> > Is it possible to define-syntax "define-struct" ?

> Do you mean the "define-struct" like the one described in the
> following URL?
>  http://pre.plt-scheme.org/docs/html/beginning/define-struct.html

> To do that, you need two things:
> 1. A suitable representation for the struct types.
> 2. A macro system.

> > Mit scheme don't have mzscheme type define-struct.

> I don't know much about MIT Scheme but here is the general idea.

> If your Scheme system provides the means for creating new record/
> struct types, then you can use that as a basis for the representation
> of your structs.  Otherwise, tagged vectors (i.e. vectors where the
> first element is a descriptor for the struct type) may work ok.

> If your want "define-struct" to construct the constructor, predicate,
> accessors and setters names for you, then you need a macro system that
> has that capability.  A syntax-case system would work nicely.  If all
> you have is syntax-rules, then you need to specify the names of all
> the procedures in the define-struct form.  This would make define-
> struct forms look something like:

> (define-struct foo make-foo foo?
>   (foo-bar set-foo-bar!)
>   (foo-baz set-foo-baz!)
>   ...)

> instead of the much shorter form:

> (define-struct foo (bar baz ...))

> Does this answer your question?  Let us know if you have any troubles.

> Aziz,,,