map.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 2011, 2012, 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_MAP_H__
#define __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>
#include <type_traits>
 
namespace tpie::pipelining {
namespace bits {
 
template <typename T>
struct unary_traits_imp;
 
template <typename C, typename R, typename A>
struct unary_traits_imp<R(C::*)(A)> {
    typedef A argument_type;
    typedef R return_type;
};
 
template <typename C, typename R, typename A>
struct unary_traits_imp<R(C::*)(A) const > {
    typedef A argument_type;
    typedef R return_type;
};
 
template <typename R, typename A>
struct unary_traits_imp<R(*)(A)> {
    typedef A argument_type;
    typedef R return_type;
};
 
template <typename T>
struct unary_traits: public unary_traits_imp<decltype(&T::operator()) > {};
 
template <typename dest_t, typename F>
class map_t: public node {
private:
    F functor;
    dest_t dest;
public:
    typedef typename std::decay<typename unary_traits<F>::argument_type>::type item_type;
    
    map_t(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) {
        dest.push(functor(item));
    }
};
 
template <typename dest_t, typename F>
class map_temp_t: public node {
private:
    F functor;
    dest_t dest;
public:
    map_temp_t(dest_t dest, const F & functor):
        functor(functor), dest(std::move(dest)) {
        set_name(bits::extract_pipe_name(typeid(F).name()), PRIORITY_NO_NAME);
    }
    
    template <typename T>
    void push(const T & item) {
        dest.push(functor(item));
    }
};
 
template <typename F>
class map_sink_t: public node {
private:
    F functor;
public:
    typedef typename std::decay<typename unary_traits<F>::argument_type>::type item_type;
 
    map_sink_t(const F & functor):
        functor(functor) {
        set_name(bits::extract_pipe_name(typeid(F).name()), PRIORITY_NO_NAME);
    }
    
    void push(const item_type & item) {
        functor(item);
    }
};
 
template <typename src_t, typename F>
class pull_map_t: public node {
private:
    F functor;
    src_t src;
public:
    pull_map_t(src_t src, const F & functor):
        functor(functor), src(std::move(src)) {
        set_name(bits::extract_pipe_name(typeid(F).name()), PRIORITY_NO_NAME);
    }
    
    auto pull() {
        return functor(src.pull());
    }
    
    bool can_pull() {
        return src.can_pull();
    }
};
 
 
template <typename T>
struct has_argument_type {
    typedef char yes[1];
    typedef char no[2];
 
    // This does not seem to work as well as it should
    // template <typename C>
    // static yes& test(typename unary_traits_imp<decltype(&C::operator())>::argument_type *);
 
    template <typename C>
    static yes& test(decltype(&C::operator()) *);
 
    template <typename>
    static no& test(...);
    static const bool value = sizeof(test<T>(nullptr)) == sizeof(yes);
};
 
} //namespace bits
 
template <typename F, typename = typename std::enable_if<bits::has_argument_type<F>::value>::type>
pipe_middle<tfactory<bits::map_t, Args<F>, F> > map(const F & functor) {
    return {functor};
}
 
template <typename F, typename = typename std::enable_if<!bits::has_argument_type<F>::value>::type>
pipe_middle<tfactory<bits::map_temp_t, Args<F>, F> > map(const F & functor) {
    return {functor};
}
 
template <typename F>
pipe_end<termfactory<bits::map_sink_t<F>, F> > map_sink(const F & functor) {
    return {functor};
}
 
template <typename F>
pullpipe_middle<tfactory<bits::pull_map_t, Args<F>, F>> pull_map(const F & functor) {
    return {functor};
}
 
} //namespace terrastream::pipelining
 
#endif //__TPIE_PIPELINING_MAP_H__