Re: Change to variable interface request

[Maciej Stachowiak <mstachow@mit.edu>]

humeniuw@cadvision.com writes:
> Maciej Stachowiak wrote:
> 
> > 
> > In my opinion, it's a bad idea to expose the fact that Guile
> > implements variables as pairs to the user level. I suspect this
> > representation might change for certain classes of variables at least
> > when it comes time to tune Guile for speed.
> > 
> 
> The interface says nothing about the fact that variables are actually
> two pairs.  All it says is to bind a variable to the pair.  The action
> of variable-set! is then to modify the cdr of the pair.  How that is done
> is not revealed. :) (Maybe I should be a lawyer).  In this case its trivial 
> because the actual storage is a pair.  By creating this interface it becomes 
> trivial to write evals (in Guile, not C) that work over association lists,
> which is primarily what I need.  
> 

Well, viewed that way, I don't think Jim likes the idea of variables
with magic side effects, and I'd have to add that allowing only one
kind of magic side effect (mutating a cons cell) is worse, if
anything, than not allowing them at all. 

 - Maciej