progress on challenge 2, reordered nextPos params

cw/src/Challenges.hs

@@ -7,7 +7,7 @@
 -- DO NOT MODIFY THE FOLLOWING LINES OF CODE
 module Challenges (WordSearchGrid,Placement,Posn,Orientation(..),solveWordSearch, createWordSearch,
     LamMacroExpr(..),LamExpr(..),prettyPrint, parseLamMacro,
-    cpsTransform,innerRedn1,outerRedn1,compareInnerOuter,generatePos) where
+    cpsTransform,innerRedn1,outerRedn1,compareInnerOuter) where
 
 -- Import standard library and parsing definitions from Hutton 2016, Chapter 13
 -- We import System.Random - make sure that your installation has it installed - use stack ghci and stack ghc
@@ -74,7 +74,7 @@ findPlacement css (x,y) s | checkWordDir css (x,y) Forward s           = Just ((
 checkWordDir :: WordSearchGrid -> (Int,Int) -> Orientation -> String -> Bool
 checkWordDir css (x,y) dir (l:[]) | nextElem css (x,y) dir == Just l   = True
                                   | otherwise                          = False
-checkWordDir css (x,y) dir (l:ls) | nextElem css (x,y) dir == Just l   = checkWordDir css (nextPos (x,y) dir) dir ls
+checkWordDir css (x,y) dir (l:ls) | nextElem css (x,y) dir == Just l   = checkWordDir css (nextPos dir (x,y)) dir ls
                                   | otherwise                          = False
 
 
@@ -82,15 +82,15 @@ checkWordDir css (x,y) dir (l:ls) | nextElem css (x,y) dir == Just l   = checkWo
 --------------------pattern matching for traversing the grid--------------------
 
 --returns position of movement in a given direction
-nextPos :: (Int,Int) -> Orientation -> (Int,Int)
-nextPos (x,y) Forward     = (x+1,y)
-nextPos (x,y) Back        = (x-1,y)
-nextPos (x,y) Up          = (x,y-1)
-nextPos (x,y) Down        = (x,y+1)
-nextPos (x,y) UpForward   = (x+1,y-1)
-nextPos (x,y) UpBack      = (x-1,y-1)
-nextPos (x,y) DownForward = (x+1,y+1)
-nextPos (x,y) DownBack    = (x-1,y+1)
+nextPos :: Orientation -> (Int,Int) -> (Int,Int)
+nextPos Forward     (x,y) = (x+1,y)
+nextPos Back        (x,y) = (x-1,y)
+nextPos Up          (x,y) = (x,y-1)
+nextPos Down        (x,y) = (x,y+1)
+nextPos UpForward   (x,y) = (x+1,y-1)
+nextPos UpBack      (x,y) = (x-1,y-1)
+nextPos DownForward (x,y) = (x+1,y+1)
+nextPos DownBack    (x,y) = (x-1,y+1)
 
 
 elemAt :: [[a]] -> (Int,Int) -> a
@@ -102,7 +102,7 @@ nextElem :: [[a]] -> (Int,Int) -> Orientation -> Maybe a
 nextElem css (x,y) dir | x' < 0 || y' < 0 || x' > length css - 1 || y' > length css - 1 = Nothing
                        | otherwise                                                      = Just (elemAt css (x',y'))
     where
-      (x',y') = nextPos (x,y) dir
+      (x',y') = nextPos dir (x,y)
 
 
 -- Two examples for you to try out, the first of which is in the instructions
@@ -126,8 +126,7 @@ createWordSearch ss den = do gen <- getStdGen
     where
       charInInput    = sum (map length ss)
       longestWordLen = max (map length ss)
-      dim            = head [x | x <- [0..], x^2 > (charInInput / den), x >= longestWordLen]   --calculates needed dimension of grid according
-                                                                                               --to the density
+      dim            = head [x | x <- [0..], x^2 > (charInInput / den), x >= longestWordLen]   --calculates needed dimension of grid according to the density
 
 
 createGrid :: [String] -> Int -> StdGen -> WordSearchGrid
@@ -159,13 +158,19 @@ checkDir rg s (x,y) dir =
 --adds an individual string to a given grid
 --returns new grid and new generator
 insertString :: RandGrid -> String -> StdGen -> (RandGrid,StdGen)
-insertString rg s gen | 
-                      | length vDirs == 0 = insertString rg s newGen
-                      | 
+insertString rg s gen | elemAt rg (x,y) /= Rand &&
+                        elemAt rg (x,y) /= Letter (head s) = insertString rg s newGen        --guard:if position is invalid, generate new position
+                      | length vDirs == 0                  = insertString rg s newGen        --guard:if no valid orientations exist, generate new position
+                      | otherwise                           
     where
       ((x,y),newGen) = generatePos gen (length rg)
       vDirs = validDirs rg s (x,y)
 
+      addToGrid :: String -> Orientation -> RandGrid
+      addToGrid s dir = iterate 
+      --iterate to get positions
+      --zip together with string
+      --map to add to grid
 
 
 generatePos :: StdGen -> Int -> ((Int,Int),StdGen)