type InstOp uint8

const (
	InstAlt InstOp = iota
	InstAltMatch
	InstCapture
	InstEmptyWidth
	InstMatch
	InstFail
	InstNop
	InstRune
	InstRune1
	InstRuneAny
	InstRuneAnyNotNL
)

var instOpNames = []string{
	"InstAlt",
	"InstAltMatch",
	"InstCapture",
	"InstEmptyWidth",
	"InstMatch",
	"InstFail",
	"InstNop",
	"InstRune",
	"InstRune1",
	"InstRuneAny",
	"InstRuneAnyNotNL",
}

		return nil
	}
	// every instruction leading to InstMatch must be EmptyEndText
	for _, inst := range prog.Inst {
		opOut := prog.Inst[inst.Out].Op
		switch inst.Op {
		default:
			if opOut == syntax.InstMatch {
				return nil
			}
		case syntax.InstAlt, syntax.InstAltMatch:
			if opOut == syntax.InstMatch || prog.Inst[inst.Arg].Op == syntax.InstMatch {
				return nil
			}
		case syntax.InstEmptyWidth:

			m.pool = append(m.pool, t)
			continue
		}
		i := t.inst
		add := false
		switch i.Op {
		default:
			panic("bad inst")

		case syntax.InstMatch:
			if len(t.cap) > 0 && (!longest || !m.matched || m.matchcap[1] < pos) {
				t.cap[1] = pos
				copy(m.matchcap, t.cap)
			}
			if !longest {
				// First-match mode: cut off all lower-priority threads.

// The regexp should have been simplified already (returned from re.Simplify).
func Compile(re *Regexp) (*Prog, error) {
	var c compiler
	c.init()
	f := c.compile(re)
	f.out.patch(c.p, c.inst(InstMatch).i)
	c.p.Start = int(f.i)
	return c.p, nil
}

func (c *compiler) init() {
	c.p = new(Prog)
	c.p.NumCap = 2 // implicit ( and ) for whole match $0
	c.inst(InstFail)
}

			if !flag.match(syntax.EmptyOp(inst.Arg)) {
				continue
			}
			pc = inst.Out
			goto CheckAndLoop

		case syntax.InstNop:
			pc = inst.Out
			goto CheckAndLoop

		case syntax.InstMatch:
			// We found a match. If the caller doesn't care
			// where the match is, no point going further.
			if len(b.cap) == 0 {
				return true
			}

			// Record best match so far.

		{"Inst.Out", Field, 0},
		{"Inst.Rune", Field, 0},
		{"InstAlt", Const, 0},
		{"InstAltMatch", Const, 0},
		{"InstCapture", Const, 0},
		{"InstEmptyWidth", Const, 0},
		{"InstFail", Const, 0},
		{"InstMatch", Const, 0},
		{"InstNop", Const, 0},
		{"InstOp", Type, 0},
		{"InstRune", Const, 0},
		{"InstRune1", Const, 0},
		{"InstRuneAny", Const, 0},
		{"InstRuneAnyNotNL", Const, 0},

pkg regexp/syntax, const InstAltMatch InstOp
pkg regexp/syntax, const InstCapture InstOp
pkg regexp/syntax, const InstEmptyWidth InstOp
pkg regexp/syntax, const InstFail InstOp
pkg regexp/syntax, const InstMatch InstOp
pkg regexp/syntax, const InstNop InstOp
pkg regexp/syntax, const InstRune InstOp
pkg regexp/syntax, const InstRune1 InstOp
pkg regexp/syntax, const InstRuneAny InstOp

pkg regexp/syntax, const InstAltMatch = 1
pkg regexp/syntax, const InstCapture = 2
pkg regexp/syntax, const InstEmptyWidth = 3
pkg regexp/syntax, const InstFail = 5
pkg regexp/syntax, const InstMatch = 4
pkg regexp/syntax, const InstNop = 6
pkg regexp/syntax, const InstRune = 7
pkg regexp/syntax, const InstRune1 = 8
pkg regexp/syntax, const InstRuneAny = 9
pkg regexp/syntax, const InstRuneAnyNotNL = 10