Switch to optparse-applicative for command line parsing

It supports parsing arguments and inserting custom strings into the help
message.

snorkels.cabal

@@ -64,7 +64,7 @@ executable snorkels
                        ansi-terminal >=0.6 && <0.7,
                        bimap >=0.3.2 && <0.3.3,
                        parsec >=3.1.11 && <3.1.12,
-                       options >=1.2.1.1 && <1.2.1.2
+                       optparse-applicative >=0.13.0 && <0.13.1
 
   -- Directories containing source files.
   hs-source-dirs:      src
@@ -96,7 +96,7 @@ library
                        ansi-terminal >=0.6 && <0.7,
                        bimap >=0.3.2 && <0.3.3,
                        parsec >=3.1.11 && <3.1.12,
-                       options >=1.2.1.1 && <1.2.1.2
+                       optparse-applicative >=0.13.0 && <0.13.1
 
   -- Directories containing source files.
   hs-source-dirs:      src

src/Main.hs

@@ -3,36 +3,58 @@ module Main where
 import qualified Data.Bimap as Bimap
 import Data.Function
 import qualified Data.Map.Strict as Map
+import Data.Monoid
 import System.Random (getStdGen)
 
-import Options
+import Options.Applicative
 
 import Snorkels.Types
 import Snorkels.Play
-import qualified Snorkels.CLI as CLI
+import Snorkels.CLI (cli)
+import Snorkels.RandomAgent (randomAgent)
 import qualified Snorkels.Board as B
 
 
-data MainOptions = MainOptions { optNumStones :: Int
-                               , optWidth :: Int
-                               , optHeight :: Int
-                               , optNumPlayers :: Int
-                               } deriving (Eq)
+data MainParser = MainParser { optNumStones :: Int
+                             , optWidth :: Int
+                             , optHeight :: Int
+                             , optNumPlayers :: Int
+                             } deriving (Eq)
 
 
-instance Options MainOptions where
-    defineOptions = pure MainOptions
-        <*> simpleOption "num-stones" 3
-            "Number of stones randomly thrown on the board"
-        <*> simpleOption "width" 7
-            "Width of the board"
-        <*> simpleOption "height" 7
-            "Height of the board"
-        <*> simpleOption "players" 2
-            "Number of players"
+mainParser :: Parser MainParser
+mainParser = MainParser
+        <$> option auto
+            ( long "stones"
+           <> short 's'
+           <> value 3
+           <> metavar "#STONES"
+           <> help "Number of stones randomly thrown on the board"
+            )
+        <*> option auto
+            ( long "width"
+           <> short 'w'
+           <> value 7
+           <> metavar "WIDTH"
+           <> help "Width of the board"
+            )
+        <*> option auto
+            ( long "height"
+           <> short 'h'
+           <> value 7
+           <> metavar "HEIGHT"
+           <> help "Height of the board"
+            )
+        <*> option auto
+            ( long "players"
+           <> short 'p'
+           <> value 2
+           <> metavar "#PLAYERS"
+           <> help "Number of players"
+            )
 
 
-create :: MainOptions -> IO (Either String Game)
+create :: MainParser -> IO (Either String Game)
 create options
     | max (options&optWidth) (options&optHeight) > 26 = return $ Left "Cannot have more than 26 on either axis."
     | otherwise = do g <- getStdGen
@@ -40,16 +62,25 @@ create options
     where players = take (optNumPlayers options) [Green ..]
           game = Game { pieces = Map.empty
                       , boardSize = (optWidth options, optHeight options)
-                      , playerTypes = Map.fromList [(p, CLI.cli) | p <- players]
+                      , playerTypes = Map.fromList [(Green, cli), (Purple, randomAgent)]
                       , currentPlayer = Green
                       , switches = Bimap.empty
                       }
 
 
+run :: MainParser -> IO ()
+run options = do game <- create options
+                 case game of
+                   Left message -> print message
+                   Right g -> do play g
+                                 return ()
+
+
 main :: IO ()
-main = runCommand $ \opts args -> do
-    game <- create opts
-    case game of
-      Left message -> print message
-      Right g -> do play g
-                    return ()
+main = execParser opts >>= run
+       where
+           opts = info (helper <*> mainParser)
+             ( fullDesc
+            <> progDesc "TODO"
+            <> header "Snorkels -- strategic board game")
+