}

// onePassNext selects the next actionable state of the prog, based on the input character.
// It should only be called when i.Op == InstAlt or InstAltMatch, and from the one-pass machine.
// One of the alternates may ultimately lead without input to end of line. If the instruction
// is InstAltMatch the path to the InstMatch is in i.Out, the normal node in i.Next.
func onePassNext(i *onePassInst, r rune) uint32 {
	next := i.MatchRunePos(r)

}

// An InstOp is an instruction opcode.
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",

	d.t = nil
	d.pc = pc
	q.sparse[pc] = uint32(j)

	i := &m.p.Inst[pc]
	switch i.Op {
	default:
		panic("unhandled")
	case syntax.InstFail:
		// nothing
	case syntax.InstAlt, syntax.InstAltMatch:
		t = m.add(q, i.Out, pos, cap, cond, t)
		pc = i.Arg
		goto Again
	case syntax.InstEmptyWidth:
		if cond.match(syntax.EmptyOp(i.Arg)) {
			pc = i.Out
			goto Again
		}
	case syntax.InstNop:

				arg = false
				pc = inst.Arg
				goto CheckAndLoop
			} else {
				b.push(re, pc, pos, true)
				pc = inst.Out
				goto CheckAndLoop
			}

		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.

		{"FoldCase", Const, 0},
		{"Inst", Type, 0},
		{"Inst.Arg", Field, 0},
		{"Inst.Op", Field, 0},
		{"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},

pkg regexp/syntax, const ErrMissingRepeatArgument ErrorCode
pkg regexp/syntax, const ErrTrailingBackslash ErrorCode
pkg regexp/syntax, const FoldCase Flags
pkg regexp/syntax, const InstAlt InstOp
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 ErrUnexpectedParen = "unexpected )"
pkg regexp/syntax, const ErrUnexpectedParen ErrorCode
pkg regexp/syntax, const FoldCase = 1
pkg regexp/syntax, const InstAlt = 0
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