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From: Olivier Dion via General Guile related discussions <guile-user@gnu.org>
To: paul <paul@inktvis.org>, guile-user@gnu.org
Subject: Re: Trouble creating SRFI-9 Record in C
Date: Fri, 10 Sep 2021 23:59:27 -0400	[thread overview]
Message-ID: <87wnnng3ts.fsf@laura> (raw)
In-Reply-To: <m235qbalsh.fsf@inktvis.org>

On Sat, 11 Sep 2021, paul <paul@inktvis.org> wrote:

> In Guile land, that works great.  Now, i want to create a foo in C 
> and pass it to a function in the Guile script.  I do something 
> like the following:
>
> ```
> scm_c_primitive_load("foo.scm");
> scm_call_5(scm_variable_ref(scm_c_lookup("make-foo")),
>            scm_from_utf8_string("blah"),
>            scm_from_int32(Int32(42)))
> ```
>
> However, this results in an error:
>
> guile: uncaught exception:
> Wrong type to apply: #<syntax-transformer make-foo>

Seems like `make-foo` is a syntax-transformer and not a procedure.  You
can not call a syntax-transformer.  I don't think you can do much with a
syntax-transformer in C.

>
> I've tried with and without (define-module foo) at the top of the 
> file, that doesn't seem to make a difference.  I've been able to 
> work around the issue by defining a wrapper (define (foo-prime a 
> b) (make-foo a b)) and using that in C as shown above, but that 
> feels ugly.  I'm probably missing something obvious, but trawling 
> the mailing list didn't turn up anything i could understand.

By making a wrapper, you're effectively creating a procedure that can
use the `make-foo` syntax because it's in Scheme and it's solved a
expansion time.

-- 
Olivier Dion
Polymtl



  reply	other threads:[~2021-09-11  3:59 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-11  2:27 Trouble creating SRFI-9 Record in C paul
2021-09-11  3:59 ` Olivier Dion via General Guile related discussions [this message]
2021-09-11 13:30 ` Matt Wette
2021-09-11 23:42   ` paul

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