Re: Emacs Lisp and Guile

[Richard Stallman]

    Right now, a variable is a strictly passive data container.  You can't
    intercept accesses to it.  A variable reference is a direct reference
    to memory, not a function call.  We would have to change this model to
    also allow 'active' variables that can run arbitrary code when they
    are accessed.

That is not what I am suggesting.  Variables in Emacs do not run
arbitrary code when accessed; I think that would be a misguided
feature.  However, Emacs enables the value to reside in various places
besides the symbol itself.

For instance, a variable can be forwarded to a C variable.  There are
three ways of doing this: the C variable holds an integer, the C
variable holds a Lisp object, or the C variable holds a boolean value
(0 means nil, non-0 means t).

A similar feature in Guile would be useful for many sorts of
application programs.

This is independent of the feature of buffer-local and frame-local
variable bindings.  Their implementations in Emacs are not totally
independent, but perhaps they could be implemented independently in
Guile.