dependency bump & fourmolu

.gitignore

@@ -3,3 +3,5 @@
 /.direnv/
 **/.DS_Store
 /cabal.project.local
+/compress.hp
+/*.prof

flake.lock

@@ -5,11 +5,11 @@
         "nixpkgs-lib": "nixpkgs-lib"
       },
       "locked": {
-        "lastModified": 1709336216,
-        "narHash": "sha256-Dt/wOWeW6Sqm11Yh+2+t0dfEWxoMxGBvv3JpIocFl9E=",
+        "lastModified": 1712014858,
+        "narHash": "sha256-sB4SWl2lX95bExY2gMFG5HIzvva5AVMJd4Igm+GpZNw=",
         "owner": "hercules-ci",
         "repo": "flake-parts",
-        "rev": "f7b3c975cf067e56e7cda6cb098ebe3fb4d74ca2",
+        "rev": "9126214d0a59633752a136528f5f3b9aa8565b7d",
         "type": "github"
       },
       "original": {
@@ -20,11 +20,11 @@
     },
     "haskell-flake": {
       "locked": {
-        "lastModified": 1711149116,
-        "narHash": "sha256-tccTtjRvxrhSJkCnmNwaPrq0DDM3UsM0uiDyW4uJXXc=",
+        "lastModified": 1713084600,
+        "narHash": "sha256-qL7LV2MtwJ+1Xasg1TjSUmoE7yrRuXPqxpPlKjLE0SE=",
         "owner": "srid",
         "repo": "haskell-flake",
-        "rev": "6ae8a85071adfe08d70d9963c526947403c6c070",
+        "rev": "847292fc793a5c15c873e52e7751ee4267ef32a0",
         "type": "github"
       },
       "original": {
@@ -35,11 +35,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1711163522,
-        "narHash": "sha256-YN/Ciidm+A0fmJPWlHBGvVkcarYWSC+s3NTPk/P+q3c=",
+        "lastModified": 1712963716,
+        "narHash": "sha256-WKm9CvgCldeIVvRz87iOMi8CFVB1apJlkUT4GGvA0iM=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "44d0940ea560dee511026a53f0e2e2cde489b4d4",
+        "rev": "cfd6b5fc90b15709b780a5a1619695a88505a176",
         "type": "github"
       },
       "original": {
@@ -52,11 +52,11 @@
     "nixpkgs-lib": {
       "locked": {
         "dir": "lib",
-        "lastModified": 1709237383,
-        "narHash": "sha256-cy6ArO4k5qTx+l5o+0mL9f5fa86tYUX3ozE1S+Txlds=",
+        "lastModified": 1711703276,
+        "narHash": "sha256-iMUFArF0WCatKK6RzfUJknjem0H9m4KgorO/p3Dopkk=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "1536926ef5621b09bba54035ae2bb6d806d72ac8",
+        "rev": "d8fe5e6c92d0d190646fb9f1056741a229980089",
         "type": "github"
       },
       "original": {
@@ -98,11 +98,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1710781103,
-        "narHash": "sha256-nehQK/XTFxfa6rYKtbi8M1w+IU1v5twYhiyA4dg1vpg=",
+        "lastModified": 1711963903,
+        "narHash": "sha256-N3QDhoaX+paWXHbEXZapqd1r95mdshxToGowtjtYkGI=",
         "owner": "numtide",
         "repo": "treefmt-nix",
-        "rev": "7ee5aaac63c30d3c97a8c56efe89f3b2aa9ae564",
+        "rev": "49dc4a92b02b8e68798abd99184f228243b6e3ac",
         "type": "github"
       },
       "original": {

flake.nix

@@ -42,7 +42,7 @@
 
           # Development shell configuration
           devShell = {
-            hlsCheck.enable = false;
+            hlsCheck.enable = true;
           };
 
           # What should haskell-flake add to flake outputs?

fourmolu.yaml

@@ -0,0 +1,16 @@
+# Generated from web app, for more information, see: https://fourmolu.github.io/config/
+indentation: 4
+column-limit: none
+function-arrows: leading
+comma-style: trailing
+import-export-style: diff-friendly
+indent-wheres: false
+record-brace-space: true
+newlines-between-decls: 1
+haddock-style: multi-line
+haddock-style-module: single-line
+let-style: auto
+in-style: right-align
+single-constraint-parens: always
+unicode: never
+respectful: false

src/Main.hs

@@ -25,16 +25,14 @@ import System.Environment qualified as SE
 data HuffmanTree a
   = Leaf a
   | Node
-      { left :: HuffmanTree a
-      , right :: HuffmanTree a
-      }
+      {left :: HuffmanTree a, right :: HuffmanTree a}
   deriving (Eq, Ord, Show, Generic, C.Serialize)
 
 data TreeDir = L | R deriving (Eq, Ord, Show, Generic, C.Serialize)
 
 findTreeDirections :: forall a. (Ord a) => HuffmanTree a -> M.Map a [TreeDir]
 findTreeDirections (Leaf a) = M.singleton a []
-findTreeDirections (Node{..}) = M.union (rec' L left) (rec' R right)
+findTreeDirections (Node {..}) = M.union (rec' L left) (rec' R right)
  where
   rec' :: TreeDir -> HuffmanTree a -> M.Map a [TreeDir]
   rec' dir = M.map (dir :) . findTreeDirections
@@ -42,19 +40,18 @@ findTreeDirections (Node{..}) = M.union (rec' L left) (rec' R right)
 decompress :: forall a. (Ord a, Integral a, B.FiniteBits a) => Maybe ([TreeDir], HuffmanTree a) -> Maybe [a]
 decompress Nothing = Just []
 decompress (Just (treeDirs, tree)) = decompress' treeDirs
-  where
+ where
+  decompress' :: [TreeDir] -> Maybe [a]
+  decompress' [] = Just []
+  decompress' xs = case nextLeaf xs tree of
+    Nothing -> Nothing
+    Just (x, remainingDirs) -> (x :) <$> decompress' remainingDirs
 
-    decompress' :: [TreeDir] -> Maybe [a]
-    decompress' [] = Just []
-    decompress' xs = case nextLeaf xs tree of
-      Nothing -> Nothing
-      Just (x, remainingDirs) -> (x :) <$> decompress' remainingDirs
-
-    nextLeaf :: [TreeDir] -> HuffmanTree a -> Maybe (a, [TreeDir])
-    nextLeaf xs (Leaf a) = Just (a, xs)
-    nextLeaf [] _ = Nothing
-    nextLeaf (L:xs) (Node {..}) = nextLeaf xs left
-    nextLeaf (R:xs) (Node {..}) = nextLeaf xs right
+  nextLeaf :: [TreeDir] -> HuffmanTree a -> Maybe (a, [TreeDir])
+  nextLeaf xs (Leaf a) = Just (a, xs)
+  nextLeaf [] _ = Nothing
+  nextLeaf (L : xs) (Node {..}) = nextLeaf xs left
+  nextLeaf (R : xs) (Node {..}) = nextLeaf xs right
 
 compress :: forall a. (Ord a, Integral a, B.FiniteBits a) => BS.ByteString -> Maybe ([TreeDir], HuffmanTree a)
 compress bs =
@@ -77,7 +74,7 @@ compress bs =
 testCompression :: forall a. (Ord a, Eq a, Integral a, B.FiniteBits a) => D.Proxy a -> BS.ByteString -> Bool
 testCompression _ bs = ((Just . toBitsList $ bs) :: Maybe [a]) == (decompress . compress $ bs)
 
-encodeCompressed :: C.Serialize a => Maybe ([TreeDir], HuffmanTree a) -> BS.ByteString
+encodeCompressed :: (C.Serialize a) => Maybe ([TreeDir], HuffmanTree a) -> BS.ByteString
 encodeCompressed = C.encode . fmap (Bi.first encodeTreeDirs)
  where
   encodeTreeDirs = BV.cloneToByteString . V.fromList . map (BV.Bit . (== R))
@@ -122,12 +119,12 @@ finiteBitUncons bs =
   rest :: BS.ByteString
   (takenBytes, rest) = BS.splitAt numBytes bs
 
-compressionRatioFor ::
-  forall a.
-  (Integral a, B.FiniteBits a, Ord a, C.Serialize a) =>
-  D.Proxy a ->
-  BS.ByteString ->
-  Double
+compressionRatioFor
+  :: forall a
+   . (Integral a, B.FiniteBits a, Ord a, C.Serialize a)
+  => D.Proxy a
+  -> BS.ByteString
+  -> Double
 compressionRatioFor proxy bs =
   (/ (fromIntegral . BS.length $ bs))
     . fromIntegral