Re: setf.scm

[Per Bothner <bothner@cygnus.com>]

Chris.Bitmead@misys.com.au writes:
> I'm just thinking from a CLOS point of view now...
> Shouldn't [(set! (PROC ARGS ...) RHS)] expand to something like...
> (setter RHS PROC ARGS ...)    ? [rather than ((setter PROC) RHS ARGS ...)]
> Because if setter is a CLOS method, it would most likely want to dispatch 
> on the type of ARGS, especially ARG1. Therefore shouldn't it be one of the 
> arguments to allow dispatch? It also seems cleaner if the ARGS and PROC are 
> kept together. Procedure and arguments evaluated the same way and all that.

Perhaps, but I think expanding to ((setter PROC) RHS ARGS ...) is simpler.
Note there is nothing to prevent (setter PROC) from evaluating
to a generic function, which dispatches on RHS+ARGS to select the
correct method.  So you have the flexibility you want, but separate
into two parts: (1) mapping from PRC to its setter (2) applying the
setter, which may involve multi-method dispatch [assuming you have
multi-method dispatch, of course].

	--Per Bothner
Cygnus Solutions     bothner@cygnus.com     http://www.cygnus.com/~bothner