DEFINITION MODULE FOR "C" GError ;

(*
   m2-GTK4 - GError: the GLib error value.  Mapped onto
   <glib/gerror.h>.

   The C struct is public, so it is modelled directly.  Most C APIs
   take a GError ** out-parameter; in Modula-2 declare a VAR of type
   GError and pass its address:

      VAR err: GError;
      ...
      err := NIL;
      ok := g_file_delete(file, NIL, ADR(err));
      IF err # NIL THEN ... END;

   Use GtkUtils.ErrorMessage() to read the message and
   GtkUtils.ClearError() (or g_error_free) to release it.
*)

FROM SYSTEM IMPORT ADDRESS;

EXPORT UNQUALIFIED
   GError, GErrorRec,
   g_error_free, g_error_copy, g_error_matches, g_clear_error;


TYPE
   GError = POINTER TO GErrorRec;
   (* struct _GError { GQuark domain; gint code; gchar *message; }; *)
   GErrorRec = RECORD
      domain: CARDINAL;
      code: INTEGER;
      message: ADDRESS;
   END;

(* void g_error_free(GError *error) *)
PROCEDURE g_error_free (error: GError);

(* GError *g_error_copy(const GError *error) *)
PROCEDURE g_error_copy (error: GError) : GError;

(* gboolean g_error_matches(const GError *error, GQuark domain, gint code) *)
PROCEDURE g_error_matches (error: GError; domain: CARDINAL;
                           code: INTEGER) : [ INTEGER ];

(* void g_clear_error(GError **err) *)
PROCEDURE g_clear_error (VAR err: GError);

END GError.