[R] overloading the generic primitive functions "+" and "["

[Hadley Wickham]

> Note how S3 methods are dispatched only by reference to the first
> argument (on the left of the operator). I think S4 beats this by
> having signatures that can dispatch depending on both arguments.

That's somewhat of a simplification for primitive binary operators. R
actually looks up the method for both input classes, and returns a
error if they are different.

Hadley

-- 
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/