chore: drop tree-grepper

Regresses in that we only support Haskell for now, as Elm, Nix or Bash
are not available as tree-sitter-* Haskell packages.

15 files changed, 268 insertions, 351 deletions

diff --git a/anissue.cabal b/anissue.cabal
index d053af8..0bad4b0 100644
--- a/anissue.cabal
+++ b/anissue.cabal
@@ -67,6 +67,8 @@ executable anissue
     -- Modules included in this executable, other than Main.
     other-modules:
       Cache
+      Comment
+      Comment.Language
       Data.List.Extra
       Debug
       Die
@@ -92,10 +94,6 @@ executable anissue
       Render
       Settings
       Text.Diff.Extra
-      TreeGrepper.Comment
-      TreeGrepper.FileType
-      TreeGrepper.Match
-      TreeGrepper.Result
       Tuple
 
     -- LANGUAGE extensions used by modules in this package.
@@ -122,6 +120,8 @@ executable anissue
                       terminal-size,
                       text,
                       time,
+                      tree-sitter,
+                      tree-sitter-haskell,
                       typed-process,
                       xdg-basedir,
                       yaml
diff --git a/anissue.nix b/anissue.nix
index c2113f0..95d7cf8 100644
--- a/anissue.nix
+++ b/anissue.nix
@@ -12,7 +12,6 @@
 , ncurses
 , nix-gitignore
 , stdenv
-, tree-grepper
 }:
 stdenv.mkDerivation {
   name = "anissue";
@@ -26,16 +25,7 @@ stdenv.mkDerivation {
       wrapProgram $out/share/$(basename $bin) \
         --argv0 ''' \
         --set PATH ${lib.makeBinPath [
-          coreutils
-          docopts
-          findutils
-          gawk
           git
-          gnugrep
-          gnused
-          jq
-          ncurses
-          tree-grepper
         ]}
     done
     ln -s $out/share/anissue.sh $out/bin/anissue
diff --git a/app/Comment.hs b/app/Comment.hs
new file mode 100644
index 0000000..558778b
--- /dev/null
+++ b/app/Comment.hs
@@ -0,0 +1,182 @@
+module Comment
+  ( Comment (..),
+    Point (..),
+    getComments,
+    extractComments,
+    CommentStyle (..),
+    uncomment,
+    comment,
+  )
+where
+
+import Comment.Language
+import Control.Applicative (liftA2)
+import Control.Exception (catch)
+import Control.Monad
+import Data.Binary (Binary)
+import Data.ByteString qualified as B
+import Data.List (find, sortBy)
+import Data.List.NonEmpty qualified as N
+import Data.Maybe (fromMaybe)
+import Data.Ord (comparing)
+import Data.Text qualified as T
+import Data.Text.Encoding qualified as T
+import Data.Text.Lazy qualified as LT
+import Exception qualified as E
+import Foreign.C.String
+import Foreign.Marshal.Alloc (malloc)
+import Foreign.Marshal.Array (mallocArray, peekArray)
+import Foreign.Ptr (nullPtr)
+import Foreign.Storable
+import GHC.Generics (Generic)
+import Git qualified
+import System.FilePath (takeExtension)
+import TreeSitter.Node qualified as S
+import TreeSitter.Parser qualified as S
+import TreeSitter.Tree qualified as S
+
+data Comment = Comment
+  { text :: T.Text,
+    language :: Language,
+    start :: Int,
+    end :: Int,
+    startPoint :: Point,
+    endPoint :: Point,
+    filePath :: FilePath
+  }
+  deriving (Eq, Show)
+
+data Point = Point
+  { row :: Int,
+    column :: Int
+  }
+  deriving (Eq, Show, Generic, Binary)
+
+getComments :: Git.CommitHash -> FilePath -> IO [Comment]
+getComments commitHash filePath =
+  fmap mergeLineComments
+    . extractComments filePath language
+    . (T.encodeUtf8 . LT.toStrict)
+    =<< catch
+      (Git.readTextFileOf commitHash filePath)
+      (\(_ :: E.ProcessException) -> pure "")
+  where
+    language = fromExtension (takeExtension filePath)
+
+    mergeLineComments :: [Comment] -> [Comment]
+    mergeLineComments =
+      map mergeGroup
+        . chainsBy (\a b -> a.endPoint.row + 1 == b.startPoint.row)
+        . sortBy (comparing (liftA2 (,) (.start) (.end)))
+
+    mergeGroup :: N.NonEmpty Comment -> Comment
+    mergeGroup css@(c N.:| cs) =
+      c
+        { text = T.unlines (map (.text) (c : cs)),
+          start = first.start,
+          end = last.end,
+          startPoint = first.startPoint,
+          endPoint = last.endPoint
+        }
+      where
+        first = N.head css
+        last = N.last css
+
+    {- A version of `Data.List.groupBy` that uses the last added group-member for comparison with new candidates for the group. `Data.List.groupBy` uses the initial member for all subsequent comparisons. -}
+    chainsBy :: (a -> a -> Bool) -> [a] -> [N.NonEmpty a]
+    chainsBy p = reverse . map N.reverse . go []
+      where
+        go rs [] = rs
+        go [] (x : xs) = go [N.singleton x] xs
+        go (ass@((a N.:| as) : rs)) (x : xs)
+          | p a x = go ((x N.:| a : as) : rs) xs
+          | otherwise = go (N.singleton x : ass) xs
+
+extractComments :: FilePath -> Language -> B.ByteString -> IO [Comment]
+extractComments filePath language str' = do
+  S.withParser (parser language) $ \parser -> do
+    B.useAsCStringLen str' $ \(str, len) -> do
+      tree <- S.ts_parser_parse_string parser nullPtr str len
+      S.withRootNode tree $ \node -> do
+        map
+          ( \n' ->
+              let start = fromIntegral $ S.nodeStartByte n'
+                  end = fromIntegral $ S.nodeEndByte n'
+                  text = T.decodeUtf8 . B.take (end - start) . B.drop start $ str'
+                  startPoint = fromTSPoint (S.nodeStartPoint n')
+                  endPoint = fromTSPoint (S.nodeEndPoint n')
+
+                  fromTSPoint (S.TSPoint {..}) = Point (fromIntegral pointRow + 1) (fromIntegral pointColumn + 1)
+               in Comment {..}
+          )
+          <$> (commentsFromNodeRec language =<< peek node)
+
+commentsFromNodeRec :: Language -> S.Node -> IO [S.Node]
+commentsFromNodeRec language =
+  (filterM (isCommentNode language) =<<)
+    . childNodesFromNodeRec
+
+isCommentNode :: Language -> S.Node -> IO Bool
+isCommentNode language n =
+  (`elem` (nodeTypes language)) <$> peekCString (S.nodeType n)
+
+childNodesFromNodeRec :: S.Node -> IO [S.Node]
+childNodesFromNodeRec n = do
+  ns' <- childNodesFromNode n
+  ns <- concat <$> mapM childNodesFromNodeRec ns'
+  pure $ n : ns
+
+childNodesFromNode :: S.Node -> IO [S.Node]
+childNodesFromNode n = do
+  let numChildren = fromIntegral (S.nodeChildCount n)
+  ns <- mallocArray numChildren
+  tsNode <- malloc
+  poke tsNode (S.nodeTSNode n)
+  S.ts_node_copy_child_nodes tsNode ns
+  peekArray numChildren ns
+
+data CommentStyle
+  = LineStyle T.Text
+  | BlockStyle T.Text T.Text
+  deriving (Eq, Show, Generic, Binary)
+
+comment :: CommentStyle -> T.Text -> T.Text
+comment (LineStyle linePrefix) = T.unlines . map ((linePrefix <> " ") <>) . T.lines
+comment (BlockStyle blockStart blockEnd) = (blockStart <>) . (<> blockEnd)
+
+uncomment :: Language -> T.Text -> (CommentStyle, T.Text)
+uncomment language rawText =
+  maybe
+    ( ( LineStyle (lineStart language),
+        stripLineComments (lineStart language) text
+      )
+    )
+    ( \(blockStart, blockEnd) ->
+        ( BlockStyle blockStart blockEnd,
+          stripBlockComment blockStart blockEnd text
+        )
+    )
+    $ do
+      (blockStarts, blockEnd) <- block language
+      (,blockEnd) <$> find (`T.isPrefixOf` text) blockStarts
+  where
+    text = stripLines rawText
+    stripLines = T.intercalate "\n" . map T.strip . T.lines
+
+stripLineComments :: T.Text -> T.Text -> T.Text
+stripLineComments lineStart text =
+  onLines
+    ( \line ->
+        fromMaybe line . fmap T.stripStart $
+          T.stripPrefix lineStart line
+    )
+    text
+  where
+    onLines f = T.intercalate "\n" . map f . T.lines
+
+stripBlockComment :: T.Text -> T.Text -> T.Text -> T.Text
+stripBlockComment blockStart blockEnd text =
+  T.strip
+    . (fromMaybe text . T.stripSuffix blockEnd)
+    . (fromMaybe text . T.stripPrefix blockStart)
+    $ text
diff --git a/app/Comment/Language.hs b/app/Comment/Language.hs
new file mode 100644
index 0000000..009c6e6
--- /dev/null
+++ b/app/Comment/Language.hs
@@ -0,0 +1,39 @@
+module Comment.Language
+  ( Language (..),
+    fromExtension,
+    parser,
+    lineStart,
+    block,
+    nodeTypes,
+  )
+where
+
+import Control.Exception (throw)
+import Data.Binary (Binary)
+import Data.Text qualified as T
+import Exception qualified as E
+import Foreign.Ptr (Ptr)
+import GHC.Generics (Generic)
+import TreeSitter.Haskell qualified as S
+import TreeSitter.Language qualified as S
+
+data Language
+  = Haskell
+  deriving (Eq, Show, Generic, Binary)
+
+fromExtension :: String -> Language
+fromExtension ".hs" = Haskell
+fromExtension ext = throw $ E.UnknownFileExtension ext
+
+-- TODO add languages elm, shell, nix
+parser :: Language -> Ptr S.Language
+parser Haskell = S.tree_sitter_haskell
+
+lineStart :: Language -> T.Text
+lineStart Haskell = "--"
+
+block :: Language -> Maybe ([T.Text], T.Text)
+block Haskell = Just (["{-"], "-}")
+
+nodeTypes :: Language -> [String]
+nodeTypes Haskell = ["comment"]
diff --git a/app/Extract.hs b/app/Extract.hs
new file mode 100644
index 0000000..e351898
--- /dev/null
+++ b/app/Extract.hs
@@ -0,0 +1,17 @@
+module Extract where
+
+data Comment = Comment
+  { -- result fields
+    file :: String,
+    file_type :: FileType,
+    -- match fields
+    kind :: String,
+    name :: String,
+    text :: T.Text,
+    start :: Position,
+    end :: Position
+  }
+
+extractComments :: T.Text -> IO [Comment]
+extractComments = do
+  parer <- ts_parser_new
diff --git a/app/Git.hs b/app/Git.hs
index a3c82fa..d308026 100644
--- a/app/Git.hs
+++ b/app/Git.hs
@@ -105,6 +105,9 @@ getCommitOf commitHash@(Commit hash) = do
                 }
       _ -> throwIO E.NoCommits
 
+-- TODO Fix `readTextFileOf`
+--
+-- Handle file does not exist in `WorkingTree` case.
 readTextFileOf :: CommitHash -> FilePath -> IO LT.Text
 readTextFileOf WorkingTree filePath = LT.readFile filePath
 readTextFileOf (Commit hash) filePath =
diff --git a/app/History.hs b/app/History.hs
index 5b2dab3..d9f434d 100644
--- a/app/History.hs
+++ b/app/History.hs
@@ -6,6 +6,7 @@ where
 
 import CMark qualified as D
 import Cache (cachedMaybe)
+import Comment qualified as G
 import Control.Exception (catch, handle, try)
 import Data.Binary (Binary)
 import Data.ByteString.Lazy qualified as LB
@@ -35,7 +36,6 @@ import Render qualified as P
 import System.FilePath ((</>))
 import System.IO.Temp (withSystemTempDirectory)
 import System.Process.Typed (setWorkingDir)
-import TreeGrepper.Comment qualified as G
 import Tuple ()
 
 -- TODO Reduce cached data size
@@ -129,10 +129,10 @@ fromComment commitHash comment = do
          in I.Issue
               { title = title,
                 description = N.nonEmpty parseResult.paragraphs,
-                file = comment.file,
+                file = comment.filePath,
                 provenance = provenance,
-                start = comment.start,
-                end = comment.end,
+                startPoint = comment.startPoint,
+                endPoint = comment.endPoint,
                 tags = I.extractTags parseResult.tags,
                 markers = markers,
                 rawText = rawText,
@@ -143,7 +143,7 @@ fromComment commitHash comment = do
     )
       <$> I.parse I.issueMarkers (D.commonmarkToNode [] rawText)
   where
-    (commentStyle, rawText) = G.uncomment comment.file_type comment.text
+    (commentStyle, rawText) = G.uncomment comment.language comment.text
 
 propagate :: CommitHash -> History -> Scramble -> IO History
 propagate commitHash oldHistory scramble = do
diff --git a/app/Issue.hs b/app/Issue.hs
index 83e7141..9ae3de8 100644
--- a/app/Issue.hs
+++ b/app/Issue.hs
@@ -10,6 +10,7 @@ module Issue
 where
 
 import CMark qualified as D
+import Comment qualified as G
 import Data.Binary (Binary (..))
 import Data.List.NonEmpty (NonEmpty)
 import Data.Text qualified as T
@@ -21,8 +22,6 @@ import Git (Author (..), Commit (..))
 import Issue.Provenance (Provenance (..))
 import Issue.Tag (Tag (..))
 import Render qualified as P
-import TreeGrepper.Comment qualified as G
-import TreeGrepper.Match qualified as G
 import Prelude hiding (id)
 
 data Issue = Issue
@@ -30,8 +29,8 @@ data Issue = Issue
     description :: Maybe (NonEmpty D.Node),
     file :: String,
     provenance :: Provenance,
-    start :: G.Position,
-    end :: G.Position,
+    startPoint :: G.Point,
+    endPoint :: G.Point,
     tags :: [Tag],
     markers :: [T.Text],
     rawText :: T.Text,
@@ -78,12 +77,12 @@ replaceText :: Issue -> T.Text -> IO ()
 replaceText issue s' = T.writeFile issue.file . replace (indent (comment s')) =<< T.readFile issue.file
   where
     comment = T.intercalate "\n" . map T.strip . T.lines . G.comment issue.commentStyle
-    indent = T.intercalate "\n" . mapButFirst (T.replicate (issue.start.column - 1) " " <>) . T.lines
+    indent = T.intercalate "\n" . mapButFirst (T.replicate (issue.startPoint.column - 1) " " <>) . T.lines
     replace s t = before <> s <> after
       where
         t' = T.lines t
-        before = T.intercalate "\n" (mapLast (T.take (issue.start.column - 1)) (take issue.start.row t'))
-        after = T.unlines (mapFirst (T.drop issue.end.column) (drop (issue.end.row - 1) t'))
+        before = T.intercalate "\n" (mapLast (T.take (issue.startPoint.column - 1)) (take issue.startPoint.row t'))
+        after = T.unlines (mapFirst (T.drop issue.endPoint.column) (drop (issue.endPoint.row - 1) t'))
     mapFirst _ [] = []
     mapFirst f (x : xs) = f x : xs
     mapLast _ [] = []
diff --git a/app/TreeGrepper/Comment.hs b/app/TreeGrepper/Comment.hs
deleted file mode 100644
index 7c2ca90..0000000
--- a/app/TreeGrepper/Comment.hs
+++ /dev/null
@@ -1,149 +0,0 @@
-module TreeGrepper.Comment
-  ( Comment (..),
-    getComments,
-    CommentStyle (..),
-    uncomment,
-    comment,
-  )
-where
-
-import Control.Exception (catch, throw)
-import Data.Aeson qualified as A
-import Data.Binary (Binary)
-import Data.ByteString.Lazy.Char8 qualified as B
-import Data.Function ((&))
-import Data.List (find)
-import Data.Maybe (fromMaybe)
-import Data.Text qualified as T
-import Data.Text.Lazy.IO qualified as LT
-import Exception qualified as E
-import GHC.Generics (Generic)
-import Git qualified
-import Process (proc, sh)
-import System.Directory (createDirectoryIfMissing)
-import System.FilePath (takeDirectory, takeExtension, takeFileName, (</>))
-import System.IO.Temp (withSystemTempDirectory)
-import System.Process.Typed qualified as P
-import TreeGrepper.FileType (FileType (..))
-import TreeGrepper.FileType qualified as G
-import TreeGrepper.Match (Match (..), Position (..))
-import TreeGrepper.Match qualified as G
-import TreeGrepper.Result (Result (..))
-import TreeGrepper.Result qualified as G
-
-data Comment = Comment
-  { -- result fields
-    file :: String,
-    file_type :: FileType,
-    -- match fields
-    kind :: String,
-    name :: String,
-    text :: T.Text,
-    start :: Position,
-    end :: Position
-  }
-  deriving (Show, Generic)
-
-data CommentStyle
-  = LineStyle T.Text
-  | BlockStyle T.Text T.Text
-  deriving (Eq, Show, Generic, Binary)
-
-comment :: CommentStyle -> T.Text -> T.Text
-comment (LineStyle linePrefix) = T.unlines . map ((linePrefix <> " ") <>) . T.lines
-comment (BlockStyle blockStart blockEnd) = (blockStart <>) . (<> blockEnd)
-
-uncomment :: FileType -> T.Text -> (CommentStyle, T.Text)
-uncomment fileType rawText =
-  maybe
-    ( ( LineStyle info.lineStart,
-        stripLineComments (G.info fileType).lineStart text
-      )
-    )
-    ( \(blockInfo, blockStart) ->
-        ( BlockStyle blockStart blockInfo.blockEnd,
-          stripBlockComment blockStart blockInfo.blockEnd text
-        )
-    )
-    $ do
-      blockInfo <- info.block
-      (,) blockInfo <$> find (`T.isPrefixOf` text) blockInfo.blockStart
-  where
-    info = G.info fileType
-    text = stripLines rawText
-    stripLines = T.intercalate "\n" . map T.strip . T.lines
-
-stripLineComments :: T.Text -> T.Text -> T.Text
-stripLineComments lineStart text =
-  onLines
-    ( \line ->
-        fromMaybe line . fmap T.stripStart $
-          T.stripPrefix lineStart line
-    )
-    text
-  where
-    onLines f = T.intercalate "\n" . map f . T.lines
-
-stripBlockComment :: T.Text -> T.Text -> T.Text -> T.Text
-stripBlockComment blockStart blockEnd text =
-  T.strip
-    . (fromMaybe text . T.stripSuffix blockEnd)
-    . (fromMaybe text . T.stripPrefix blockStart)
-    $ text
-
-fromMatch :: Result -> Match -> Comment
-fromMatch Result {..} Match {..} = Comment {..}
-
-getComments :: Git.CommitHash -> FilePath -> IO [Comment]
-getComments commitHash fn = do
-  let ext = takeExtension fn
-  s <-
-    catch
-      (Git.readTextFileOf commitHash fn)
-      (\(_ :: E.ProcessException) -> pure "")
-  withSystemTempDirectory (takeFileName fn) $ \cwd -> do
-    createDirectoryIfMissing True (cwd </> takeDirectory fn)
-    LT.writeFile (cwd </> fn) s
-    concatMap (\result -> map (fromMatch result) result.matches)
-      . map fixTreeGrepper
-      . decode
-      <$> sh
-        ( ( proc
-              "tree-grepper % --query % % --format json"
-              fn
-              (treeGrepperLanguage ext)
-              (treeGrepperQuery ext)
-          )
-            & P.setWorkingDir cwd
-        )
-
-decode :: B.ByteString -> [Result]
-decode = either (throw . E.InvalidTreeGrepperResult) id . A.eitherDecode
-
-fixTreeGrepper :: G.Result -> G.Result
-fixTreeGrepper treeGrepperResult =
-  treeGrepperResult {G.matches = G.merge treeGrepperResult.matches}
-
-treeGrepperLanguage :: String -> String
-treeGrepperLanguage ext =
-  -- TODO Add support for all tree-grepper supported files
-  --
-  -- tree-grepper supported files can be listed through `tree-grepper
-  -- --languages`.
-  --
-  -- @backlog
-  case ext of
-    ".elm" -> "elm"
-    ".hs" -> "haskell"
-    ".nix" -> "nix"
-    ".sh" -> "sh"
-    _ -> throw (E.UnknownFileExtension ext)
-
-treeGrepperQuery :: String -> String
-treeGrepperQuery ext =
-  case ext of
-    ".elm" -> "([(line_comment) (block_comment)])"
-    ".hs" -> "(comment)"
-    ".nix" -> "(comment)"
-    ".sh" -> "(comment)"
-    _ -> throw (E.UnknownFileExtension ext)
diff --git a/app/TreeGrepper/FileType.hs b/app/TreeGrepper/FileType.hs
deleted file mode 100644
index 506cbc5..0000000
--- a/app/TreeGrepper/FileType.hs
+++ /dev/null
@@ -1,75 +0,0 @@
-module TreeGrepper.FileType
-  ( FileType (..),
-    all,
-    Info (..),
-    BlockInfo (..),
-    info,
-  )
-where
-
-import Data.Aeson (FromJSON (parseJSON))
-import Data.Binary (Binary)
-import Data.Text (Text)
-import GHC.Generics (Generic)
-import Prelude hiding (all)
-
-data FileType
-  = Elm
-  | Haskell
-  | Nix
-  | Shell
-  deriving (Eq, Show, Generic, Binary)
-
-instance FromJSON FileType where
-  parseJSON v =
-    parseJSON v >>= \case
-      "elm" -> pure Elm
-      "haskell" -> pure Haskell
-      "nix" -> pure Nix
-      "sh" -> pure Shell
-      fileType -> fail ("parsing file_type failed, got " ++ fileType)
-
-all :: [FileType]
-all =
-  [ Elm,
-    Haskell,
-    Nix,
-    Shell
-  ]
-
-data Info = Info
-  { exts :: [String],
-    lineStart :: Text,
-    block :: Maybe BlockInfo
-  }
-
-data BlockInfo = BlockInfo
-  { blockStart :: [Text],
-    blockEnd :: Text
-  }
-
-info :: FileType -> Info
-info Elm =
-  Info
-    { exts = [".elm"],
-      lineStart = "--",
-      block = Just BlockInfo {blockStart = ["{-|", "{-"], blockEnd = "-}"}
-    }
-info Haskell =
-  Info
-    { exts = [".hs"],
-      lineStart = "--",
-      block = Just BlockInfo {blockStart = ["{-"], blockEnd = "-}"}
-    }
-info Nix =
-  Info
-    { exts = [".nix"],
-      lineStart = "#",
-      block = Just BlockInfo {blockStart = ["/*"], blockEnd = "*/"}
-    }
-info Shell =
-  Info
-    { exts = [".sh"],
-      lineStart = "#",
-      block = Nothing
-    }
diff --git a/app/TreeGrepper/Match.hs b/app/TreeGrepper/Match.hs
deleted file mode 100644
index 5d9479e..0000000
--- a/app/TreeGrepper/Match.hs
+++ /dev/null
@@ -1,69 +0,0 @@
-module TreeGrepper.Match
-  ( Match (..),
-    Position (..),
-    merge,
-  )
-where
-
-import Data.Aeson (FromJSON)
-import Data.Binary (Binary)
-import Data.Function (on)
-import Data.List (sortBy)
-import Data.List.NonEmpty (NonEmpty ((:|)))
-import Data.List.NonEmpty qualified as N
-import Data.Ord (comparing)
-import Data.Text (Text)
-import Data.Text qualified as T
-import GHC.Generics (Generic)
-
-data Match = Match
-  { kind :: String,
-    name :: String,
-    text :: Text,
-    start :: Position,
-    end :: Position
-  }
-  deriving (Show, Generic)
-
-instance FromJSON Match
-
-data Position = Position
-  { row :: Int,
-    column :: Int
-  }
-  deriving (Eq, Show, Generic, Binary)
-
-instance Ord Position where
-  compare = compare `on` (\p -> (p.row, p.column))
-
-instance FromJSON Position
-
-{- tree-grepper (tree-sitter) is unable to match sibling comments blocks as a whole. We thus merge matches if they are line-adjacent. -}
-merge :: [Match] -> [Match]
-merge matches =
-  map mergeGroup
-    . chainsBy (\a b -> a.end.row + 1 == b.start.row)
-    $ sortBy (comparing (.start)) matches
-
-mergeGroup :: NonEmpty Match -> Match
-mergeGroup (m :| ms) =
-  m
-    { text = text,
-      start = start,
-      end = end
-    }
-  where
-    mss = m : ms
-    text = T.unlines $ map (.text) mss
-    start = minimum $ map (.start) mss
-    end = maximum $ map (.end) mss
-
-{- A version of `Data.List.groupBy` that uses the last added group-member for comparison with new candidates for the group. `Data.List.groupBy` uses the initial member for all subsequent comparisons. -}
-chainsBy :: (a -> a -> Bool) -> [a] -> [NonEmpty a]
-chainsBy p = reverse . map N.reverse . go []
-  where
-    go rs [] = rs
-    go [] (x : xs) = go [N.singleton x] xs
-    go (ass@((a :| as) : rs)) (x : xs)
-      | p a x = go ((x :| a : as) : rs) xs
-      | otherwise = go (N.singleton x : ass) xs
diff --git a/app/TreeGrepper/Result.hs b/app/TreeGrepper/Result.hs
deleted file mode 100644
index 856871a..0000000
--- a/app/TreeGrepper/Result.hs
+++ /dev/null
@@ -1,15 +0,0 @@
-module TreeGrepper.Result (Result (..)) where
-
-import Data.Aeson (FromJSON)
-import GHC.Generics (Generic)
-import TreeGrepper.FileType (FileType)
-import TreeGrepper.Match (Match)
-
-data Result = Result
-  { file :: String,
-    file_type :: FileType,
-    matches :: [Match]
-  }
-  deriving (Show, Generic)
-
-instance FromJSON Result
diff --git a/default.nix b/default.nix
index 06709df..59d560e 100644
--- a/default.nix
+++ b/default.nix
@@ -1,6 +1,16 @@
 { pkgs ? import <nixpkgs> {
     overlays = [
-      (import ./pkgs)
+      (self: super: {
+        tree-sitter = super.tree-sitter.overrideAttrs (oldAttrs: {
+          buildInputs = oldAttrs.buildInputs or [ ] ++ [
+            super.makeWrapper
+          ];
+          postInstall = oldAttrs.postInstall or "" + ''
+            wrapProgram $out/bin/tree-sitter \
+              --prefix LD_LIBRARY_PATH : "${super.tree-sitter.withPlugins (_: self.tree-sitter.allGrammars)}"
+          '';
+        });
+      })
       (self: super: {
         anissue = pkgs.writers.writeDashBin "anissue" ''
           set -efu
@@ -22,7 +32,6 @@ let
           dependencies = [
             pkgs.coreutils
             pkgs.git
-            pkgs.tree-grepper
           ];
         };
         postInstall = ''
@@ -53,6 +62,7 @@ rec {
       pkgs.anissue
       pkgs.ghcid
       pkgs.haskell-language-server
+      pkgs.tree-sitter
     ] ++ anissue.passthru.dependencies;
     withHoogle = true;
     withHaddock = true;
diff --git a/pkgs/default.nix b/pkgs/default.nix
deleted file mode 100644
index 09ae05b..0000000
--- a/pkgs/default.nix
+++ /dev/null
@@ -1,5 +0,0 @@
-self: super: super.lib.composeManyExtensions [
-  (import ./tree-grepper.nix)
-]
-  self
-  super
diff --git a/pkgs/tree-grepper.nix b/pkgs/tree-grepper.nix
deleted file mode 100644
index 463bf6c..0000000
--- a/pkgs/tree-grepper.nix
+++ /dev/null
@@ -1,10 +0,0 @@
-self: super: {
-  # TODO package tree-grepper in Nixpkgs so that it can reuse <nixpkgs>
-  tree-grepper = (import (self.fetchFromGitHub {
-    owner = "aforemny";
-    repo = "tree-grepper";
-    rev = "af9d7e4380f5c1b12bc671216a219c1f01a640d7";
-    hash = "sha256-QteyQ/SfcXZ2VZTRl++gRHeaR/1qnsS8tiN1RLndW5Y=";
-  })).default;
-}
-