// @HEADER
// ************************************************************************
//
//               Rapid Optimization Library (ROL) Package
//                 Copyright (2014) Sandia Corporation
//
// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
// license for use of this work by or on behalf of the U.S. Government.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Questions? Contact lead developers:
//              Drew Kouri   (dpkouri@sandia.gov) and
//              Denis Ridzal (dridzal@sandia.gov)
//
// ************************************************************************
// @HEADER

#ifndef ROL_ELEMENTWISE_FUNCTION_H
#define ROL_ELEMENTWISE_FUNCTION_H

#include "Teuchos_CommHelpers.hpp"

namespace ROL {

template<class Real>
class Vector;

namespace Elementwise {

// Interface class with function of a single argument
template<class Real>
class UnaryFunction {
public:
  virtual ~UnaryFunction() {}
  virtual Real apply( const Real &x ) const = 0;
};

// Wrap a generic function/functor of a single argument
template<class Real, class Func>
class UnaryFunctionWrapper : public UnaryFunction<Real> {
public:
  UnaryFunctionWrapper( const Func &f ) : f_(f) {}
  
  Real apply( const Real &x ) const {
    return f_(x);
  }
private:
  Func f_;
};

// Apply a Unary function to a ROL Vector
template<class Real>
void applyUnaryInPlace(ROL::Vector<Real> &x, const UnaryFunction<Real> &f) {
  x.applyUnary(f);
}

// Wrap a generic single argument function or functor and and apply it to a ROL Vector
template<class Real, class Func>
void applyUnaryInPlace(ROL::Vector<Real> &x, Func f) {
  UnaryFunctionWrapper<Real,Func> f_wrapped(f);
  x.applyUnary(f_wrapped);
}



// Interface class with function of two arguments
template<class Real>
class BinaryFunction {
public:
  virtual ~BinaryFunction() {}
  virtual Real apply( const Real &x, const Real &y ) const = 0;
};


// Wrap a generic function/functor of two arguments
template<class Real, class Func>
class BinaryFunctionWrapper : public BinaryFunction<Real> {
public:
  BinaryFunctionWrapper( const Func &f ) : f_(f) {}
  
  Real apply( const Real &x, const Real &y ) const {
    return f_(x,y); 
  }
private:
  Func f_;   
};

// Apply a Binary function to a ROL Vector
template<class Real>
void applyBinaryInPlace(ROL::Vector<Real> &x, const ROL::Vector<Real> &y, const BinaryFunction<Real> &f) {
  x.applyBinary(f,y);
}


// Wrap a generic two argument function or functor and and apply it to a ROL Vector
template<class Real, class Func>
void applyBinaryInPlace(ROL::Vector<Real> &x, const ROL::Vector<Real> &y, Func f) {
  BinaryFunctionWrapper<Real,Func> f_wrapped(f);
  x.applyBinary(f_wrapped,y);
}


} // namespace Elementwise 
} // namespace ROL

#include <ROL_Elementwise_Reduce.hpp>
#include <ROL_UnaryFunctions.hpp>
#include <ROL_BinaryFunctions.hpp>

#endif
