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new module directive? [was: Three real-life questions]

From: Andreas Rottmann
Subject: new module directive? [was: Three real-life questions]
Date: Tue, 13 Apr 2004 18:33:33 +0200
User-agent: Gnus/5.1002 (Gnus v5.10.2) Emacs/21.3 (gnu/linux)

Andy Wingo <address@hidden> writes:

> Hi Michael,
> On Tue, 2004-04-06 at 13:01, Michael Burschik wrote:
>> 1. How should one export, or re-export modified generic functions?
>>  Using :export seems to work as expected, although guile complains
>>  about the use of deprecated features. Using :re-export gets rid of the
>>  complaints, but does not seem to be documented in the guile manual. So
>>  what is the correct way to handle generic functions in modules?
> If a module that you use supplies a binding, and you want that binding
> to be available for users of your module, you must re-export it. This
> applies to generics as well as other bindings. Lack of documentation on
> this is a bug, though!
The hairy thing is when you want to override (extend) a non-generic
with a generic. #:re-export won't work in this case and #:export gives
a warning. Example code:

;; export-test.scm

(define-module (export-test)
  #:use-module (oop goops)
  #:export (quit))

(define quit (ensure-generic quit))

(define-class <mainloop>)

(define-method (quit (loop <mainloop>))
  ;; some code here

Then, the extended quit works as expected:

ivanova:~/tmp/test% guile
guile> (use-modules (export-test) (oop goops))
Using `export' to re-export imported bindings is deprecated.  Use `re-export' 
(You just re-exported `quit' from `(export-test)'.)
guile> (quit (make <mainloop>))
#<<mainloop> 80891a0>
guile> (quit 66)
ivanova:~/tmp/test% echo $?

I'd really like to see an #:override or somesuch module option that
doesn't warn in this case...

Andreas Rottmann         | address@hidden      | address@hidden | address@hidden      | GnuPG Key:
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