Add return of NotImplemented to other binary operators (similar to PR #425), and add unit tests

1 files changed, 20 insertions, 0 deletions

diff --git a/pyparsing/core.py b/pyparsing/core.py
index fd5889a..54846f5 100644
--- a/pyparsing/core.py
+++ b/pyparsing/core.py
@@ -3940,6 +3940,8 @@ class And(ParseExpression):
     def __iadd__(self, other):
         if isinstance(other, str_type):
             other = self._literalStringClass(other)
+        if not isinstance(other, ParserElement):
+            return NotImplemented
         return self.append(other)  # And([self, other])
 
     def _checkRecursion(self, parseElementList):
@@ -4080,6 +4082,8 @@ class Or(ParseExpression):
     def __ixor__(self, other):
         if isinstance(other, str_type):
             other = self._literalStringClass(other)
+        if not isinstance(other, ParserElement):
+            return NotImplemented
         return self.append(other)  # Or([self, other])
 
     def _generateDefaultName(self) -> str:
@@ -4191,6 +4195,8 @@ class MatchFirst(ParseExpression):
     def __ior__(self, other):
         if isinstance(other, str_type):
             other = self._literalStringClass(other)
+        if not isinstance(other, ParserElement):
+            return NotImplemented
         return self.append(other)  # MatchFirst([self, other])
 
     def _generateDefaultName(self) -> str:
@@ -4291,6 +4297,13 @@ class Each(ParseExpression):
         self.initExprGroups = True
         self.saveAsList = True
 
+    def __iand__(self, other):
+        if isinstance(other, str_type):
+            other = self._literalStringClass(other)
+        if not isinstance(other, ParserElement):
+            return NotImplemented
+        return self.append(other)  # Each([self, other])
+
     def streamline(self) -> ParserElement:
         super().streamline()
         if self.exprs:
@@ -5216,6 +5229,10 @@ class Forward(ParseElementEnhance):
             del self.caller_frame
         if isinstance(other, str_type):
             other = self._literalStringClass(other)
+
+        if not isinstance(other, ParserElement):
+            return NotImplemented
+
         self.expr = other
         self.mayIndexError = self.expr.mayIndexError
         self.mayReturnEmpty = self.expr.mayReturnEmpty
@@ -5229,6 +5246,9 @@ class Forward(ParseElementEnhance):
         return self
 
     def __ilshift__(self, other) -> "Forward":
+        if not isinstance(other, ParserElement):
+            return NotImplemented
+
         return self << other
 
     def __or__(self, other) -> "ParserElement":