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Re: Ellipses

This page is part of the web mail archives of SRFI 93 from before July 7th, 2015. The new archives for SRFI 93 contain all messages, not just those from before July 7th, 2015.



On 6/24/06, Jens Axel Søgaard <jensaxel@xxxxxxxxxxxx> wrote:

The only place (... ...) is needed is in macro-defining macros, which
aren't too common. A search through the PLT code base for (... ...)
versus a search for ... gives a good impression of how uncommon it is.
In my opinion it would therefore be annoying to the specify the ellipsis
in the "boiler plate" every time I need to define a standard macro.

Furthermore with-syntax lets you choose your own ellipsis, when
you need to define a macro-defining macro:

   (with-syntax ((::: #'(... ...))
     <use ::: here>)

I think it's a little nicer to write something like

(define-syntax syntax-case
   (syntax-case-macro
      (lambda (stx)
         (parametrized-syntax-case stx *** ()
            ((syntax-case name vars body ***)
              #`(parametrized-syntax-case #,(datum->syntax stx '...)
vars body ***))))))

Disclaimer:  I don't know syntax-case well enough to be certain of the
above code, but I think it should be about right.

David Feuer