add exitpoints

Element.hs

@@ -3,22 +3,26 @@ module Element where
 data Element = Element { value :: Integer
                        , xPos  :: Int
                        , yPos  :: Int
+                       , state :: Bool
                        } deriving (Eq, Show)
 
 decVal :: Element -> Element
-decVal e = Element (value e - 1) (xPos e) (yPos e)
+decVal (Element v x y s) = Element (v - 1) x y s
 
 incVal :: Element -> Element
-incVal e = Element (value e + 1) (xPos e) (yPos e)
+incVal (Element v x y s) = Element (v + 1) x y s
 
 incXPos :: Element -> Element
-incXPos e = Element (value e) (xPos e + 1) (yPos e)
+incXPos (Element v x y s) = Element v (x + 1) y s
 
 decXPos :: Element -> Element
-decXPos e = Element (value e) (xPos e - 1) (yPos e)
+decXPos (Element v x y s) = Element v (x - 1) y s
 
 incYPos :: Element -> Element
-incYPos e = Element (value e) (xPos e) (yPos e + 1)
+incYPos (Element v x y s) = Element v x (y + 1) s
 
 decYPos :: Element -> Element
-decYPos e = Element (value e) (xPos e) (yPos e - 1)
+decYPos (Element v x y s) = Element v x (y - 1) s
+
+kill :: Element -> Element
+kill (Element v x y _) = Element v x y False

Main.hs

@@ -19,12 +19,19 @@ run :: String -> IO ()
 run inputFile = do
   input <- readFile inputFile
   let internalFactory = stringsToFactory $ lines input
-  interpretLoop internalFactory [uncurry (Element 0) $ entryPointLocation internalFactory]
+  let el = entryPointLocation internalFactory
+  interpretLoop internalFactory [Element 0 (fst el) (snd el) True]
 
 interpretLoop :: Factory -> [Element] -> IO ()
-interpretLoop f es = do
+interpretLoop f es =
+  let getDeadElement (e:es)
+        | state e == False = e
+        | otherwise = getDeadElement es
+  in do
   let elements = stepInterpret f es
-  printFactory f elements
+  if any (\e -> state e == False) es
+    then exitWith (ExitFailure $ fromInteger $ value $ getDeadElement es)
+    else printFactory f elements
   a <- getChar
   case a of
     'q' -> return ()
@@ -89,6 +96,7 @@ update f e = if oobCheck f e then error "Element out of bounds check failed!"
                       , (Special Duplicate,   dupFunc)
                       , (Special Conditional, singleton . zeroBranch)
                       , (Entrypoint,          singleton . spitOut East f)
+                      , (Exitpoint,           singleton . kill)
                       ]
         dupFunc :: Element -> [Element]
         dupFunc elem = [ spitOutNth 0 East f elem

Types.hs

@@ -34,6 +34,7 @@ data SpecialKind = Duplicate | Conditional
   deriving (Eq)
 
 data Tile = Entrypoint
+          | Exitpoint
           | Track Direction
           | Modifier ModifierKind
           | Special SpecialKind
@@ -49,6 +50,7 @@ type Factory = [[Tile]]
 charToTile :: Char -> Tile
 charToTile c = case c of
   'E' -> Entrypoint
+  'X' -> Exitpoint
   '>' -> Track East
   '<' -> Track West
   'v' -> Track South
@@ -62,6 +64,7 @@ charToTile c = case c of
 tileToChar :: Tile -> Char
 tileToChar t = case t of
   Entrypoint          -> 'E'
+  Exitpoint           -> 'X'
   Track East          -> '>'
   Track West          -> '<'
   Track South         -> 'v'

examples/exit.fac

@@ -0,0 +1 @@
+E>+>X