Coalton and cffi

[cerk]

I want to wrap a cffi:defctype as a Coalton type:

(in-package #:cffi-test)

(cffi:defctype my-c-int :int)

(named-readtables:in-readtable coalton:coalton)

(coalton-toplevel
  (repr :native my-c-int)
  (define-type MyCInt)

  (declare add-one (MyCInt -> MyCInt))
  (define (add-one x)
    (lisp MyCInt (x) (cl:+ x 1))))

When I execute:

(cffi-test::add-one 1)

I get:

unknown type specifier: CFFI-TEST::MY-C-INT
   [Condition of type SIMPLE-ERROR]

I am assuming that Coalton doesn't play well with cffi:defctype. Is there a way to achieve what I want to do?

Thank you!

[stylewarning]

This defines a new CFFI type to be used with the CFFI defining functions. It doesn't define a new Lisp type and so REPR won't work.

C data can't be freely passed in and around Lisp functions.

[cerk]

Thank you for the explanation.

If anyone is curious, I made things work by using cffi:define-foreign-type with corresponding functions cffi:define-parse-method, cffi:translate-from-foreign and cffi:translate-to-foreign to convert back and forth from lisp values to cffi values. I created a deftype compatible with the lisp values I was interested in and then used repr :native with this deftype. There is code that transforms coalton values to lisp values to cffi values and there is code that transforms cffi values to lisp values to coalton values.