made some stylistic changes

approximate.hs

@@ -10,29 +10,31 @@ import Data.Char
 
 frequencyMap [] ngmap = ngmap
 frequencyMap ((_, 0.0):ngs) ngmap = frequencyMap ngs ngmap
-frequencyMap ((ng, p):ngs) ngmap = case Dm.lookup (DB.head ng) ngmap of
-                                Nothing -> frequencyMap ngs (Dm.insert (DB.head ng) [(ng, p)] ngmap)
-                                Just xs -> frequencyMap ngs (Dm.insert (DB.head ng) ((ng, p) : xs) ngmap)
+frequencyMap ((ng, p):ngs) ngmap = 
+  case Dm.lookup (DB.head ng) ngmap of
+      Nothing -> frequencyMap ngs (Dm.insert (DB.head ng) [(ng, p)] ngmap)
+      Just xs -> frequencyMap ngs (Dm.insert (DB.head ng) ((ng, p) : xs) ngmap)
 
-nextChoice k xs = case k of
-                    1 -> DB.pack [DB.head xs]
-                    _ -> DB.take (k-1) xs
+nextChoice 1 xs = DB.pack [DB.head xs]
+nextChoice _ xs = DB.take (k-1) xs
 
+generateText k n acc cur freqmap = 
+  do
+    let (Just probabilities) = Dm.lookup cur freqmap
+    choice <- MR.fromList probabilities
+    let next = DB.last choice
+    case n of 
+      0 -> return acc
+      _ -> generateText k (n-1) (DB.append acc (nextChoice k choice)) next freqmap
 
-generateText k n acc cur freqmap = do
-                        let (Just probabilities) = Dm.lookup cur freqmap
-                        choice <- MR.fromList probabilities
-                        let next = DB.last choice
-                        case n of 
-                            0 -> return acc
-                            _ -> generateText k (n-1) (DB.append acc (nextChoice k choice)) next freqmap
+gibberish n = 
+  do
+    js <- (DB.readFile "./quadgrams.json")
+    let (Just ngramPairs) = decode js :: Maybe (Dm.Map DB.ByteString Rational)
+    result <- generateText 4 n "" 116 (frequencyMap (Dm.toList ngramPairs) (Dm.singleton 0 []))
+    return result
 
-gibberish n = do
-        js <- (DB.readFile "./quadgrams.json")
-        let (Just ngramPairs) = decode js :: Maybe (Dm.Map DB.ByteString Rational)
-        result <- generateText 4 n "" 116 (frequencyMap (Dm.toList ngramPairs) (Dm.singleton 0 []))
-        return result
-
-main = do
-        output <- gibberish 1550
-        DB.writeFile "./output3.txt" output
+main = 
+  do
+    output <- gibberish 1550
+    DB.writeFile "./output3.txt" output