Re: [EXT] GOOPS class printing

["Thompson, David" <dthompson2@worcester.edu>]

Hi Mike,

On Wed, Feb 23, 2022 at 4:44 PM Mike Gran <spk121@yahoo.com> wrote:
>
> Hello all-
>
> If I define a GOOPS class like so...
>
>    (use-modules (oop goops))
>    (define-class <foo> ())
>    <foo>
>
> When it is printed, it has a long hex string in it
>
>     $2 = #<<class> <foo> 7fa3d9a5bc80>
>
> Is there a way to change how a class prints itself so that
> it does not have a hex string?  So that it is just
>
>    #<<class> <foo>>
>
> or something similar?

GOOPS turns several procedures into methods, such as 'write'.  I think
I've defined special write methods in the past for this purpose.  Here
is a basic and silly example:

scheme@(guile-user)> (define-class <foo> ())
scheme@(guile-user)> (make <foo>)
$33 = #<<foo> 55ddef3b0680>
scheme@(guile-user)> (define-method (write (foo <foo>) port)
                       (display "hello" port))
scheme@(guile-user)> (make <foo>)
$34 = hello

Hope that helps,

- Dave