[plt-scheme] picture language predicates?

I have a simple visualisation package that composes pictures out of
circles, dots, etc. Code is here:

http://github.com/noelwelsh/numeric/tree/9a06001f32e1a234dff96cd5427670baf9629af5/bonfire

It doesn't support graphical snips like the picture language, but you
can render to a MrEd window. It might be of use.

N.

On Mon, Sep 7, 2009 at 9:58 AM, Wolfgang De Meuter<wdmeuter at vub.ac.be> wrote:
> Hello
>
> I'm trying to use the picture language to create some courseware. Are there
> any predicates allowing me to test whether a picture is a circle,
> rectangle,... If not... any other hacks that allow me to know what the
> 'type' of a picture is? I was thinking about writing procedures for
> calculating circumferences for various pictures.
>
> Regards
> Wolf
>
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