From da118c3c7e4b114ed3dbe546171145b52808c261 Mon Sep 17 00:00:00 2001
From: Sam Weaver <sweaver@relaypro.com>
Date: Fri, 25 Oct 2024 10:21:17 -0400
Subject: [PATCH 1/3] Fix Symbol.__eq__ (fixes #1476)

---
 lark/grammar.py       | 3 ++-
 tests/test_grammar.py | 7 +++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/lark/grammar.py b/lark/grammar.py
index 1d226d9..cf4f40b 100644
--- a/lark/grammar.py
+++ b/lark/grammar.py
@@ -16,7 +16,8 @@ class Symbol(Serialize):
         self.name = name
 
     def __eq__(self, other):
-        assert isinstance(other, Symbol), other
+        if not isinstance(other, Symbol):
+            return False
         return self.is_term == other.is_term and self.name == other.name
 
     def __ne__(self, other):
diff --git a/tests/test_grammar.py b/tests/test_grammar.py
index 624b079..52425db 100644
--- a/tests/test_grammar.py
+++ b/tests/test_grammar.py
@@ -6,7 +6,7 @@ from unittest import TestCase, main
 from lark import Lark, Token, Tree, ParseError, UnexpectedInput
 from lark.load_grammar import GrammarError, GRAMMAR_ERRORS, find_grammar_errors, list_grammar_imports
 from lark.load_grammar import FromPackageLoader
-
+from lark.grammar import Symbol
 
 class TestGrammar(TestCase):
     def setUp(self):
@@ -296,8 +296,11 @@ class TestGrammar(TestCase):
         p.parse('ab')
 
 
+    def test_symbol_eq(self):
+        a = None
+        b = Symbol("abc")
 
-
+        self.assertNotEqual(a, b)
 
 
 if __name__ == '__main__':

From 3ac48c1cd547a1971c83db15f1c285145a6fc3de Mon Sep 17 00:00:00 2001
From: Sam Weaver <sweaver@relaypro.com>
Date: Fri, 25 Oct 2024 13:30:46 -0400
Subject: [PATCH 2/3] Adjust behaviour in #1481 to raise a NotImplementedError

---
 lark/grammar.py       | 6 +++++-
 tests/test_grammar.py | 8 ++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/lark/grammar.py b/lark/grammar.py
index cf4f40b..fdf1c23 100644
--- a/lark/grammar.py
+++ b/lark/grammar.py
@@ -16,8 +16,12 @@ class Symbol(Serialize):
         self.name = name
 
     def __eq__(self, other):
-        if not isinstance(other, Symbol):
+        if other is None:
             return False
+        if not isinstance(other, Symbol):
+            raise NotImplementedError(
+                f"Comparing a Symbol with type {type(other).__name__} is not implemented"
+            )
         return self.is_term == other.is_term and self.name == other.name
 
     def __ne__(self, other):
diff --git a/tests/test_grammar.py b/tests/test_grammar.py
index 52425db..5455b6b 100644
--- a/tests/test_grammar.py
+++ b/tests/test_grammar.py
@@ -302,6 +302,14 @@ class TestGrammar(TestCase):
 
         self.assertNotEqual(a, b)
 
+        a = dict()
+
+        self.assertRaisesRegex(
+            NotImplementedError,
+            r"Comparing a Symbol with type dict is not implemented",
+            lambda: a == b,
+        )
+
 
 if __name__ == '__main__':
     main()

From 9d35d1b5e15102f9b2462c30c05449d9eb8bad8c Mon Sep 17 00:00:00 2001
From: Sam Weaver <sweaver@relaypro.com>
Date: Fri, 25 Oct 2024 15:51:05 -0400
Subject: [PATCH 3/3] Adjust behaviour in #1481 to return NotImplemented

---
 lark/grammar.py       | 6 +-----
 tests/test_grammar.py | 8 --------
 2 files changed, 1 insertion(+), 13 deletions(-)

diff --git a/lark/grammar.py b/lark/grammar.py
index fdf1c23..016496b 100644
--- a/lark/grammar.py
+++ b/lark/grammar.py
@@ -16,12 +16,8 @@ class Symbol(Serialize):
         self.name = name
 
     def __eq__(self, other):
-        if other is None:
-            return False
         if not isinstance(other, Symbol):
-            raise NotImplementedError(
-                f"Comparing a Symbol with type {type(other).__name__} is not implemented"
-            )
+            return NotImplemented
         return self.is_term == other.is_term and self.name == other.name
 
     def __ne__(self, other):
diff --git a/tests/test_grammar.py b/tests/test_grammar.py
index 5455b6b..52425db 100644
--- a/tests/test_grammar.py
+++ b/tests/test_grammar.py
@@ -302,14 +302,6 @@ class TestGrammar(TestCase):
 
         self.assertNotEqual(a, b)
 
-        a = dict()
-
-        self.assertRaisesRegex(
-            NotImplementedError,
-            r"Comparing a Symbol with type dict is not implemented",
-            lambda: a == b,
-        )
-
 
 if __name__ == '__main__':
     main()