Re: [Chicken-users] dynamic unbound-variable-value procedures?

[felix winkelmann]

On 1/28/06, Arto Bendiken <address@hidden> wrote:
>
> However, presumably there must be some way for the hook procedure to
> decide whether to perform, say, a `cadadar' operation instead of a
> `cadddar', but I haven't managed to figure it out. I looked at the
> variables beginning with ##sys... to see if there was some global I
> could peruse in the handler, and skimmed through the relevant portions
> of runtime.c for Chicken 2.2, but no luck so far.
>
> Suggestions, or a "no, not possible", appreciated :-)

Unfortunately this is currently not possible. I could
come up with a C-based solution, but the retrieval (and check)
of a toplevel variable is not done in a context that allows
calling a user-supplied Scheme procedure.
That said, with some minor modifications it is possible to
code this in C, but callbacks into Scheme are not possible,
so it's use may be somewhat awkward.


cheers,
felix