contrib/flex/nfa.c

292  *   new = link_machines( first, last );
294  *     new    - a machine constructed by connecting first to last
295  *     first  - the machine whose successor is to be last
296  *     last   - the machine whose predecessor is to be first
298  * note: this routine concatenates the machine first with the machine
299  *  last to produce a machine new which will pattern-match first first
304 int     link_machines (first, last)
305      int     first, last;
307 	if (first == NIL)
311 		return first;
314 		mkxtion (finalst[first], last);
315 		finalst[first] = finalst[last];
316 		lastst[first] = MAX (lastst[first], lastst[last]);
317 		firstst[first] = MIN (firstst[first], firstst[last]);
319 		return first;
328  * The "beginning" states are the epsilon closure of the first state
363  *   branch = mkbranch( first, second );
365  *     branch - a machine which matches either first's pattern or second's
366  *     first, second - machines whose patterns are to be or'ed (the | operator)
368  * Note that first and second are NEITHER destroyed by the operation.  Also,
373 int     mkbranch (first, second)
374      int     first, second;
378 	if (first == NO_TRANSITION)
382 		return first;
386 	mkxtion (eps, first);
449  *   new = mkor( first, second );
451  *     new - a machine which matches either first's pattern or second's
452  *     first, second - machines whose patterns are to be or'ed (the | operator)
454  * note that first and second are both destroyed by the operation
459 int     mkor (first, second)
460      int     first, second;
464 	if (first == NIL)
468 		return first;
471 		/* See comment in mkopt() about why we can't use the first
472 		 * state of "first" or "second" if they satisfy "FREE_EPSILON".
476 		first = link_machines (eps, first);
478 		mkxtion (first, second);
480 		if (SUPER_FREE_EPSILON (finalst[first]) &&
481 		    accptnum[finalst[first]] == NIL) {
482 			orend = finalst[first];
489 			mkxtion (finalst[first], orend);
495 			first = link_machines (first, eps);
496 			orend = finalst[first];
502 	finalst[first] = orend;
503 	return first;
640 		 * first time.