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

[Arto Bendiken]

Hi,

Since it seems possible to set the value of
`##sys#unbound-variable-value-hook' to a procedure, I was trying to do
the following:

;;; dynamic c*****r handler
(unbound-variable-value
  (lambda (list)
    ; how to find out the symbol by which we ended up here?
    ...))

(cadadar a-list-of-lists)

I found a similar question in the mailing list archives, relating to
an attempt to use `invalid-procedure-call-handler' for this purpose,
followed by a suggestion by Felix to use `unbound-variable-value'
instead:
http://lists.gnu.org/archive/html/chicken-users/2005-03/msg00044.html

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 :-)

--
Arto Bendiken
http://bendiken.net/