Simple dungeon map reader and walker

Walker.rb

#!/usr/bin/env ruby -w

class Array
  def second
    self[1]
  end
end

class Symbol
  def to_i
    {:north => -1, :south => 1, :east => 1, :west => -1}[self]
  end
end

class Walker
  attr_reader :raw_dungeon, :dungeon

  def initialize raw_dungeon
    @raw_dungeon = raw_dungeon
    @dungeon     = @raw_dungeon.lines.map(&:chars).map(&:to_a)
    @position    = find_me
  end

  def find_me
    @dungeon.map do |line|
      line.to_a.index '&'
    end.each_with_index do |line, i|
      unless line.nil?
        return [i, line.to_i]
      end
    end

    return nil
  end

  def can_step? direction
    next_step = nil
    if direction == :north or direction == :south
      next_step = @dungeon[@position.first + direction.to_i][@position.second]
    elsif direction == :east or direction == :west
      next_step = @dungeon[@position.first][@position.second + direction.to_i]
    end

    return true if next_step == ' ' # next_step.steppable?
    return false
  end

  def step direction
    if can_step? direction
      @dungeon[@position.first][@position.second] = ' '

      if direction == :north or direction == :south
        @position = [@position.first + direction.to_i, @position.second]
      elsif direction == :east or direction == :west
        @position = [@position.first, @position.second + direction.to_i]
      end

      @dungeon[@position.first][@position.second] = '&'
      return @position
    end

    return nil
  end

  def look_at_dungeon
    puts @dungeon.join
  end
end


dungeon = <<-eodungeon
  ######################
  # &                  #
  #                    #
  #               @    #
  ######################
eodungeon

i = Walker.new dungeon
i.look_at_dungeon

9.times do
  %w( south east ).map(&:to_sym).each do |direction|
    if i.can_step? direction
      i.step direction
      puts '---'
      puts i.look_at_dungeon
    end
  end
end