void (*var_changed) (struct dictionary *, int, unsigned int, const struct variable *, void *);
void (*weight_changed) (struct dictionary *, int, void *);
void (*filter_changed) (struct dictionary *, int, void *);
void (*var_changed) (struct dictionary *, int, unsigned int, const struct variable *, void *);
void (*weight_changed) (struct dictionary *, int, void *);
void (*filter_changed) (struct dictionary *, int, void *);