Refactor wall points from lists to pairs

src/Dodge/Base.hs

@@ -63,26 +63,26 @@ yourItemRef w = (creatures . ix (_yourID w) . crInv . ix (_crInvSel (you w)))
 wallNormal :: Wall -> Point2
 wallNormal wl = normalizeV . vNormal $ a -.- b
   where 
-    (a:b:_) = _wlLine wl
+    (a,b) = _wlLine wl
 
 wallsOnLine :: Point2 -> Point2 -> IM.IntMap Wall -> [Wall]
 wallsOnLine p1 p2 ws = hitWalls
   where 
-    hitPoint w = intersectSegSeg' p1 p2 (_wlLine w !! 0) (_wlLine w !! 1)
+    hitPoint w = intersectSegSeg' p1 p2 (fst $ _wlLine w) (snd $ _wlLine w)
     hitWalls = filter (isJust . hitPoint) (IM.elems ws)
 
 wallOnLine :: Point2 -> Point2 -> IM.IntMap Wall -> Maybe Wall
 wallOnLine p1 p2 ws 
     = listToMaybe $ sortBy f hitWalls
   where 
-    hitPoint w = intersectSegSeg' p1 p2 (_wlLine w !! 0) (_wlLine w !! 1)
+    hitPoint w = intersectSegSeg' p1 p2 (fst $ _wlLine w) (snd $ _wlLine w)
     hitWalls = filter (isJust . hitPoint) (IM.elems ws)
     f w1 w2 = compare (magV (p1 -.- fromJust (hitPoint w1))) (magV (p1 -.- fromJust (hitPoint w2)))
 
 wallsOnCirc :: Point2 -> Float -> IM.IntMap Wall -> [Wall]
 wallsOnCirc p r wls = IM.elems $ IM.filter f wls
   where 
-    f wl = circOnSeg (_wlLine wl !! 0) (_wlLine wl !! 1) p r
+    f wl = circOnSeg (fst $ _wlLine wl) (snd $ _wlLine wl) p r
 
 
 allWalls :: World -> IM.IntMap Wall
@@ -267,7 +267,7 @@ collideCircWalls' p1 p2 rad ws
         ) ws
   where 
     f (a,_) = magV (p1 -.- a)
-    shiftByRad (a:b:_) = map ((rad *.* normalizeV (vNormal $ a -.- b)) +.+)
+    shiftByRad (a,b) = map ((rad *.* normalizeV (vNormal $ a -.- b)) +.+)
         [a +.+ rad *.* normalizeV (a -.-b)
         ,b +.+ rad *.* normalizeV (b -.-a)
         ]
@@ -284,7 +284,7 @@ collidePointWallsNorm p1 p2 ws
     = listToMaybe 
     . sortOn f 
     . IM.elems 
-    $ IM.mapMaybe (( \(x:y:_) -> intersectSegSeg' p1 p2 x y <&> (, vNormal $ x -.- y ) ) 
+    $ IM.mapMaybe (( \(x,y) -> intersectSegSeg' p1 p2 x y <&> (, vNormal $ x -.- y ) ) 
         . _wlLine) ws
   where 
     f (a,_) = magV (p1 -.- a)
@@ -297,7 +297,7 @@ collidePointWallsCol p1 p2 ws
     . sortOn f 
     . IM.elems 
     $ IM.mapMaybe ( (\(m, c) -> m <&> (, c))
-        . (\w -> (intersectSegSeg' p1 p2 (_wlLine w !! 0) (_wlLine w !! 1), _wlColor w))) ws
+        . (\w -> (intersectSegSeg' p1 p2 (fst $ _wlLine w) (snd $ _wlLine w), _wlColor w))) ws
   where 
     f (a,_) = magV (p1 -.- a)
 {- | Looks for first collision of a point with walls.
@@ -312,7 +312,7 @@ collidePointWallsNormCol p1 p2 ws
   where 
     f (a,_,_) = magV $ p1 -.- a
     m w = 
-        let (x:y:_) = _wlLine w
+        let (x,y) = _wlLine w
         in intersectSegSeg' p1 p2 x y <&> (, vNormal (x -.- y), _wlColor w)
 -- | Returns the first creature, if any, that a point intersects with.
 collidePointCreatures :: Point2 -> Point2 -> World -> Maybe Int
@@ -372,7 +372,7 @@ collidePointCrsWithoutPoint cid p1 p2 w
 {- | Test if a circle collides with any wall. -}
 circOnSomeWall :: Point2 -> Float -> World -> Bool
 circOnSomeWall p rad w 
-    = any (\(x:y:_) -> circOnSeg x y p rad) 
+    = any (\(x,y) -> circOnSeg x y p rad) 
     . fmap _wlLine 
     . IM.elems 
     $ wallsNearPoint p w