Example #1
0
func Thompson(program InstSlice, text []byte) bool {
	var cqueue, nqueue *queue.Queue = queue.New(), queue.New()
	cqueue.Push(0)
	for tc := 0; tc <= len(text); tc++ {
		for !cqueue.Empty() {
			pc := cqueue.Pop()
			inst := program[pc]
			switch inst.Op {
			case CHAR:
				if int(tc) < len(text) && text[tc] == byte(inst.X) {
					nqueue.Push(pc + 1)
				}
			case MATCH:
				if tc == len(text) {
					return true
				}
			case JMP:
				cqueue.Push(inst.X)
			case SPLIT:
				cqueue.Push(inst.X)
				cqueue.Push(inst.Y)
			}
		}
		cqueue, nqueue = nqueue, cqueue
	}
	return false
}
Example #2
0
func LexerEngine(program InstSlice, text []byte) (chan bool, chan Match) {
	matches := make(chan Match)
	success := make(chan bool)
	go func() {
		var cqueue, nqueue *queue.Queue = queue.New(), queue.New()
		match_pc := -1
		match_tc := -1
		start_tc := 0
		cqueue.Push(0)
		for tc := 0; tc <= len(text); tc++ {
			for !cqueue.Empty() {
				pc := cqueue.Pop()
				inst := program[pc]
				switch inst.Op {
				case CHAR:
					if int(tc) < len(text) && text[tc] == byte(inst.X) {
						nqueue.Push(pc + 1)
					}
				case MATCH:
					if match_tc < tc {
						match_pc = int(pc)
						match_tc = tc
					} else if match_pc > int(pc) {
						match_pc = int(pc)
						match_tc = tc
					}
				case JMP:
					cqueue.Push(inst.X)
				case SPLIT:
					cqueue.Push(inst.X)
					cqueue.Push(inst.Y)
				}
			}
			cqueue, nqueue = nqueue, cqueue
			if cqueue.Empty() && match_pc != -1 {
				matches <- Match{text[start_tc:match_tc], match_pc}
				cqueue.Push(0)
				start_tc = tc
				match_pc = -1
				tc -= 1
			}
		}
		close(matches)
		if match_tc == len(text) {
			success <- true
		} else {
			success <- false
		}
		close(success)
	}()
	return success, matches
}