TicTacToe
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| - | + | [[Category:Code]] | |
| + | == Diary of a Tic-tac-toe program == | ||
| + | 1/27/2007 | ||
<haskell> | <haskell> | ||
module TicTacToe | module TicTacToe | ||
| Line 15: | Line 17: | ||
firstFree (x:xs) | x == ' ' = 1 | firstFree (x:xs) | x == ' ' = 1 | ||
| otherwise = 1 + (firstFree xs) | | otherwise = 1 + (firstFree xs) | ||
| + | |||
main = do | main = do | ||
putStrLn "Enter your move:" | putStrLn "Enter your move:" | ||
| - | + | move1Num <- readLn | |
| - | + | ||
let board1 = place " " move1Num 'X' | let board1 = place " " move1Num 'X' | ||
let board2 = place board1 (firstFree board1) 'O' | let board2 = place board1 (firstFree board1) 'O' | ||
| Line 24: | Line 26: | ||
putStrLn "Enter your move:" | putStrLn "Enter your move:" | ||
| - | + | move2Num <- readLn | |
| - | + | ||
let board3 = place board2 move2Num 'X' | let board3 = place board2 move2Num 'X' | ||
let board4 = place board3 (firstFree board3) 'O' | let board4 = place board3 (firstFree board3) 'O' | ||
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putStrLn "Enter your move:" | putStrLn "Enter your move:" | ||
| - | + | move3Num <- readLn | |
| - | + | ||
let board5 = place board4 move3Num 'X' | let board5 = place board4 move3Num 'X' | ||
let board6 = place board5 (firstFree board5) 'O' | let board6 = place board5 (firstFree board5) 'O' | ||
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putStrLn "Enter your move:" | putStrLn "Enter your move:" | ||
| - | + | move4Num <- readLn | |
| - | + | ||
let board7 = place board6 move4Num 'X' | let board7 = place board6 move4Num 'X' | ||
let board8 = place board7 (firstFree board7) 'O' | let board8 = place board7 (firstFree board7) 'O' | ||
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putStrLn "Enter your move:" | putStrLn "Enter your move:" | ||
| - | + | move5Num <- readLn | |
| - | + | ||
let board9 = place board8 move5Num 'X' | let board9 = place board8 move5Num 'X' | ||
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* computer vs. computer mode | * computer vs. computer mode | ||
* genetically-evolved players | * genetically-evolved players | ||
| + | |||
| + | 1/29/2007 | ||
| + | Well, the TicTacToe project is now two days old, and it's time to check in on its growth. Here's the newest snapshot of its code: | ||
| + | |||
| + | <haskell> | ||
| + | module TicTacToe | ||
| + | where | ||
| + | |||
| + | import Control.Monad.State | ||
| + | |||
| + | main = runStateT code " " >> return () | ||
| + | |||
| + | code :: StateT String IO () | ||
| + | code = do | ||
| + | m1 <- lift readLn | ||
| + | modify (place m1 'X') | ||
| + | modify (makeMove) | ||
| + | |||
| + | m2 <- lift readLn | ||
| + | modify (place m2 'X') | ||
| + | modify (makeMove) | ||
| + | |||
| + | m3 <- lift readLn | ||
| + | modify (place m3 'X') | ||
| + | modify (makeMove) | ||
| + | |||
| + | m4 <- lift readLn | ||
| + | modify (place m4 'X') | ||
| + | modify (makeMove) | ||
| + | |||
| + | m5 <- lift readLn | ||
| + | modify (place m5 'X') | ||
| + | |||
| + | y <- get | ||
| + | liftIO $ print y | ||
| + | return () | ||
| + | |||
| + | place :: Int -> Char -> String -> String | ||
| + | place _ _ [] = [] | ||
| + | place 1 c (x:xs) = c : xs | ||
| + | place n c (x:xs) = x : (place (n-1) c xs) | ||
| + | |||
| + | findFree :: String -> Int | ||
| + | findFree (x:xs) | x == ' ' = 1 | ||
| + | | otherwise = 1 + findFree xs | ||
| + | |||
| + | makeMove :: String -> String | ||
| + | makeMove = flip place 'O' =<< findFree | ||
| + | </haskell> | ||
| + | |||
| + | Well, perhaps 'growth' isn't quite the correct term, since the code has actually shrunk by several lines. Nor has it 'grown' in the features it has, yet. What has happened is that we've used the State monad to get rid of the numerous boards threaded through main. Now there's a single board (which makes good logical sense), which we can access and modify using get, put, and modify. It's still as dumb as a rock, but at least it's a little cleaner! | ||
Current revision
Diary of a Tic-tac-toe program
1/27/2007
module TicTacToe where data Board = String place :: String -> Int -> Char -> String place [] _ _ = [] place (x:xs) 1 c = c : xs place (x:xs) n c = x : (place xs (n-1) c) firstFree :: String -> Int firstFree (x:xs) | x == ' ' = 1 | otherwise = 1 + (firstFree xs) main = do putStrLn "Enter your move:" move1Num <- readLn let board1 = place " " move1Num 'X' let board2 = place board1 (firstFree board1) 'O' putStrLn ("New board:" ++ board2) putStrLn "Enter your move:" move2Num <- readLn let board3 = place board2 move2Num 'X' let board4 = place board3 (firstFree board3) 'O' putStrLn ("New board:" ++ board4) putStrLn "Enter your move:" move3Num <- readLn let board5 = place board4 move3Num 'X' let board6 = place board5 (firstFree board5) 'O' putStrLn ("New board:" ++ board6) putStrLn "Enter your move:" move4Num <- readLn let board7 = place board6 move4Num 'X' let board8 = place board7 (firstFree board7) 'O' putStrLn ("New board:" ++ board8) putStrLn "Enter your move:" move5Num <- readLn let board9 = place board8 move5Num 'X' putStrLn ("Final board:" ++ board9)
Hideous, isn't it? Why, thank you! That is, in fact, the point. I want to start with an absolutely hideous piece of code, and add features, re-factoring as I go. It seems to me like there's actually a lot you can do with tic-tac-toe, and so I hope this will turn into something instructive, both for me and for anyone who wants to follow along, and/or contribute.
Feature ideas (in no particular order):
- output a real board
- game-end condition check
- curses-based interface
- tic-tac-toe variants
- computer can be x or o
- two-player mode
- tournament mode
- web interface
- lazy alpha-beta player
- random square player
- brute-force player
- computer vs. computer mode
- genetically-evolved players
1/29/2007 Well, the TicTacToe project is now two days old, and it's time to check in on its growth. Here's the newest snapshot of its code:
module TicTacToe where import Control.Monad.State main = runStateT code " " >> return () code :: StateT String IO () code = do m1 <- lift readLn modify (place m1 'X') modify (makeMove) m2 <- lift readLn modify (place m2 'X') modify (makeMove) m3 <- lift readLn modify (place m3 'X') modify (makeMove) m4 <- lift readLn modify (place m4 'X') modify (makeMove) m5 <- lift readLn modify (place m5 'X') y <- get liftIO $ print y return () place :: Int -> Char -> String -> String place _ _ [] = [] place 1 c (x:xs) = c : xs place n c (x:xs) = x : (place (n-1) c xs) findFree :: String -> Int findFree (x:xs) | x == ' ' = 1 | otherwise = 1 + findFree xs makeMove :: String -> String makeMove = flip place 'O' =<< findFree
Well, perhaps 'growth' isn't quite the correct term, since the code has actually shrunk by several lines. Nor has it 'grown' in the features it has, yet. What has happened is that we've used the State monad to get rid of the numerous boards threaded through main. Now there's a single board (which makes good logical sense), which we can access and modify using get, put, and modify. It's still as dumb as a rock, but at least it's a little cleaner!
