diff --git a/doc_comments_ai/treesitter/treesitter_hs.py b/doc_comments_ai/treesitter/treesitter_hs.py
index a9644b7..b595d3b 100644
--- a/doc_comments_ai/treesitter/treesitter_hs.py
+++ b/doc_comments_ai/treesitter/treesitter_hs.py
@@ -1,6 +1,4 @@
 import tree_sitter
-from typing import List, Dict
-
 
 from doc_comments_ai.constants import Language
 from doc_comments_ai.treesitter.treesitter import (Treesitter,
@@ -10,9 +8,7 @@
 
 class TreesitterHaskell(Treesitter):
     def __init__(self):
-        super().__init__(
-            Language.HASKELL, "function", "variable", "comment"
-        )
+        super().__init__(Language.HASKELL, "function", "variable", "comment")
 
     def parse(self, file_bytes: bytes) -> list[TreesitterMethodNode]:
         self.tree = self.parser.parse(file_bytes)
@@ -23,10 +19,15 @@ def parse(self, file_bytes: bytes) -> list[TreesitterMethodNode]:
             doc_comment = method["doc_comment"]
             source_code = None
             if method["method"].type == "signature":
-                sc = map(lambda x : "\n" + x.text.decode() if x.type == "function" else "", method["method"].children)
+                sc = map(
+                    lambda x: "\n" + x.text.decode() if x.type == "function" else "",
+                    method["method"].children,
+                )
                 source_code = method["method"].text.decode() + "".join(sc)
             result.append(
-                TreesitterMethodNode(method_name, doc_comment, source_code, method["method"])
+                TreesitterMethodNode(
+                    method_name, doc_comment, source_code, method["method"]
+                )
             )
         return result
 
@@ -34,7 +35,7 @@ def _query_all_methods(
         self,
         node: tree_sitter.Node,
     ):
-        methods: List[Dict[tree_sitter.Node, tree_sitter.Node]] = []
+        methods = []
         if node.type == self.method_declaration_identifier:
             doc_comment_node = None
             if (
@@ -43,11 +44,15 @@ def _query_all_methods(
             ):
                 doc_comment_node = node.prev_named_sibling.text.decode()
             else:
-                if node.prev_named_sibling.type == "signature":
+                if (
+                    node.prev_named_sibling
+                    and node.prev_named_sibling.type == "signature"
+                ):
                     prev_node = node.prev_named_sibling
                     if (
                         prev_node.prev_named_sibling
-                        and prev_node.prev_named_sibling.type == self.doc_comment_identifier
+                        and prev_node.prev_named_sibling.type
+                        == self.doc_comment_identifier
                     ):
                         doc_comment_node = prev_node.prev_named_sibling.text.decode()
                     prev_node.children.append(node)
@@ -58,8 +63,12 @@ def _query_all_methods(
                 current = self._query_all_methods(child)
                 if methods and current:
                     previous = methods[-1]
-                    if self._query_method_name(previous["method"]) == self._query_method_name(current[0]["method"]):
-                        previous["method"].children.extend(map(lambda x: x["method"], current))
+                    if self._query_method_name(
+                        previous["method"]
+                    ) == self._query_method_name(current[0]["method"]):
+                        previous["method"].children.extend(
+                            map(lambda x: x["method"], current)
+                        )
                         methods = methods[:-1]
                         methods.append(previous)
                     else: