changed nextLetter to nextElem + added test

cw/src/Challenges.hs

@@ -69,9 +69,9 @@ findPlacement css x y s | checkWordDir css (x,y) Forward s           = Just ((x,
                         | otherwise                                  = Nothing
 
 checkWordDir :: WordSearchGrid -> (Int,Int) -> Orientation -> String -> Bool
-checkWordDir css (x,y) dir (l:[]) | nextLetter css x y dir == Just l = True
+checkWordDir css (x,y) dir (l:[]) | nextElem css x y dir == Just l   = True
                                   | otherwise                        = False
-checkWordDir css (x,y) dir (l:ls) | nextLetter 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 (x,y) dir) dir ls
                                   | otherwise                        = False
 
 
@@ -88,26 +88,9 @@ nextPos (x,y) UpBack      = (x-1,y-1)
 nextPos (x,y) DownForward = (x+1,y+1)
 nextPos (x,y) DownBack    = (x-1,y+1)
 
---returns element 
-nextLetter :: WordSearchGrid -> Int -> Int -> Orientation -> Maybe Char
--- nextLetter css x y Forward     | x == length css - 1                        = Nothing
---                                | otherwise                                  = Just ((css !! y) !! (x + 1))
--- nextLetter css x y Back        | x == 0                                     = Nothing
---                                | otherwise                                  = Just ((css !! y) !! (x - 1))
--- nextLetter css x y Up          | y == 0                                     = Nothing
---                                | otherwise                                  = Just ((css !! (y - 1)) !! x)
--- nextLetter css x y Down        | y == length css - 1                        = Nothing
---                                | otherwise                                  = Just ((css !! (y + 1)) !! x)
--- nextLetter css x y UpForward   | y == 0 || x == length css - 1              = Nothing
---                                | otherwise                                  = Just ((css !! (y - 1)) !! (x + 1))
--- nextLetter css x y UpBack      | y == 0 || x == 0                           = Nothing
---                                | otherwise                                  = Just ((css !! (y - 1)) !! (x - 1))
--- nextLetter css x y DownForward | y == length css - 1 || x == length css - 1 = Nothing
---                                | otherwise                                  = Just ((css !! (y + 1)) !! (x + 1))
--- nextLetter css x y DownBack    | y == length css - 1 || x == 0              = Nothing
---                                | otherwise                                  = Just ((css !! (y + 1)) !! (x - 1))
-
-nextLetter css x y dir | x' < 0 || y' < 0 || x' > length css - 1 || y' > length css - 1 = Nothing
+--returns specified adjacent element in grid, relative to given position 
+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 ((css !! y') !! x')
     where
       (x',y') = nextPos (x,y) dir

cw/test/Spec.hs

@@ -6,16 +6,14 @@ main = challenge1Test
 
 exGrid1'1  = [ "HAGNIRTSH" , "SACAGETAK", "GCSTACKEL","MGHKMILKI","EKNLETGCN","TNIRTLETE","IRAAHCLSR","MAMROSAGD","GIZKDDNRG" ]
 exWords1'1 = [ "HASKELL","STRING","STACK","MAIN","METHOD"]
--- exAns1'1   = [("HASKELL",Just((0,0),DownForward)),("STRING",Just((7,0),Back)),("STACK",Just((2,2),Forward)),
---               ("MAIN",   Just((2,7),Up         )),("METHOD",Just((4,3),Down))]
-exAns1'1   = [("HASKELL",Just((0,0),DownForward)),("STRING",Just((7,0),Back)),("STACK",Just((2,2),Forward)),("MAIN",Just((2,7),Up)),("METHOD",Just((4,3),Down))]
+exAns1'1   = [("HASKELL",Just((0,0),DownForward)),("STRING",Just((7,0),Back)),("STACK",Just((2,2),Forward)),
+              ("MAIN",   Just((2,7),Up         )),("METHOD",Just((4,3),Down))]
 
 exGrid1'2  = ["ROBREUMBR","AURPEPSAN","UNLALMSEE","YGAUNPYYP","NLMNBGENA","NBLEALEOR","ALRYPBBLG","NREPBEBEP","YGAYAROMR"]
 exWords1'2 = [ "BANANA", "ORANGE", "MELON", "RASPBERRY","APPLE","PLUM","GRAPE" ]
--- exAns1'2   = [("BANANA",   Just((5,6),UpBack  )),("ORANGE",Just((1,0),DownForward)),("MELON",Just((7,8),Up      )),
---               ("RASPBERRY",Just((8,0),DownBack)),("APPLE", Just((2,8),UpForward  )),("PLUM", Just((5,1),DownBack)),
---               ("GRAPE",    Just((8,6),Up      ))]
---exAns1'2   = [("BANANA",Just((5,6),UpBack)),("ORANGE",Just((1,0),DownForward)),("MELON",Just((7,8),Up)),("RASPBERRY",Just((8,0),DownBack)),("APPLE", Just((2,8),UpForward)),("PLUM", Just((5,1),DownBack)),("GRAPE",Just((8,6),Up))]
+exAns1'2   = [("BANANA",   Just((5,6),UpBack  )),("ORANGE",Just((1,0),DownForward)),("MELON",Just((7,8),Up      )),
+              ("RASPBERRY",Just((8,0),DownBack)),("APPLE", Just((2,8),UpForward  )),("PLUM", Just((5,1),DownBack)),
+              ("GRAPE",    Just((8,6),Up      ))]
 
 exGrid1'3  = ["TEST","ASBD","GDFI","FDGS"]
 exWords1'3 = ["TEST"]
@@ -38,6 +36,6 @@ challenge1Test = do putStrLn "Challenge 1 Start Test"
                     putStrLn "========================================="
                     assert1 (solveWordSearch exWords1'3 exGrid1'3) exAns1'3
                     assert1 (solveWordSearch exWords1'1 exGrid1'1) exAns1'1
-                    --assert1 (solveWordSearch exWords1'2 exGrid1'2) exAns1'2
+                    assert1 (solveWordSearch exWords1'2 exGrid1'2) exAns1'2
                     putStrLn "========================================="
                     putStrLn "Challenge 1 End Test"
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