//          Copyright Joakim Karlsson & Kim Gräsman 2010-2012.
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)

#ifndef SNOWHOUSE_OROPERATOR_H
#define SNOWHOUSE_OROPERATOR_H

#include "constraintoperator.h"

namespace snowhouse
{
    struct OrOperator : public ConstraintOperator
    {
        template <typename ConstraintListType, typename ActualType>
        void Evaluate(ConstraintListType& list,
            ResultStack& result,
            OperatorStack& operators,
            const ActualType& actual)
        {
            EvaluateOperatorsWithLessOrEqualPrecedence(
                *this, operators, result);

            operators.push(this);

            EvaluateConstraintList(list.m_tail, result, operators, actual);
        }

        void PerformOperation(ResultStack& result) override
        {
            if (result.size() < 2)
            {
                throw InvalidExpressionException(
                    "The expression contains an \"or\" operator with too few "
                    "operands");
            }

            bool right = result.top();
            result.pop();
            bool left = result.top();
            result.pop();

            result.push(left || right);
        }

        int Precedence() const override
        {
            return 4;
        }
    };

    template <>
    struct Stringizer<OrOperator>
    {
        static std::string ToString(const OrOperator&)
        {
            return "or";
        }
    };
}

#endif
