initial exploration

.gitignore

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+*~
+dist-newstyle/
+TAGS

CHANGELOG.md

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+# Revision history for robot-exploration
+
+## 0.1.0.0 -- YYYY-mm-dd
+
+* First version. Released on an unsuspecting world.

app/Main.hs

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+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TemplateHaskell   #-}
+
+module Main where
+
+import           Control.Concurrent         (forkIO, threadDelay)
+import           Control.Lens
+import           Control.Lens.Unsound       (lensProduct)
+import           Control.Monad.State
+import           Data.Map                   (Map)
+import qualified Data.Map                   as M
+import           Data.Maybe
+import           Data.Set                   (Set)
+import qualified Data.Set                   as S
+import           Data.Void
+import           Linear
+
+import           Brick
+import           Brick.BChan
+import qualified Brick.Widgets.Border       as B
+import qualified Brick.Widgets.Border.Style as BS
+import qualified Brick.Widgets.Center       as C
+import qualified Graphics.Vty               as V
+
+import           Data.Text                  (Text)
+import           Text.Megaparsec            hiding (State)
+import           Text.Megaparsec.Char
+import qualified Text.Megaparsec.Char.Lexer as L
+
+------------------------------------------------------------
+-- AST
+
+data Command
+  = Wait
+  | Move
+  | TL
+  | TR
+  | Harvest
+  deriving (Eq, Ord, Show)
+
+type Program = [Command]
+
+------------------------------------------------------------
+-- Parsing
+------------------------------------------------------------
+
+type Parser = Parsec Void Text
+
+--------------------------------------------------
+-- Lexer
+
+sc :: Parser ()
+sc = L.space
+  space1
+  (L.skipLineComment "//")
+  (L.skipBlockComment "/*" "*/")
+
+lexeme :: Parser a -> Parser a
+lexeme = L.lexeme sc
+
+symbol :: Text -> Parser Text
+symbol = L.symbol sc
+
+reserved :: Text -> Parser ()
+reserved w = (lexeme . try) $ string' w *> notFollowedBy alphaNumChar
+
+--------------------------------------------------
+-- Parser
+
+parseCommand :: Parser Command
+parseCommand =
+      Move    <$ reserved "move"
+  <|> TL      <$ reserved "left"
+  <|> TR      <$ reserved "right"
+  <|> Harvest <$ reserved "harvest"
+
+parseProgram :: Parser Program
+parseProgram = many parseCommand
+
+------------------------------------------------------------
+-- State machine
+------------------------------------------------------------
+
+data Robot = Robot
+  { _location     :: V2 Int
+  , _direction    :: V2 Int
+  , _robotProgram :: Program
+  }
+  deriving (Eq, Ord, Show)
+
+data Item = Resource Char
+  deriving (Eq, Ord, Show)
+
+data GameState = GameState
+  { _baseProgram :: Program
+  , _robots      :: [Robot]
+  , _world       :: [[Char]]
+  , _inventory   :: Map Item Int
+  }
+  deriving (Eq, Ord, Show)
+
+makeLenses ''Robot
+makeLenses ''GameState
+
+step :: State GameState ()
+step = do
+  rs <- use robots
+  rs' <- catMaybes <$> forM rs stepRobot
+  robots .= rs'
+
+doStep :: GameState -> GameState
+doStep = execState step
+
+stepRobot :: Robot -> State GameState (Maybe Robot)
+stepRobot r = case r ^. robotProgram of
+  []        -> return Nothing
+  (cmd : p) -> Just <$> exec cmd (r & robotProgram .~ p)
+
+exec :: Command -> Robot -> State GameState Robot
+exec Wait    r = return r
+exec Move    r = return $ (r & location %~ (^+^ (r ^. direction)))
+exec TL      r = return $ (r & direction %~ vLeft)
+exec TR      r = return $ (r & direction %~ vRight)
+exec Harvest r = do
+  let V2 row col = r ^. location
+  mh <- preuse $ world . ix row . ix col
+  case mh of
+    Nothing -> return ()
+    Just h  -> do
+      world . ix row . ix col .= ' '
+      inventory . at (Resource h) . non 0 += 1
+  return r
+
+vLeft (V2 x y) = V2 (-y) (x)
+vRight (V2 x y) = V2 y (-x)
+
+------------------------------------------------------------
+-- UI
+
+data Tick = Tick
+
+type Name = ()
+
+app :: App GameState Tick Name
+app = App
+  { appDraw         = drawUI
+  , appChooseCursor = neverShowCursor
+  , appHandleEvent  = handleEvent
+  , appStartEvent   = return
+  , appAttrMap      = const theMap
+  }
+
+robotAttr :: AttrName
+robotAttr = "robotAttr"
+
+theMap :: AttrMap
+theMap = attrMap V.defAttr
+  [ (robotAttr, fg V.cyan `V.withStyle` V.bold)
+  ]
+
+handleEvent :: GameState -> BrickEvent Name Tick -> EventM Name (Next GameState)
+handleEvent g (AppEvent Tick)                       = continue $ doStep g
+handleEvent g (VtyEvent (V.EvKey (V.KChar 'q') [])) = halt g
+handleEvent g (VtyEvent (V.EvKey V.KEsc []))        = halt g
+handleEvent g _                                     = continue g
+
+drawUI :: GameState -> [Widget Name]
+drawUI g =
+  [ C.center $ drawWorld g <+> padLeft (Pad 2) (drawInventory (g ^. inventory))]
+
+drawWorld :: GameState -> Widget Name
+drawWorld g = withBorderStyle BS.unicode
+  $ B.border
+  $ padAll 1
+  $ vBox (imap (\r -> hBox . imap (\c x -> drawLoc r c x)) (g ^. world))
+  where
+    robotLocs = M.fromList $ g ^.. robots . traverse . lensProduct location direction
+    drawLoc r c x = case M.lookup (V2 r c) robotLocs of
+      Just dir -> withAttr robotAttr $ str (robotDir dir)
+      Nothing  -> str [x]
+
+robotDir (V2 0 1)    = "▶"
+robotDir (V2 0 (-1)) = "◀"
+robotDir (V2 1 0)    = "▼"
+robotDir (V2 (-1) 0) = "▲"
+
+drawInventory :: Map Item Int -> Widget Name
+drawInventory inv = withBorderStyle BS.unicode
+  $ B.borderWithLabel (str "Inventory")
+  $ padAll 1
+  $ vLimit 10
+  $ padBottom Max
+  $ vBox
+  $ map drawItem (M.assocs inv)
+
+drawItem :: (Item, Int) -> Widget Name
+drawItem (Resource c, n) = padRight (Pad 1) (str [c]) <+> showCount n
+  where
+    showCount = hLimit 7 . padLeft Max . str . show
+
+------------------------------------------------------------
+
+testGameState :: GameState
+testGameState = GameState [] [Robot (V2 0 0) (V2 0 1) testProgram] ["*.*$", "%**a"] M.empty
+
+testProgram :: Program
+testProgram = [Wait, Harvest, Move, Harvest, TR, Move, Harvest, TL, Move, Harvest, Harvest]
+
+main :: IO ()
+main = do
+  chan <- newBChan 10
+  forkIO $ forever $ do
+    writeBChan chan Tick
+    threadDelay 500000 -- decides how fast your game moves
+  let buildVty = V.mkVty V.defaultConfig
+  initialVty <- buildVty
+  void $ customMain initialVty buildVty (Just chan) app testGameState

robot-exploration.cabal

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+cabal-version:      2.4
+name:               robot-exploration
+version:            0.1.0.0
+
+-- A short (one-line) description of the package.
+-- synopsis:
+
+-- A longer description of the package.
+-- description:
+
+-- A URL where users can report bugs.
+-- bug-reports:
+
+-- The license under which the package is released.
+-- license:
+author:             Brent Yorgey
+maintainer:         byorgey@gmail.com
+
+-- A copyright notice.
+-- copyright:
+-- category:
+extra-source-files: CHANGELOG.md
+
+executable robot-exploration
+    main-is:          Main.hs
+
+    -- Modules included in this executable, other than Main.
+    -- other-modules:
+
+    -- LANGUAGE extensions used by modules in this package.
+    -- other-extensions:
+    build-depends:    base ^>=4.14.1.0, brick, vty, megaparsec, text, containers, linear, lens, mtl
+    hs-source-dirs:   app
+    default-language: Haskell2010
+    ghc-options:      -threaded