Re: Trouble creating SRFI-9 Record in C

[Matt Wette <matt.wette@gmail.com>]

maybe add

(define (make-foo-x a b) (make-foo a b))

then call make-foo-x (or reverse names)

On 9/10/21 7:27 PM, paul wrote:
> Good day guile-users,
>
> I am having a struggle with SRFI-9 records.  They look very 
> convenient, so i'd like to use them in my Guile scripts.  However, i'm 
> not sure how to correctly construct them from C-land.  I have 
> something like the following:
>
> ```
> (define-record-type <foo>
>  (make-foo a b)
>  foo?
>  (a foo-a)
>  (b foo-b))
> ```
>
> 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>
>
> 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.
>
> Does anyone see what i'm doing wrong, or can i simply not use SRFI-9 
> records in this way?
>
> Thanks, 🙌
> p.
>