+ int (*f_forward)(RSET ct, RSFD rfd, void *buf, int *term_index,
+ int (*cmpfunc)(const void *p1, const void *p2),
+ const void *untilbuf);
+ void (*f_pos)(RSFD rfd, int *current, int *total);
+ /* FIXME - Should be 64-bit ints !*/
+ /* returns -1,-1 if pos function not implemented for this type */