The game of life is a simulation of cellular automaton. Each cell is arranged in a 2-D grid and has 8 neighboring cells. The life cycle of a cell is dictated by a simple set of rules.

• If a cell is alive and has fewer than 2 neighbors, it dies as if by loneliness.
• If a cell is alive and has more than 3 neighbors, it dies as if by starvation due to over-crowding.
• If a cell is alive and has 2 or 3 neighbors it remains alive.
• If a cell is dead and has exactly 3 neighbors it spawns, as if by reproduction.

A further description of the game of life can be found at Wikipedia.

I've written a short paper on the process I went through to optimize this program. I hope it helps out anyone looking to learn how to make Haskell software fast.

Requires GHC 7.6 and Haskell Platform 2013. Additional dependencies are listed in gameoflife.cabal.

• cabal install -j

Instructions for using the life program once installed.

The life program
  
life [OPTIONS]
  
Common flags:
  -w --width=INT      The number of cells across the game board.
  -h --height=INT     The number of cells tall.
  -c --cellwidth=INT  The number of pixels across a single cell.
  -g --genpersec=INT  The number of generations per second.
  -? --help           Display help message
  -V --version        Print version information

For example, if you wanted a game of life where the board was 100x100 and the 20 generations occurred every second, you would enter life -w 100 -h 100 -g 20 in the command line. The cell width modifier allows you to change the scale of each cell in pixels so that you can keep the whole game board on screen.