[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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.

David Feuer skrev:
I think Petrofsky's suggestion for handling ellipses (SRFI-46) is far
cleaner that the one in the SRFI-93 draft.  For syntax-rules macros, I
would recommend adopting the SRFI-46 method, or something very similar
to it.  As well as being easier to understand, I believe that the
current proposal would be expressible in Petrofsky's syntax, but that
the converse does not hold.  For syntax-case macros, I think we should
take the opportunity to go all the way with Petrofsky's idea, and make
the ellipsis identifier a required argument to SYNTAX-CASE.

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>)

Jens Axel Søgaard