Re: Trouble creating SRFI-9 Record in C

[paul <paul@inktvis.org>]

Hey Matt,

Yeah that was exactly my workaround 🙂 I was wondering whether i could use the syntax transformer more "directly" from C, or something like that. 

Thanks,
paul

> On 11 Sep 2021, at 23:31, Matt Wette <matt.wette@gmail.com> wrote:
> 
> 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.
>> 
> 
>