From a7712bb4690d2aa0804e88f557996ef06d78835c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beno=C3=AEt=20Legat?= <benoit.legat@gmail.com>
Date: Wed, 3 Jul 2024 19:24:01 +0200
Subject: [PATCH] Allow multiplication with different algebras

---
 src/arithmetic.jl | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/arithmetic.jl b/src/arithmetic.jl
index 9645323..b6c1e8d 100644
--- a/src/arithmetic.jl
+++ b/src/arithmetic.jl
@@ -127,6 +127,24 @@ function MA.operate_to!(
     return res
 end
 
+function mstructure(args::AbstractStarAlgebra...)
+    for arg in args
+        @assert arg == first(args)
+    end
+    return mstructure(basis(args[1]))
+end
+
+function MA.operate!(
+    ::UnsafeAddMul{typeof(*)},
+    res::AlgebraElement,
+    A::BasisTransformation,
+    args::Vararg{AlgebraElement,N},
+) where {N}
+    mstr = mstructure(algebra(res), algebra.(args)...)
+    MA.operate!(UnsafeAddMul(mstr), coeffs(res), coeffs.(args)...)
+    return res
+end
+
 function MA.operate!(
     ::UnsafeAddMul{typeof(*)},
     res::AlgebraElement,
@@ -137,7 +155,7 @@ function MA.operate!(
             @assert parent(res) == parent(arg)
         end
     end
-    mstr = mstructure(basis(res))
+    mstr = mstructure(basis(res), basis.(args)...)
     MA.operate!(UnsafeAddMul(mstr), coeffs(res), coeffs.(args)...)
     return res
 end