At 21:30 Uhr +0100 04.01.2006, Christian wrote:
The problem is that my side-effecting pseudo parameter cannot be transparently used with parameterize.
Well, I forgot that one can specify a filter function, with which the signal initialization example can be solved.
The case which I ran into a few months ago, where I was disappointed to find that parameterize doesn't let me use ordinary functions, was different; IIRC I wanted kind of a *read* filter instead, for generating values on the fly -- I can't remember exactly what it was.
BTW I would also like to point out that proper-tail-calls-set! would better be turned into a parameter, so one could do stuff like:
(define (load-no-tco file) (parameterize ((current-proper-tail-calls #f)) (load file)))
I've also not found a function to query the current setting, thus currently I'm doing this instead:
(define (load-no-tco file) (proper-tail-calls-set! #f) (load file) (proper-tail-calls-set! #t))
but this changes the previous setting if it has not been #t.
Christian.