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:

			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},