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*
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/*interface file for swig */

%module model_loss
%include "std_string.i"
%{
#include "singa/model/loss.h"
  using singa::Tensor;
%}

namespace singa {
class Loss {
public:
  Loss() = default;
  virtual ~Loss() {}

  virtual Tensor Forward(int flag, const Tensor &prediction,
                         const Tensor &target) = 0;

  float Evaluate(int flag, const Tensor &prediction, const Tensor &target);

  /// Compute the gradients of the loss values w.r.t. the prediction.
  virtual Tensor Backward() = 0;
};

class MSE : public Loss {
public:
  Tensor Forward(int flag, const Tensor &prediction, const Tensor &target)
      override;

  Tensor Backward() override;
};

class SoftmaxCrossEntropy : public Loss {
public:
  Tensor Forward(int flag, const Tensor &prediction, const Tensor &target)
      override;

  Tensor Backward() override;
};

}