[plt-scheme] some more frtime questions

From: Gregory Cooper (greg at cs.brown.edu)
Date: Thu Jan 31 14:57:40 EST 2008

> Hmm, it seems (I think) that the filter isn't working somehow, I'm
> getting the following error when I add it to my scene list. This could
> be something I'm doing wrong in my render-scene-list procedure:
> ../../../../usr/local/lib/plt/collects/fluxus-0.14/frisbee.ss::4553.:
> for-each: expects type <proper list> as 2nd argument, given:
> #(struct:signal () () #f #<procedure:...time/lang-ext.ss:278:34> 7
> #<continuation-mark-set> #<parameterization> (#(struct:signal
> #<struct:event-cons> (#<weak-box>) #f #<procedure:thunk> 6
> #<continuation-mark-set> #<parameterization> (#(struct:sign...; other
> arguments were: #<procedure>

Actually, what this looks like to me is that the list behavior (of
bullets) that you're putting in the scene list is finding its way to
for-each without having its current value extracted (by 'value-now').
It might just be a matter of adding a call to 'value-now' somewhere in
fluxus.  If it turns out to be something more complicated than that,
let me know and I'll take a closer look.


> Sorry it's taking me so long to get all this! Hopefully I should be able
> to offer some additional documentation in return for all the help.
> The source is here: http://www.pawfal.org/flotsam/frisbee/rocket.scm
> Let me know if you can't see it - it seems to randomly ask for a
> password.
> cheers,
> dave

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