# see http://www.xs4all.nl/~weegen/eelis/analogliterals.xhtml
 
module AnalogLiterals
  class A < Struct.new(:dashes, :tildes, :pluses, :els)
    def -@; A.new(dashes+1, tildes, pluses, els); end
    def ~@; A.new(dashes, tildes+1, pluses, els); end
    def +@; A.new(dashes, tildes, pluses+1, els); end
    
    def -x; A.new(dashes+x.dashes+1, tildes+x.tildes, pluses+x.pluses, els+x.els); end
    def +x; A.new(dashes+x.dashes, tildes+x.tildes, pluses+x.pluses+1, els+x.els); end
    
    def length; (dashes-1)/2; end
    def width; (dashes-1)/2; end
    
    def height
      if els > 0
        pluses + (tildes-pluses-1)/3
      else
        (tildes+pluses)/2
      end
    end
    
    def depth; els; end
  end
 
  module Helpers
    I = A.new(0, 0, 0, 0)
    def o; A.new(0, 0, 0, 0); end
    L = A.new(0, 0, 0, 1)
  end
end
 
if __FILE__ == $0
  require 'test/unit'
  
  class AnalogLiteralsTest < Test::Unit::TestCase
    def test_line
      assert_equal 0, (I-I).length
      assert_equal 1, (I---I).length
      assert_equal 2, (I-----I).length
      assert_equal 3, (I-------I).length
    end
 
    def test_rect2x3
      assert_equal 2, rect2x3.width
      assert_equal 3, rect2x3.height
    end
    
    def test_cuboid6x6x3
      assert_equal 6, cuboid6x6x3.width
      assert_equal 6, cuboid6x6x3.height
      assert_equal 3, cuboid6x6x3.depth
    end
    
    def test_cuboid3x4x2
      assert_equal 3, cuboid3x4x2.width
      assert_equal 4, cuboid3x4x2.height
      assert_equal 2, cuboid3x4x2.depth
    end
    
    include AnalogLiterals::Helpers
 
    def rect2x3
      o-----o
      +     ~
      ~     ~
      ~     ~
      o-----o
    end
 
    def cuboid6x6x3
      o-------------o
      +L             \
      + L             \
      +  L             \
      +   o-------------o
      +   ~             ~
      ~   ~             ~
      o   +             ~
       L  +             ~
        L +             ~
         L+             ~
          o-------------o
    end
 
    def cuboid3x4x2
      o-------o
      +L       \
      + L       \
      +  o-------o
      +  ~       ~
      o  +       ~
       L +       ~
        L+       ~
         o-------o
    end
  end
end