Re: [clisp-list] macros for CLISP

[Michael G. <mgr...@ma...>]

On Tue, 9 Mar 2004, Pascal J.Bourguignon wrote:

> I  don't know but  your code  looks quite  complicated.  Let  the lisp
> reader do its work, and avoid concatenating strings like that!

Yeah, I'd have to agree with you there. The code in question is
essentially straight out of the Matlisp distribution. This was my first
exposure to Lisp macro characters (I like it!), and after getting the hang
of it a bit, I ended up re-writing the entire thing in a much simpler way
that works in CLISP, CMUCL and others.

> > (return-from parse-matrix-expression-1
> >                 (list 'make-matrix-from-reader
> >                       (list 'quote (list n m))
> >                       :initial-contents `(list ,@matrix-1)))))
>
> Macro characters are not macros!  You don't return an expression to be
> evaluated, you return the data item read.

Are you sure? I just finished writing a macro character that tried to
return a list, but which failed with an eval error -- so I ended up
inserting a quote in front of it all.

Or maybe I'm misunderstanding you.

> The  following implementation works  as well  in clisp  as in  sbcl or
> cmucl. You  would have to  add computing of  element type. It  is much
> less complicated  to compute the  dimension while reading  the matrix,
> otherwise the  list where I  store the data  could be mixed  with data
> lists.

Thanks! I look forward to studying it.

I must say, the more Lisp I learn, the more I like it and can't imagine
how I used other languages. I suppose this is the general consensus :)