An Example of Gauche Extension Module

example.c

#include "example.h"

ScmClass* ExampleClass;

static void example_class_print (ScmObj obj, ScmPort* out, ScmWriteContext* ctx)
{
  struct example* e = EXAMPLE_UNBOX(obj);
 
  Scm_Printf(out, "#<example-class \"%p\">", e);
}

static void example_class_cleanup (ScmObj obj)
{
  struct example* e = EXAMPLE_UNBOX(obj);
  free(e);
}

/*
 * Module initialization function.
 */
extern void Scm_Init_examplelib (ScmModule*);
 
void Scm_Init_example (void)
{
  ScmModule *mod;

  /* Register this DSO to Gauche */
  SCM_INIT_EXTENSION(example);

  /* Create the module if it doesn't exist yet. */
  mod = SCM_MODULE(SCM_FIND_MODULE ("example", TRUE));

  ExampleClass =
    Scm_MakeForeignPointerClass(mod,
                                "<example-class>",
                                example_class_print,
                                example_class_cleanup,
                                SCM_FOREIGN_POINTER_KEEP_IDENTITY | SCM_FOREIGN_POINTER_MAP_NULL);

  /* Register stub-generated procedures */
  Scm_Init_examplelib (mod);
}

example.h

/* Prologue */
#ifndef GAUCHE_EXAMPLE_H
#define GAUCHE_EXAMPLE_H

#include <gauche.h>
#include <gauche/extend.h>

SCM_DECL_BEGIN

struct example {
  int x;
};

extern ScmClass *ExampleClass;
#define EXAMPLE_P(obj)      SCM_XTYPEP (obj, ExampleClass)
#define EXAMPLE_UNBOX(obj)  SCM_FOREIGN_POINTER_REF (struct example*, obj)
#define EXAMPLE_BOX(obj)    Scm_MakeForeignPointer (ExampleClass, obj)

/* Epilogue */
SCM_DECL_END

#endif  /* GAUCHE_EXAMPLE_H */

example.scm

(define-module example
  (export <example-class>
          ))
(select-module example)

;; Loads extension
(dynamic-load "example")

examplelib.stub

"
#include \"example.h\"
"

(define-type <example-class> "struct example*" "example class" "EXAMPLE_P" "EXAMPLE_UNBOX" "EXAMPLE_BOX")

;; Local variables:
;; mode: scheme
;; end: