refactor: inline functions in feedback for clarity

Proj2.hs

@@ -130,26 +130,23 @@ toPitch _ = Nothing
 -- performer to decide on the best guess to make each turn
 --
 feedback :: [Pitch] -> [Pitch] -> (Int, Int, Int)
-feedback target guess = (length correctPitches, correctNotes, correctOctaves)
+feedback target guess = (pitches, notes, octaves)
   where
     -- since pitches are unique in a guess,
     -- we can use set math to count how many are correct
     targetSet = S.fromList target
     guessSet = S.fromList guess
 
-    correctPitches = S.intersection targetSet guessSet
-
-    newTarget = S.toList $ S.difference targetSet correctPitches
-    newGuess = S.toList $ S.difference guessSet correctPitches
-
-    (targetNotes, guessNotes) = (map note newTarget, map note newGuess)
-    (targetOctaves, guessOctaves) = (map octave newTarget, map octave newGuess)
+    pitchSet = S.intersection targetSet guessSet
+    pitches = length pitchSet
 
     -- since notes and octaves are not unique in a guess,
     -- we can compare the guess to all possible permutations of the target
     -- and count the pairwise note/octave matches
-    correctNotes = matches targetNotes guessNotes
-    correctOctaves = matches targetOctaves guessOctaves
+    targetNoPitches = S.toList $ S.difference targetSet pitchSet
+    guessNoPitches = S.toList $ S.difference guessSet pitchSet
+    notes = matches (map note targetNoPitches) (map note guessNoPitches)
+    octaves = matches (map octave targetNoPitches) (map octave guessNoPitches)
 
 -- TODO: comment me
 --