docs: comment helper functions

Proj2.hs

@@ -162,12 +162,25 @@ nextGuess (prevGuess, chord : chords) _ = (chord, chords)
 
 -- ==== HELPER FUNCTIONS ======================================================
 
+-- given lists xs and ys, calculates the maximum number of pairwise matches
+-- between xs and all permutations of ys
+--
+-- used in the feedback function to calculate the number of correct notes
+-- and/or octaves
+--
 matches :: (Eq a, Show a) => [a] -> [a] -> Int
 matches xs ys = maximum permutationMatches
   where
     permutationMatches = map (pairwiseMatches xs) (permutations ys)
     pairwiseMatches xs ys = length $ filter (uncurry (==)) $ zip xs ys
 
+-- outputs a list of all possible chords, where a chord is a list of unique
+-- pitches. this function happens to generate chords such that the pitches are
+-- in alphabetical order, but this is only to ensure that there are no
+-- duplicate pitches
+--
+-- used in initialGuess as the game state (represents all possible targets)
+--
 allChords :: [[Pitch]]
 allChords =
   [ chord