#!/usr/bin/perl -w

# State transition table
#
#      Current   Inputs      Next    Action
$next{'initial'}{'left' } = ['red',  sub { print "Red \n"} ];
$next{'initial'}{'right'} = ['blue', sub { print "Blue\n"} ];
$next{'red'}    {'left' } = ['blue', sub { print "Blue\n"} ];
$next{'red'}    {'right'} = ['end',  sub { print "End \n"} ];
$next{'blue'}   {'left' } = ['blue', sub { print "Blue\n"} ];
$next{'blue'}   {'right'} = ['red',  sub { print "Red \n"} ];
$next{'end'}    {'left' } = ['end',  sub { print "End \n"} ];
$next{'end'}    {'right'} = ['end',  sub { print "End \n"} ];

@arbitrary_inputs = qw/left left right left left right right left/;

$state = 'initial';
for (@arbitrary_inputs)
{
    $action = $next{$state}{$_}->[1];
    $action->();
    $state  = $next{$state}{$_}->[0];
}