The matrix parameters of the *v functions are parameter lists, both according to OpenGL ES 2 and the WebGL specification. The current signature of the wrapper specifies only one slice.
Is there a specific reason that they only take one parameter?
In my code to wrap WebGL behind an OpenGL ES 2 interface I'm calling the JS function directly, as seen here.
Additionally: Should the signature be changed, may I suggest to have array types as parameters instead of slices? go-gl does that for instance.