filter.h

// -*- mode: c++; tab-width: 4; indent-tabs-mode: t; eval: (progn (c-set-style "stroustrup") (c-set-offset 'innamespace 0)); -*-
// vi:set ts=4 sts=4 sw=4 noet :
// Copyright 2015 The TPIE development team
// 
// This file is part of TPIE.
// 
// TPIE 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 3 of the License, or (at your
// option) any later version.
// 
// TPIE 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 TPIE.  If not, see <http://www.gnu.org/licenses/>

#ifndef __TPIE_PIPELINING_FILTER_H__
#define __TPIE_PIPELINING_FILTER_H__

#include <tpie/pipelining/map.h>
#include <tpie/pipelining/node.h>
#include <tpie/pipelining/pipe_base.h>
#include <tpie/pipelining/factory_helpers.h>
#include <tpie/pipelining/node_name.h>

namespace tpie {
namespace pipelining {
namespace bits {

template <typename F>
class filter_t {
public:
    template <typename dest_t>
    class type: public node {
    private:
        F functor;
        dest_t dest;
    public:
        typedef typename std::decay<typename unary_traits<F>::argument_type>::type funct_arg_type;
        typedef typename push_type<dest_t, funct_arg_type>::type item_type;
        type(dest_t dest, const F & functor):
            functor(functor), dest(std::move(dest)) {
            set_name(bits::extract_pipe_name(typeid(F).name()), PRIORITY_NO_NAME);
        }
        
        void push(const item_type & item) {
            if (functor(item))
                dest.push(item);
        }
    };
};

} //namespace bits

template <typename F>
pipe_middle<tempfactory<bits::filter_t<F>, F> > filter(const F & functor) {
    return tempfactory<bits::filter_t<F>, F >(functor);
}

} //namespace pipelining
} //namespace terrastream

#endif //__TPIE_PIPELINING_FILTER_H__