unofficial mirror of guile-user@gnu.org 
 help / color / mirror / Atom feed
From: Neil Jerram <neil@ossau.uklinux.net>
Cc: guile-user@gnu.org
Subject: Re: equivalent of "this" in goops?
Date: Wed, 16 Feb 2005 23:43:19 +0000	[thread overview]
Message-ID: <4213DA97.5000700@ossau.uklinux.net> (raw)
In-Reply-To: <87sm3wt877.fsf@ivanova.rotty.yi.org>

Andreas Rottmann wrote:
> Greg Troxel <gdt@ir.bbn.com> writes:
> 
>>In a class representing a node, I want to have a slot with an
>>init-thunk, [...] So, I'd like to pass 'this' in c++ terms, and I don't see how to do
>>that from reading goops.info.
> 
> FWICT (not being a GOOPS expert), this is not possible without
> extending GOOPS: the init-thunk of a slot is specified at class
> creation time, and the earliest time "this" is avaiable is in the
> "initialize" generic. However, since the init-thunk is called at
> initialization time, "this" would be available at the time it is run,
> but there is no way to pass it, since the init-thunk, is, well, a
> thunk ;). I could imagine a init-function (name to be argued), which
> gets passed all arguments from "initialize" could be a useful
> extension.

Absolutely right.  Your best bet at this point is to customize the 
initialize method for the class:

(define-method (initialize (this <node>) initargs)
   (next-method)
   (slot-set this 'name-of-slot-with-init-thunk
             (init-function this)))

(It's probably also possible to use the MOP to support #:init-proc as a 
new slot option, but that would require more thought.)

Regards,
	Neil


_______________________________________________
Guile-user mailing list
Guile-user@gnu.org
http://lists.gnu.org/mailman/listinfo/guile-user


  reply	other threads:[~2005-02-16 23:43 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-02-16 21:35 equivalent of "this" in goops? Greg Troxel
2005-02-16 23:07 ` Andreas Rottmann
2005-02-16 23:43   ` Neil Jerram [this message]
2005-02-18 17:42     ` Greg Troxel

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/guile/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4213DA97.5000700@ossau.uklinux.net \
    --to=neil@ossau.uklinux.net \
    --cc=guile-user@gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).