25.1.6.6 C functions

C function types are introduced by the <function-type> clause:

<function-type> → (function <ident> (<ident>*))

Let us suppose the array type declaration:

(type fun (function res (arg*)) ...)

Bigloo creates the following functions:

• A type checker:

  (fun?::bool obj::obj)

  This function returns #t if the argument obj is of type fun and #f otherwise.

• An equality checker:

  (=fun*?::bool ::fun* ::fun*)

  This function returns #t if and only if its arguments are equal.

• Caller:

  (fun-call::res f::fun a::ta ...)

  This function invokes f with the arguments a … an.

Suppose we have to use in Scheme the following C variable:

double (*convert)(char *);

It can be done as in:

(module foo 
   (extern
    (type *string->double
          (function double (string)) 
                    "double (*)(char *)")
    (macro cv::*string->double "convert")))

(print (*string->double-call cv "3.14"))