<div class="gmail_quote">On Wed, Sep 15, 2010 at 15:19, Robby Findler <<a href="mailto:robby@eecs.northwestern.edu">robby@eecs.northwestern.edu</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> The class exists at runtime, not at compile time, so you can't just take an identifier like that and get the names of the methods back. (This is a fundamental difference between our class system and ones like in Java. See <a href="http://www.eecs.northwestern.edu/%7Erobby/pubs/papers/aplas2006-fff.pdf" target="_blank">http://www.eecs.northwestern.edu/~robby/pubs/papers/aplas2006-fff.pdf</a> for more info about the high level properties of the class system.) At least not with the current class system. You can, however, define a macro, something like: (define-class <name> <class-expr>) and then have define-class inspect the class-expr to find the method names (note you'll have to use local-expand to make this work) and put that information into <name> at compile time. </blockquote><div> Or maybe I can define a% in a separate module and require it for-syntax either? So here is where I am right now: #lang racket (require "a.rkt" (for-syntax "a.rkt")) (define-syntax-rule (define-singleton-sender fun obj meth) (define-syntax-rule (fun args (... ...)) (send (obj) meth args (... ...)))) (define-syntax (class->singleton stx) (syntax-case stx () [(_ cl obj) (with-syntax ([(name ...) (interface->method-names (class->interface a%))]) ; *** #'(begin (define-singleton-sender name obj name) ...))])) (define current-a (make-parameter (new a% [a 3]))) (class->singleton a% current-a) This works for class a%, but only for this one, as I don't know how to pass a% as an argument to the macro (note the a% on line ***). How can I do that? </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> hth, Robby <div><div></div><div class="h5"> On Wed, Sep 15, 2010 at 7:50 AM, Laurent <<a href="mailto:laurent.orseau@gmail.com">laurent.orseau@gmail.com</a>> wrote: > Dear all, > > Apparently I still don't have my macro writing licence. > I'm stuck somewhere around syntax-case and with-syntax. > > Here is my problem. > Suppose something like this: > > (define-syntax (class->singleton stx) > (syntax-case stx () > [(_ cl) > (with-syntax ([(name ...) > (interface->method-names (class->interface #'cl))]) ; > *** > #'(begin (define-something name) > ...))])) > > (class->singleton a%) > > On line *** I want to match (name ...) with the list of method-names of > the given class (here a%). > Obviously, this is wrong, since #'cl is just a syntaxed identifier IIUC, > but should be the class itself. > datum->syntax and syntax->datum don't help either, so what should I do? > Any hint (even an RTFM link) would be appreciated. > > Thanks, > Laurent > > > </div></div><div><div></div><div class="h5">> _________________________________________________ > For list-related administrative tasks: > <a href="http://lists.racket-lang.org/listinfo/users" target="_blank">http://lists.racket-lang.org/listinfo/users</a> > </div></div></blockquote></div>