ASUnary.h

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#ifndef OPAL_ASUnary_HH
#define OPAL_ASUnary_HH 1
 
// ------------------------------------------------------------------------
// $RCSfile: ASUnary.h,v $
// ------------------------------------------------------------------------
// $Revision: 1.1.1.1 $
// ------------------------------------------------------------------------
// Copyright: see Copyright.readme
// ------------------------------------------------------------------------
//
// Template class: ASUnary<T>
//
// ------------------------------------------------------------------------
//
// $Date: 2000/03/27 09:33:41 $
// $Author: Andreas Adelmann $
//
// ------------------------------------------------------------------------
 
#include <cerrno>
#include <iosfwd>
#include <vector>
#include "AbstractObjects/Expressions.h"
#include "Expressions/SConstant.h"
#include "Expressions/TFunction1.h"
#include "Utilities/DomainError.h"
#include "Utilities/OverflowError.h"
 
namespace Expressions {
 
    // Template Class ASUnary
    // ----------------------------------------------------------------------
    //  This expression first evaluates its operand to get an array.
    //  The scalar result is computed then by applying a scalar-valued
    //  function to this array (e. g. minimum or maximum).
 
    template <class T>
    class ASUnary : public Scalar<T> {
    public:
        //  Use a function which maps a std::vector<T> to a T and an array
        //  expression.
        ASUnary(const TFunction1<T, const std::vector<T>&>& function, PtrToArray<T>& oper);
 
        ASUnary(const ASUnary<T>&);
        virtual ~ASUnary();
 
        virtual Scalar<T>* clone() const;
 
        virtual T evaluate() const;
 
        //  If all component of the argument are constant, then evaluate
        //  and store the result as a constant.
        static PtrToScalar<T> make(
                const TFunction1<T, const std::vector<T>&>& function, PtrToArray<T>& oper);
 
        virtual void print(std::ostream&, int precedence = 99) const;
 
    private:
        // Not implemented.
        ASUnary();
        void operator=(const ASUnary&);
 
        // The operation object.
        const TFunction1<T, const std::vector<T>&>& fun;
 
        // The operand.
        PtrToArray<T> opr;
    };
 
    // Implementation
    // ----------------------------------------------------------------------
 
    template <class T>
    inline ASUnary<T>::ASUnary(const ASUnary<T>& rhs)
        : Scalar<T>(rhs), fun(rhs.fun), opr(rhs.opr->clone()) {}
 
    template <class T>
    inline ASUnary<T>::ASUnary(
            const TFunction1<T, const std::vector<T>&>& function, PtrToArray<T>& oper)
        : fun(function), opr(oper) {}
 
    template <class T>
    inline ASUnary<T>::~ASUnary() {}
 
    template <class T>
    inline Scalar<T>* ASUnary<T>::clone() const {
        return new ASUnary<T>(*this);
    }
 
    template <class T>
    inline T ASUnary<T>::evaluate() const {
        errno                    = 0;
        const std::vector<T> arg = opr->evaluate();
        T result                 = (*fun.function)(arg);
 
        // Test for run-time evaluation errors.
        switch (errno) {
            case EDOM:
                throw DomainError("ASUnary::evaluate()");
 
            case ERANGE:
                // Ignore underflow.
                if (result == T(0)) return result;
                throw OverflowError("ASUnary::evaluate()");
 
            default:;
        }
 
        return result;
    }
 
    template <class T>
    inline PtrToScalar<T> ASUnary<T>::make(
            const TFunction1<T, const std::vector<T>&>& function, PtrToArray<T>& oper) {
        // We must pick up the constant flag before the ownership of "oper"
        // is transferred to "result".
        bool isConst          = oper->isConstant();
        PtrToScalar<T> result = new ASUnary<T>(function, oper);
 
        if (function.precedence != -2) {
            // Not a random expression.
            if (isConst) {
                // Replace constant expression by its value.
                result = new SConstant<T>(result->evaluate());
            }
        }
 
        // Other expression.
        return result.release();
    }
 
    template <class T>
    inline void ASUnary<T>::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_ASUnary_HH