Implement MatScalarMul.to_repr

1 files changed, 7 insertions, 3 deletions

diff --git a/mdpoly/algebra.py b/mdpoly/algebra.py
index d087785..81fae18 100644
--- a/mdpoly/algebra.py
+++ b/mdpoly/algebra.py
@@ -640,15 +640,19 @@ class MatScalarMul(BinaryOp, MatrixExpr):
 
     def to_repr(self, repr_type: type, state: State) -> tuple[Repr, State]:
         """ See :py:meth:`mdpoly.abc.Expr.to_repr`. """
-        raise NotImplementedError
         r = repr_type()
 
         scalar_repr, state = self.left.to_repr(repr_type, state)
         mat_repr, state = self.right.to_repr(repr_type, state)
 
         for entry in mat_repr.entries():
-            for term in mat_repr.terms(entry):
-                ...
+            scalar_terms = scalar_repr.terms(MatrixIndex.scalar())
+            mat_terms = mat_repr.terms(entry)
+            for scalar_term, mat_term in product(scalar_terms, mat_terms):
+                term = PolyIndex.product(scalar_term, mat_term)
+
+                p = r.at(entry, term) + scalar_repr.at(entry, scalar_term) + mat_repr.at(entry, mat_term)
+                r.set(entry, term, p)
 
         return r, state