static llvm::StringRef getDialectNamespace() { return "mlrt"; }

  mlir::Type parseType(mlir::DialectAsmParser &parser) const override;
  void printType(mlir::Type type, mlir::DialectAsmPrinter &os) const override;
};

// The MLIR type represents a C++ mlrt::Future.
class FutureType
    : public mlir::Type::TypeBase<FutureType, mlir::Type, mlir::TypeStorage> {
 public:
  using Base::Base;

 public:
  explicit FallbackDialect(MLIRContext *context);
  static StringRef getDialectNamespace() { return "tfrt_fallback"; }

  Type parseType(DialectAsmParser &parser) const override;
  void printType(Type type, DialectAsmPrinter &os) const override;
};

// The MLIR type represents a tensorflow::Tensor.
class TFTensorType : public Type::TypeBase<TFTensorType, Type, TypeStorage> {
 public:
  using Base::Base;

  parser.emitError(parser.getNameLoc(), "unknown type: ") << keyword;
  return Type();
}

/// Print a type registered to this dialect.
void FallbackDialect::printType(Type type, DialectAsmPrinter &os) const {
  if (mlir::isa<TFTensorType>(type)) {
    os << "tf_tensor";
    return;
  }

  if (mlir::isa<TFAllocatorType>(type)) {
    os << "tf_allocator";
    return;
  }

  static llvm::StringRef getDialectNamespace() { return "tf_mlrt"; }

  mlir::Type parseType(mlir::DialectAsmParser &parser) const override;
  void printType(mlir::Type type, mlir::DialectAsmPrinter &os) const override;
};

// The MLIR type represents a tensorflow::Tensor.
class TFTensorType
    : public mlir::Type::TypeBase<TFTensorType, mlir::Type, mlir::TypeStorage> {
 public:
  using Base::Base;

  // Parse a type registered to this dialect.
  Type parseType(DialectAsmParser &parser) const override;

  // Prints a type registered to this dialect.
  void printType(Type ty, DialectAsmPrinter &os) const override;
};

}  // namespace TFR
}  // namespace mlir

#define GET_OP_CLASSES
#include "tensorflow/compiler/mlir/tfr/ir/tfr_ops.h.inc"

  // Parses a type registered to this dialect.
  Type parseType(DialectAsmParser &parser) const override;

  // Prints a type registered to this dialect.
  void printType(Type type, DialectAsmPrinter &os) const override;
};

// The Control type is a token-like value that models control dependencies from
// TensorFlow graphs.
class ControlType : public Type::TypeBase<ControlType, Type, TypeStorage> {
 public:

  return mlir::Type();
}

// Print a type registered to this dialect.
void TensorflowMlrtDialect::printType(mlir::Type type,
                                      mlir::DialectAsmPrinter &os) const {
  if (mlir::isa<TFTensorType>(type)) {
    os << "tensor";
    return;
  }

  llvm_unreachable("unexpected tf_mlrt type kind");
}

}  // namespace tf_mlrt
}  // namespace tensorflow

  return mlir::Type();
}

// Print a type registered to this dialect.
void MlrtDialect::printType(mlir::Type type,
                            mlir::DialectAsmPrinter &os) const {
  if (mlir::isa<FutureType>(type)) {
    os << "future";
    return;
  }

  if (mlir::isa<PromiseType>(type)) {
    os << "promise";
    return;
  }

  } else {
    parser.emitError(parser.getNameLoc(), "unknown type " + typeNameSpelling);
    return {};
  }
}

void TFRDialect::printType(Type type, DialectAsmPrinter &os) const {
  llvm::ArrayRef<StringAttr> attrs;

  if (type.isa<TFRAttrType>()) {
    os << "attr";
    return;
  }
  if (auto tensor_ty = type.dyn_cast<TFRTensorType>()) {

  parser.emitError(parser.getNameLoc())
      << "unknown tf_executor type: " << data_type;
  return nullptr;
}

void TensorFlowExecutorDialect::printType(Type type,
                                          DialectAsmPrinter &os) const {
  if (mlir::isa<ControlType>(type)) {
    os << "control";
    return;
  }
  if (mlir::isa<TokenType>(type)) {
    os << "token";
    return;
  }