On Jun 14, 2009, at 2:10 PM, Ramana Kumar wrote:
So, you have a library that may or may not export a macro, say let^,
and you have an expression that may or may not reference let^. If
the expression references let^, and let^ was not exported, which
would normally result in a syntax error, you want to defer the error
until run time instead of being signaled at macro-expansion time.
I actually don't want the error at all - I want to detect that let^ is
not exported and therefore remove the expression that references it
(or replace it with something). This can happen at macro expansion
time. Still not possible?
It's the same thing. You want to handle the syntax-error exception by
replacing the offending expression with another one of your choice.
The replacement may be just #f or (asserion-violation 'foo "unbound")
or whatever. Still, not possible to do correctly without hacking on
psyntax.
Aziz,,,
