// be true in any match. It returns ^EmptyOp(0) if no matches are possible.
func (p *Prog) StartCond() EmptyOp {
	var flag EmptyOp
	pc := uint32(p.Start)
	i := &p.Inst[pc]
Loop:
	for {
		switch i.Op {
		case InstEmptyWidth:
			flag |= EmptyOp(i.Arg)
		case InstFail:
			return ^EmptyOp(0)
		case InstCapture, InstNop:
			// skip
		default:
			break Loop
		}

		m.pool = m.pool[:n-1]
	} else {
		t = new(thread)
		t.cap = make([]int, len(m.matchcap), cap(m.matchcap))
	}
	t.inst = i
	return t
}

// A lazyFlag is a lazily-evaluated syntax.EmptyOp,
// for checking zero-width flags like ^ $ \A \z \B \b.
// It records the pair of relevant runes and does not
// determine the implied flags until absolutely necessary
// (most of the time, that means never).

// in the string. The onePassPrefix skips over the mandatory
// EmptyBeginText.
func onePassPrefix(p *syntax.Prog) (prefix string, complete bool, pc uint32) {
	i := &p.Inst[p.Start]
	if i.Op != syntax.InstEmptyWidth || (syntax.EmptyOp(i.Arg))&syntax.EmptyBeginText == 0 {
		return "", i.Op == syntax.InstMatch, uint32(p.Start)
	}
	pc = i.Out
	i = &p.Inst[pc]
	for i.Op == syntax.InstNop {
		pc = i.Out
		i = &p.Inst[pc]
	}

					b.cap[inst.Arg] = pos
				}
				pc = inst.Out
				goto CheckAndLoop
			}

		case syntax.InstEmptyWidth:
			flag := i.context(pos)
			if !flag.match(syntax.EmptyOp(inst.Arg)) {
				continue
			}
			pc = inst.Out
			goto CheckAndLoop

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

		case syntax.InstMatch:

	}
	return c.loop(f1, nongreedy)
}

func (c *compiler) plus(f1 frag, nongreedy bool) frag {
	return frag{f1.i, c.loop(f1, nongreedy).out, f1.nullable}
}

func (c *compiler) empty(op EmptyOp) frag {
	f := c.inst(InstEmptyWidth)
	c.p.Inst[f.i].Arg = uint32(op)
	f.out = makePatchList(f.i << 1)
	return f
}

func (c *compiler) rune(r []rune, flags Flags) frag {
	f := c.inst(InstRune)

      CompileTimeConstantOperand<TF::DepthwiseConv2dNativeBackpropFilterOp, 1>,
      // $input_sizes
      CompileTimeConstantOperand<TF::DepthwiseConv2dNativeBackpropInputOp, 0>,
      CompileTimeConstantOperand<TF::EmptyOp, 0>,  // $shape
      // $element_shape, $max_num_elements
      CompileTimeConstantOperand<TF::EmptyTensorListOp, 0, 1>,
      CompileTimeConstantOperand<TF::ExpandDimsOp, 1>,   // $dim

    TypeID::get<TF::CumsumOp>(),
    TypeID::get<TF::DepthwiseConv2dNativeOp>(),
    TypeID::get<TF::DivOp>(),
    TypeID::get<TF::DynamicStitchOp>(),
    TypeID::get<TF::_EagerConstOp>(),
    TypeID::get<TF::EmptyOp>(),
    TypeID::get<TF::ExpandDimsOp>(),
    TypeID::get<TF::FakeQuantWithMinMaxVarsOp>(),
    TypeID::get<TF::FillOp>(),
    TypeID::get<TF::FusedBatchNormOp>(),
    TypeID::get<TF::FusedBatchNormGradOp>(),

      OperationName(mlir::TF::BroadcastGradientArgsOp::getOperationName(),
                    context),
      OperationName(mlir::TF::ConcatOffsetOp::getOperationName(), context),
      OperationName(mlir::TF::EmptyOp::getOperationName(), context),
      OperationName(mlir::TF::ListDiffOp::getOperationName(), context),
      OperationName(mlir::TF::RankOp::getOperationName(), context),

	mpool          int            // pool for machines
	matchcap       int            // size of recorded match lengths
	prefixComplete bool           // prefix is the entire regexp
	cond           syntax.EmptyOp // empty-width conditions required at start of match
	minInputLen    int            // minimum length of the input in bytes

	// This field can be modified by the Longest method,
	// but it is otherwise read-only.

  }
  return success();
}

//===----------------------------------------------------------------------===//
// EmptyOp
//===----------------------------------------------------------------------===//

OpFoldResult EmptyOp::fold(FoldAdaptor adaptor) {
  auto operands = adaptor.getOperands();
  assert(operands.size() == 1 && "empty op has one operand");