Add comments that MatAdd and MatMul probably shouldn't be subclassing from Add and Mul

asmeurer · asmeurer · commit c1b2e1ab4e22 · 2019-03-29T15:43:16.000-06:00
There are some test failures right now if you remove them, at least in the
printers because they are using the Add and Mul printers, possibly other
places as well. For now we can leave it be but leave a comment that we might
want to remove them if they cause problems.
diff --git a/sympy/matrices/expressions/matadd.py b/sympy/matrices/expressions/matadd.py
@@ -12,9 +12,8 @@
 from sympy.matrices.expressions.matexpr import (MatrixExpr, ShapeError,
     ZeroMatrix, GenericZeroMatrix)
 from sympy.utilities import default_sort_key, sift
-from sympy.core.operations import AssocOp
-
 
+# XXX: MatAdd should perhaps not subclass directly from Add
 class MatAdd(MatrixExpr, Add):
     """A Sum of Matrix Expressions
 
diff --git a/sympy/matrices/expressions/matmul.py b/sympy/matrices/expressions/matmul.py
@@ -1,7 +1,7 @@
 from __future__ import print_function, division
 
 from sympy import Number
-from sympy.core import Mul, Basic, sympify, Add
+from sympy.core import Mul, Basic, sympify
 from sympy.core.compatibility import range
 from sympy.functions import adjoint
 from sympy.matrices.expressions.transpose import transpose
@@ -12,7 +12,7 @@
 from sympy.matrices.expressions.matpow import MatPow
 from sympy.matrices.matrices import MatrixBase
 
-
+# XXX: MatMul should perhaps not subclass directly from Mul
 class MatMul(MatrixExpr, Mul):
     """
     A product of matrix expressions
