InstEmptyWidth
	InstMatch
	InstFail
	InstNop
	InstRune
	InstRune1
	InstRuneAny
	InstRuneAnyNotNL
)

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

func (i InstOp) String() string {
	if uint(i) >= uint(len(instOpNames)) {
		return ""

	}
	if i.Op == syntax.InstAltMatch {
		return i.Out
	}
	return 0
}

func iop(i *syntax.Inst) syntax.InstOp {
	op := i.Op
	switch op {
	case syntax.InstRune1, syntax.InstRuneAny, syntax.InstRuneAnyNotNL:
		op = syntax.InstRune
	}
	return op
}

// Sparse Array implementation is used as a queueOnePass.
type queueOnePass struct {
	sparse          []uint32
	dense           []uint32

			}

		case syntax.InstAltMatch:
			// One opcode consumes runes; the other leads to match.
			switch re.prog.Inst[inst.Out].Op {
			case syntax.InstRune, syntax.InstRune1, syntax.InstRuneAny, syntax.InstRuneAnyNotNL:
				// inst.Arg is the match.
				b.push(re, inst.Arg, pos, false)
				pc = inst.Arg
				pos = b.end
				goto CheckAndLoop
			}
			// inst.Out is the match - non-greedy

		{"InstFail", Const, 0},
		{"InstMatch", Const, 0},
		{"InstNop", Const, 0},
		{"InstOp", Type, 0},
		{"InstRune", Const, 0},
		{"InstRune1", Const, 0},
		{"InstRuneAny", Const, 0},
		{"InstRuneAnyNotNL", Const, 0},
		{"IsWordChar", Func, 0},
		{"Literal", Const, 0},
		{"MatchNL", Const, 0},
		{"NonGreedy", Const, 0},
		{"OneLine", Const, 0},
		{"Op", Type, 0},
		{"OpAlternate", Const, 0},