Functional.h

/*
 * $Id: List.h 2839 2009-09-28 11:36:20Z karijes $
 *
 * Functional approach for lists
 * Copyright (c) 2005-2011 edelib authors
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library. If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef __EDELIB_FUNCTIONAL_H__
#define __EDELIB_FUNCTIONAL_H__

#include "Debug.h"

EDELIB_NS_BEGIN

template <typename T, typename F>
unsigned int filter(const F& func, const T& container, T& ret) {
        typename T::const_iterator it  = container.begin();
        typename T::const_iterator ite = container.end();

        for(; it != ite; ++it) {
                if(func(*it))
                        ret.push_back(*it);
        }

        return ret.size();
}

template <typename T, typename F>
void map(F& func, const T& container, T& ret) {
        typename T::const_iterator it  = container.begin();
        typename T::const_iterator ite = container.end();

        for(; it != ite; ++it)
                ret.push_back(func(*it));
}

template <typename T, typename R, typename F>
void reduce(F& func, const T& container, R& ret) {
        unsigned int sz = container.size();
        if(sz == 0) {
                // nothing
        } else if(sz == 1)
                ret = *container.begin();
        else {
                typename T::const_iterator it  = container.begin();
                typename T::const_iterator it2 = it;
                ++it2;
                typename T::const_iterator ite = container.end();

                ret = func(*it, *it2);
                for(++it2; it2 != ite; ++it2)
                        ret = func(*it2, ret);
        }
}

template <typename T, typename F>
void for_each(const F& func, const T& container) {
        typename T::const_iterator it  = container.begin();
        typename T::const_iterator ite = container.end();

        for(; it != ite; ++it)
                func(*it);
}

template <typename T, typename F>
void for_each(const F& func, const T& container, void* p) {
        typename T::const_iterator it  = container.begin();
        typename T::const_iterator ite = container.end();

        for(; it != ite; ++it)
                func(*it, p);
}

EDELIB_NS_END
#endif