'  => \&div,
);

my %hash;
my @chars     = (0..9,'A'..'Z','a'..'z',map{chr$_}32..47,58..64,91..96);
@hash{@chars} = 0..$#chars;

sub new {
    my ($class, $base, $value, $encoded) = @_;
    my $self = bless [$base, $value], $class;
    $self->decode if $encoded;
    $self;
}

sub rebase { $_[0]->[0] = $_[1] }
   
sub num { shift->[1] }
sub minus {
    my ($self, $other, $swap) = @_;
    my $result = $self->[1] - $other;
    $result = -$result if $swap;
    ref $result ? $result : bless [$self->[0],$result];
}
sub add {
    my ($self, $other, $swap) = @_;
    my $result = $self->[1] + $other;
    ref $result ? $result : bless [$self->[0],$result];
}
sub mul {
    my ($self, $other, $swap) = @_;
    my $result = $self->[1] * $other;
    ref $result ? $result : bless [$self->[0],$result];
}
sub div {
    my ($self, $other, $swap) = @_;
    my $result = $swap ? $other / $self->[1] : $self->[1] / $other;
    int(ref $result ? $result : bless [$self->[0],$result]);
}

sub encode {
    my $self = shift;
    my ($base,$num) = @$self;
    $num = shift if $_[0];
    my ($rem,@ret);
    while ($num) {
        push @ret, $chars[($rem = $num % $base)];
        $num -= $rem;
        $num /= $base;
    }
    return join '', reverse @ret;
}


sub decode {
    my $self = shift;
    my ($base, $str) = @$self;
    $str = shift if $_[0];
    my $num = 0;
    $num = $num * $base + $hash{$_} for $str =~ /./g;
    $self->[1] = $num;
}
1;
__END__