since operator-overloading reached stage-1, would like to challenge one of its use-cases.
my experience with linear-algebra in javascript is mostly for high-level api's like svd-decomposition, matrix-minimization-algorithms, etc. in practice, these high-level api's would never use naive matrix/vector operators -- you commonly need to hand-code the for-loops yourself to take into account application-specific nan edge-cases, and malformed web-inputs.