Make custom lexer more generic, #327

Author: Scony

gdtoolkit/parser/gdscript_indenter.py

@@ -117,31 +117,36 @@ def _dedent_lambda_at_token(self, token: Token):
         yield Token.new_borrow_pos(self.DEDENT_type, "N/A", token)
 
     def _current_token_is_just_after_lambda_header(self):
-        # TODO: handle newlines etc. in between tokens
-        return (
-            len(self.processed_tokens) > 0
-            and self.processed_tokens[-2].type == "COLON"
-            and self.processed_tokens[-3].type == "RPAR"
-            and self.processed_tokens[-4].type == "LPAR"
-            and (
-                self.processed_tokens[-5].type == "FUNC"
-                or (
-                    self.processed_tokens[-5].type == "NAME"
-                    and self.processed_tokens[-6].type == "FUNC"
-                )
-            )
-        ) or (
-            len(self.processed_tokens) > 0
-            and self.processed_tokens[-2].type == "COLON"
-            and self.processed_tokens[-3].type == "TYPE_HINT"
-            and self.processed_tokens[-4].value == "->"
-            and self.processed_tokens[-5].type == "RPAR"
-            and self.processed_tokens[-6].type == "LPAR"
-            and (
-                self.processed_tokens[-7].type == "FUNC"
-                or (
-                    self.processed_tokens[-7].type == "NAME"
-                    and self.processed_tokens[-8].type == "FUNC"
-                )
-            )
-        )
+        extra_rpars = [0]
+        pattern_functions = [
+            lambda t: t.type == "COLON",
+            lambda t: t.type == "RPAR",
+            lambda t: t.type == "LPAR" and extra_rpars[0] == 0,
+            lambda t: t.type == "FUNC",
+        ]
+
+        def lpar_accept_function(token: Token) -> bool:
+            if token.type == "RPAR":
+                extra_rpars[0] += 1
+            elif token.type == "LPAR":
+                if extra_rpars[0] <= 0:
+                    return False
+                extra_rpars[0] -= 1
+            return True
+
+        accept_functions = [
+            lambda t: t.type == "_NL",
+            lambda t: t.type in ["_NL", "TYPE_HINT"] or t.value == "->",
+            lpar_accept_function,
+            lambda t: t.type in ["_NL", "NAME"],
+        ]
+        i = 0
+        for processed_token in reversed(self.processed_tokens):
+            if i >= len(pattern_functions):
+                return True
+            if pattern_functions[i](processed_token):
+                i += 1
+                continue
+            if not accept_functions[i](processed_token):
+                return False
+        return i >= len(pattern_functions)

tests/valid-gd-scripts/bug_327_multiline_lambda.gd

@@ -4,3 +4,10 @@ func foo(new_button, button_name, menu, _game_flow):
 			var test := ""
 			_game_flow.ref.request_transition(menu[button_name].transition, menu[button_name].data)
 	)
+
+func bar(new_button, button_name, menu, _game_flow):
+	new_button.pressed.connect(
+		func(x=(1)) -> void:
+			var test := ""
+			_game_flow.ref.request_transition(menu[button_name].transition, menu[button_name].data)
+	)