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Re: global variables & data tags (a la X-Windows callbacks)

RB> Are there any plans to add a "tag" argument to gh_new_procedureX_Y() /
RB> gh_new_procedure() / scm_make_gsubr() ?

RB> The motivation is, as was designed in X-Windows, to pass a "data tag"
RB> which can be passed to the procedure (a "callback" in X-Windows jargon).
RB> This mechanism allows me to avoid the use of global variables -- the
RB> relevant data can be passed along to the procedure.

I don't understand what you would need this for. In X, this is used
since you don't have closures in C which you basically need for

In Scheme on the other hand this is easy to do by wrapping a function
in a let-form. Since you are defining new Scheme procedures, you are
not limited to use C, right?

Could you explain the possible applications?

Lars Arvestad               Dept. of Numerical Analysis and Computing Science
                       Royal Institute of Technology (KTH), Stockholm, Sweden