3 files changed, 22 insertions(+), 8 deletions(-)

M .nix/maze-escape.nix
M lib/Game/Maze.hs
M maze-escape.cabal

@@ 1,10 1,10 @@
-{ mkDerivation, base, hspec, ilist, lib, mtl, utility-ht }:
+{ mkDerivation, base, hspec, ilist, lib, mtl, utility-ht, containers }:
 mkDerivation {
   pname = "maze-escape";
   version = "0.1.0.0";
   src = ../.;
-  libraryHaskellDepends = [ base ilist mtl utility-ht ];
-  testHaskellDepends = [ base hspec ilist mtl utility-ht ];
+  libraryHaskellDepends = [ base ilist mtl utility-ht containers ];
+  testHaskellDepends = [ base hspec ilist mtl utility-ht containers ];
   homepage = "https://gitlab.com/Vonfry/maze-escape";
   license = lib.licenses.gpl3Plus;
 }

@@ 5,11 5,14 @@ module Game.Maze (MovableCell(..), Maze2D(..)) where
 import Data.Function (on)
 import Data.Foldable (minimumBy)
 import Data.Ord (comparing)
+import Data.Map (Map(..), empty)
+import Control.Monad.State
+import Control.Monad.Reader
 
 class MovableCell cell where
   movable :: cell -> Bool
 
-class Maze2D map pos cell where
+class Eq pos => Maze2D map pos cell where
   adjacence :: map pos cell -> pos -> [pos]
 
   source :: map pos cell -> [pos]


@@ 19,8 22,18 @@ class Maze2D map pos cell where
   getCell :: map pos cell -> pos -> cell
 
   shortestEscapePath :: map pos cell -> [pos]
-  shortestEscapePath = filterMinLength . fmap bfs . source
+  shortestEscapePath = flip evalState empty . runBfs
     where
-      filterMinLength = minimumBy $ comparing length
-      -- TODO
-      bfs _ = []
+      runBfs = runReaderT =<< bfs . source
+      bfs :: [pos] -> RMapEscape map pos
+      bfs _ = pure []
+
+data MapEscapeMark pos =
+  MapEscapeMark { marked :: Bool
+                , toDest :: [pos]
+                }
+type RMapEscapeState pos = State (Map pos (MapEscapeMark pos))
+type RMapEscape map pos = ReaderT map (RMapEscapeState pos) [pos]
+
+filterMinLength :: [[pos]] -> [pos]
+filterMinLength = minimumBy $ comparing length

@@ 23,6 23,7 @@ common deps
                     , mtl
                     , ilist
                     , utility-ht
+                    , containers
 
 library
     import:           deps