/* Copyright (C) 2004 Ariya Hidayat <ariya@kde.org>

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; either version 2
   of the License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; see the file COPYING.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.
*/


#ifndef FUNCTIONS
#define FUNCTIONS

#include <QStringList>
#include <QVector>
#include "hmath.h"

class Function;
class Evaluator;

class FunctionPrivate;
class FunctionRepositoryPrivate;

typedef QVector<HNumber> FunctionArguments;
typedef HNumber (*FunctionPtr)( const Evaluator*, Function*, const FunctionArguments& );

class Function
{
public:
    Function( const QString& name, int argc, FunctionPtr ptr, const QString& desc );
    Function( const QString& name, FunctionPtr ptr, const QString& desc );
    ~Function();
    QString name() const;
    QString description() const;
    QString error() const;
    void setError( const QString& context, const QString& error );
    HNumber exec( const Evaluator*, const FunctionArguments& args );

private:
    FunctionPrivate* d;
    Function( const Function& );
    Function& operator=( const Function& );
};

class FunctionRepository
{
public:
    FunctionRepository();
    ~FunctionRepository();
    static FunctionRepository* self();
    void add( Function* function );
    Function* function( const QString& name );
    QStringList functionNames() const;
private:
    FunctionRepositoryPrivate* d;
    static FunctionRepository* s_self;
    FunctionRepository( const FunctionRepository& );
    FunctionRepository& operator=( const FunctionRepository& );
};


#endif // FUNCTIONS