OPSHIFT
assert(opnd < 1<<OPSHIFT);
assert(value < 1<<OPSHIFT);
#define OOR2 (17L<<OPSHIFT) /* | pt. 2 fwd to OOR2 or O_CH */
#define O_CH (18L<<OPSHIFT) /* end choice back to OOR1 */
#define OBOW (19L<<OPSHIFT) /* begin word - */
#define OEOW (20L<<OPSHIFT) /* end word - */
#define OBOS (21L<<OPSHIFT) /* begin subj. - */
#define OEOS (22L<<OPSHIFT) /* end subj. - */
#define OWBND (23L<<OPSHIFT) /* word bound - */
#define ONWBND (24L<<OPSHIFT) /* not bound - */
#define OEND (1L<<OPSHIFT) /* endmarker - */
#define OCHAR (2L<<OPSHIFT) /* character wide character */
#define OBOL (3L<<OPSHIFT) /* left anchor - */
#define OEOL (4L<<OPSHIFT) /* right anchor - */
#define OANY (5L<<OPSHIFT) /* . - */
#define OANYOF (6L<<OPSHIFT) /* [...] set number */
#define OBACK_ (7L<<OPSHIFT) /* begin \d paren number */
#define O_BACK (8L<<OPSHIFT) /* end \d paren number */
#define OPLUS_ (9L<<OPSHIFT) /* + prefix fwd to suffix */
#define O_PLUS (10L<<OPSHIFT) /* + suffix back to prefix */
#define OQUEST_ (11L<<OPSHIFT) /* ? prefix fwd to suffix */
#define O_QUEST (12L<<OPSHIFT) /* ? suffix back to prefix */
#define OLPAREN (13L<<OPSHIFT) /* ( fwd to ) */
#define ORPAREN (14L<<OPSHIFT) /* ) back to ( */
#define OCH_ (15L<<OPSHIFT) /* begin choice fwd to OOR2 */
#define OOR1 (16L<<OPSHIFT) /* | pt. 1 back to OOR1 or OCH_ */