merge

CHANGES.rst

@@ -1,7 +1,7 @@
 	.. contents::
 
 CHANGES
-=======
+*******
 
 5.0.3dev0
 ---------
@@ -52,7 +52,8 @@ Bugs
 # ``0`` with a given precision (like in ```0`3```) is now parsed as ``0``, an integer number.
 #. ``RandomSample`` with one list argument now returns a random ordering of the list items. Previously it would return just one item.
 #. Rules of the form ``pat->Condition[expr, cond]`` are handled as in WL. The same works for nested `Condition` expressions. Also, comparisons among these rules was improved.
-
+#. ``mathics.core.Pattern.create`` now catches the case when the input parameter is not an `Atom` or an `Expression`.
+
 
 Enhancements
 ++++++++++++

mathics/builtin/base.py

@@ -826,6 +826,11 @@ def get_string_value(self):
 
     def sameQ(self, expr) -> bool:
         """Mathics SameQ"""
+        if expr is self:
+            return True
+        # Otherwise, we need to convert
+        # self into an to expression
+        # to avoid an infinite loop...
         return self.to_expression().sameQ(expr)
 
     def do_format(self, evaluation, format):

mathics/core/pattern.py

@@ -86,9 +86,6 @@ def create(expr: BaseElement) -> "Pattern":
         by calling the method ``to_expression``, and then call the function
         again with this new object as input.
         """
-        if not isinstance(expr, (Atom, Expression)):
-            expr = expr.to_expression()
-
         name = expr.get_head_name()
         pattern_object = pattern_objects.get(name)
         if pattern_object is not None:
@@ -97,8 +94,10 @@ def create(expr: BaseElement) -> "Pattern":
             return AtomPattern(expr)
         elif isinstance(expr, Expression):
             return ExpressionPattern(expr)
-        # Otherwise, try to get an expression and
-        # call again.
+        # To handle Boxes and other possible objects that
+        # can be converted into expressions, convert expr to
+        # expression and call this function
+        # again:
         return Pattern.create(expr.to_expression())
 
     def match(