haskell-tutorial

Me learning haskell, so bear this in mind if reviewing code. Code will evolve as learning curve is scaled.

TicTac/*.hs

Primitive Tic-Tac-Toe (Naughts & Crosses), playable from ghci prompt.

There are four ways to play it. All play functions share common behaviour:

• Return the updated board - capture this to perform successive plays

• Use newBoard to get an unplayed board

• Board location range is a value from 1-9, expressed in row major order

• If location supplied to function is out of range, computer will make next move

• If location supplied is already marked, board remains unchanged

• Strategy is a Board -> Board function

• Board is a Data.List of Square

• Square has:

  • location
  • tic (the Player who ticked it, N if unticked
  • move an Int == move sequence in play (0 if unticked)

• There are three pre-defined strategies:

  • smartMove: easily defeated (so not very smart after all)
  • smarterMove: also defeatable, but somewhat less easily
  • cleverMove: probably undefeatable (there's a strategyChecker in TicTac.Test which says it is, but I've not proved the checker to be complete)

• Of course strategy is used only when the computer is playing

Basic play:

play Board location - make next move using supplied board and at requested Location - (employs the cleverMove strategy if computer moves)

Test play (in TicTacTest.hs):

For these functions, board location expressed using the underlying Location representation of (Row,Column), where Row is T, M, or B; Column is L, R, or C

1. playUsing Strategy Board Location - make next move at requested location - (employs the specified strategy if computer moves)
2. playARoundUsing Strategy Board Location - make next move at requested location using suppled strategy, then make next move automatically

Note: if the playARound functions are invoked supplying an already used Location, the behaviour will be the same as play supplying an out-of-range Location - this is becasue the 1st play will do nothing, then the computer will play - in effect playing for you.

There are also some auto-play functions:

1. autoPlayUsing Board - computer plays the supplied board until there's a winner or a draw using the supplied strategy
2. autoPlayFromUsing Location - computer starts a new board, plays the requested Location, then carries on like autoPlayUsing