[Rd] proto and baseenv()

[hadley wickham]

> Presumably if I ask for p$a or p$b later, it's because I'm interesting
> in the value of "p$a" or "p$b" that I specifically put inside that
> environment.  Otherwise I would just ask for "a" or "b".  If I'm
> asking for "p$b" it the above case, that means I forgot to declare b
> inside p.  In this case there should be an error telling me that, not
> a silent substitution of the wrong quantity.
>
> If someone wanted to do the y$ls() thing, they could always
>
>> y <- proto(a=1)
>> with(y, ls())
> [1] "a"
>
> Another reason is that there are plenty of other programming languages
> that have similar structures and this behavior is very odd.  In
> standard languages asking for "b" inside the "p" object gives you an
> error, and no one complains.

You might want to have a look at the mutatr package which implements
prototype OO with the behaviour you're looking for (I think).  I also
have a paper available if you email me off list.

Hadley

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