SUnary.h

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#ifndef OPAL_SUnary_HH
#define OPAL_SUnary_HH
 
// ------------------------------------------------------------------------
// $RCSfile: SUnary.h,v $
// ------------------------------------------------------------------------
// $Revision: 1.1.1.1 $
// ------------------------------------------------------------------------
// Copyright: see Copyright.readme
// ------------------------------------------------------------------------
//
// Template class: SUnary<T,U>
//
// ------------------------------------------------------------------------
//
// $Date: 2000/03/27 09:33:42 $
// $Author: Andreas Adelmann $
//
// ------------------------------------------------------------------------
 
#include <cerrno>
#include <iostream>
#include "AbstractObjects/Expressions.h"
#include "Expressions/SConstant.h"
#include "Expressions/TFunction1.h"
#include "Utilities/DomainError.h"
#include "Utilities/OverflowError.h"
 
namespace Expressions {
 
    // Template Class SUnary
    // ----------------------------------------------------------------------
    //  This expression evaluates a scalar operand, and then returns the
    //  result of applying a scalar function to the result.
 
    template <class T, class U>
    class SUnary : public Scalar<T> {
    public:
        //  Use scalar function of one operand and a scalar operand.
        SUnary(const TFunction1<T, U>& function, PtrToScalar<U> operand);
 
        SUnary(const SUnary<T, U>&);
        virtual ~SUnary();
 
        virtual Scalar<T>* clone() const;
 
        virtual T evaluate() const;
 
        //  If the operand is constant and the function is not a random
        //  generator, evaluate the expression and  store the result as a
        //  constant.
        static Scalar<T>* make(const TFunction1<T, U>& function, PtrToScalar<U> operand);
 
        virtual void print(std::ostream&, int precedence = 99) const;
 
    private:
        // Not implemented.
        SUnary();
        void operator=(const SUnary&);
 
        // The operation object.
        const TFunction1<T, U>& fun;
 
        // The two operands.
        PtrToScalar<U> opr;
    };
 
    // Implementation
    // ------------------------------------------------------------------------
 
    template <class T, class U>
    inline SUnary<T, U>::SUnary(const SUnary<T, U>& rhs)
        : Scalar<T>(rhs), fun(rhs.fun), opr(rhs.opr->clone()) {}
 
    template <class T, class U>
    inline SUnary<T, U>::SUnary(const TFunction1<T, U>& function, PtrToScalar<U> oper)
        : fun(function), opr(oper) {}
 
    template <class T, class U>
    inline SUnary<T, U>::~SUnary() {}
 
    template <class T, class U>
    inline Scalar<T>* SUnary<T, U>::clone() const {
        return new SUnary<T, U>(*this);
    }
 
    template <class T, class U>
    inline T SUnary<T, U>::evaluate() const {
        errno    = 0;
        U arg    = opr->evaluate();
        T result = (*fun.function)(arg);
 
        // Test for run-time evaluation errors.
        switch (errno) {
            case EDOM:
                throw DomainError("SUnary::evaluate()");
 
            case ERANGE:
                // Ignore underflow.
                if (result == T(0)) return result;
                throw OverflowError("SUnary::evaluate()");
 
            default:;
        }
 
        return result;
    }
 
    template <class T, class U>
    inline Scalar<T>* SUnary<T, U>::make(const TFunction1<T, U>& function, PtrToScalar<U> operand) {
        // We must pick up the constant flag before the ownership of "operand"
        // is transferred to "result".
        bool isConst          = operand->isConstant();
        PtrToScalar<T> result = new SUnary<T, U>(function, operand);
        ;
 
        if (function.precedence != -2) {
            if (isConst) {
                // Constant expression.
                double value = result->evaluate();
                result       = new SConstant<T>(value);
            }
        }
 
        // Other expression.
        return result.release();
    }
 
    template <class T, class U>
    inline void SUnary<T, U>::print(std::ostream& os, int precedence) const {
        if (fun.precedence >= 0) {
            if (fun.precedence <= precedence) os << "(";
            os << fun.name;
            opr->print(os, fun.precedence);
            if (fun.precedence <= precedence) os << ")";
        } else {
            os << fun.name << "(";
            opr->print(os, 0);
            os << ")";
        }
    }
 
}  // namespace Expressions
 
#endif  // OPAL_SUnary_HH