From: Dave Burt <dave@...>
Date: 2006-05-16T01:24:06+09:00
Subject: Re: Conway's Life de-golfed

Mike Nelson wrote:
> I took some golfed code from a discussion here little while back ( 
> http://www.ruby-forum.com/search?query=Golfing+a+signature.&forums%5B%5D=4 
> ) and tried my hand at de-golfing and re-working it a bit to make it 
> readable.

What version did you deobfuscate?

I have here the version on J`ey's site, and then a three-line version of
mine.

I used these clarification methods:
* add whitespace
* add comments
* rename variables
* translate conditional tri-graphs (foo?bar:baz) to if blocks

Cheers,
Dave

> #############################################################################
> # http://en.wikipedia.org/wiki/Conway%27s_Game_of_Life                      #
> # joey@eachmapinject.com                                                    #
> # j`ey (with thanks to Florian Gross and Dave Burt)                         #
> # 305 characters                                                            #
> #############################################################################
> s,o,f,c,u=20,"#"," ";b=(z=0..s).map{z.map{(rand<0.3)?o:f}};$><<"\e[2J";until
> c==b;$><<"\e[H"<<b.map{|x|x*" "}*"\n";c=b.map{|z|z.dup};s.times{|i|s.times{|
> e|n=(q,z=-1..1,[];q.map{|x|q.map{|y|z<<[x,y]}};(z-=[[0,0]]).map{|x|c[i+x[0]][
> e+x[1]]rescue u}-[f,u]).size;b[i][e]=(n==2?b[i][e]:n==3?o:f)}};sleep 0.2;end

size,  occupied, forsaken, combat_area_last_turn,  undefined =
  20,  "#",      " "       # nil,                  nil

battlefield = (z = 0..size).map {
  z.map {
    if rand < 0.3
      occupied
    else
      forsaken
    end
  }
}

$> << "\e[2J"

until combat_area_last_turn == battlefield

  $> << "\e[H" <<
        battlefield.map {|x| x * " " } * "\n"

  combat_area_last_turn = battlefield.map {|z| z.dup }

  # iterate over the entire grid
  size.times {|i|
    size.times {|e|

      neighbour_count =
        (q, z = -1..1, []
         q.map {|x| q.map {|y| z << [x, y] } }

         # x iterates over the set of 8 relative neighbour coordinates
         (z -= [[0, 0]]).map {|x|

           # return the neighbour's value from last turn
           combat_area_last_turn[i + x[0]][e + x[1]] rescue undefined

         } - [forsaken, undefined]  # don't count empties or off-the-edges
        ).size

      # update the cell based on last turn's neighbour count
      battlefield[i][e] =
        if neighbour_count == 2
          battlefield[i][e]
        else
          if neighbour_count == 3
            occupied
          else
            forsaken
          end
        end
    }
  }
  sleep 0.2
end



# And my version. You will need to hit Ctrl+Break to stop it.
o,f,m,c="#"," ",[-1,0,1]*3;b=([7]*20).map{(0..20).map{(rand<0.3)?o:f}};loop{
$><<b.map{|x|x*f+"\n"};c=b.map{|x|x.dup};20.times{|i|20.times{|e|n=(m.sort.zip(
m)-[[0,0]]).select{|x,y|o==(c[i+x]||[])[e+y]}.size;n!=2?b[i][e]=n==3?o:f:9}}}


# And the same thing with a little whitespace.
o = "#"
f = " "
c = nil    # copy of b
# b        # main grid
m = [-1, 0, 1] * 3

b = ([7] * 20).map { (0..20).map { (rand < 0.3) ? o : f } }

loop {
  $> << b.map {|x| x * f + "\n" }
  c = b.map {|x| x.dup }
  20.times {|i|
    20.times {|e|
      n =
        (m.sort.zip(m) - [[0, 0]]).select {|x, y|
          o == (c[i + x] || [])[e + y]
        }.size
      n != 2 ? b[i][e] = n == 3 ? o :
                                  f :
               9
    }
  }
  #sleep 0.1
}