x = m * y is even more explicit than x = m.vector_mult(y) because the * operator is side-effect free by convention, while a method like vector_mult() mig

x = m * y is even more explicit than x = m.vector_mult(y) because the * operator is side-effect free by convention, while a method like vector_mult() might or might not be mutating (i.e., it could work like the *= assignment operator).