libcruft-util/cmdopt.ipp

/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Copyright 2013-2016 Danny Robson <danny@nerdcruft.net>
 */

#ifdef __UTIL_CMDLINE_IPP
#error
#endif
#define __UTIL_CMDLINE_IPP

#include <algorithm>
#include <iterator>
#include <sstream>

#include "./introspection.hpp"
#include "./iterator.hpp"

namespace util::cmdopt {
    ///////////////////////////////////////////////////////////////////////////
    template <typename T>
    option::value<T>::value (T &_data):
        m_data (_data)
    { ; }


    //-------------------------------------------------------------------------
    template <typename T>
    inline void
    option::value<T>::execute (const char *restrict str)
    {
        try {
            std::istringstream is (str);
            is.exceptions (
                  std::istringstream::failbit
                | std::istringstream::badbit
            );

            is >> m_data;
        } catch (...) {
            throw invalid_value (__func__);
        }

        seen (true);
    }


    //-------------------------------------------------------------------------
    namespace option {
    template <>
    inline void
    value<bool>::execute (const char *restrict str)
    {
        static const std::string TRUE_STRING[] = {
            "true",
            "yes",
            "y",
            "1"
        };

        if (std::any_of (std::begin (TRUE_STRING),
                         std::end (TRUE_STRING),
                         [str] (auto i) { return i == str; }))
        {
            m_data = true;
            return;
        }

        static const std::string FALSE_STRING[] = {
            "false",
            "no",
            "n",
            "0"
        };

        if (std::any_of (std::begin (FALSE_STRING),
                         std::end (FALSE_STRING),
                         [str] (auto i) { return i == str; }))
        {
            m_data = false;
            return;
        }

        base::execute (str);
        seen (true);
    }
    }


    //-------------------------------------------------------------------------
    namespace detail {
        template <typename T>
        std::enable_if_t<!std::is_enum<T>::value, const std::string&>
        value_example (void)
        {
            static const std::string EXAMPLE =
                std::string {"<"} +
                std::string {to_string<T> ()} +
                std::string {">"};

            return EXAMPLE;
        }

        template <typename T>
        std::enable_if_t<std::is_enum<T>::value, const std::string&>
        value_example (void)
        {
            static const std::string EXAMPLE = [] (void) {
                std::ostringstream os;
                std::copy (std::cbegin (enum_traits<T>::names),
                           std::cend   (enum_traits<T>::names),
                           infix_iterator<const char*> (os, "|"));
                return os.str ();
            } ();
            return EXAMPLE;
        }
    }


    //-------------------------------------------------------------------------
    template <typename T>
    const std::string&
    option::value<T>::example (void) const
    {
        return detail::value_example<T> ();
    }


    //-----------------------------------------------------------------------------
    template <typename T>
    const T&
    option::value<T>::data (void) const&
    {
        return m_data;
    }


    //-----------------------------------------------------------------------------
    template <typename T>
    T&
    option::value<T>::data (void) &
    {
        return m_data;
    }


    //-----------------------------------------------------------------------------
    template <typename T>
    T&
    option::value<T>::data (T _data) &
    {
        return m_data = _data;
    }


    ///////////////////////////////////////////////////////////////////////////
    template <typename T, typename ...Args>
    T&
    parser::add (char shortname,
                 std::string longname,
                 std::string description,
                 Args&&... args)
    {
        auto handler = std::make_unique<T> (std::forward<Args> (args)...);
        T& ref = *handler;

        m_short.emplace_back (shortname, ref);
        m_long .emplace_back (std::move (longname),  ref);

        m_options.emplace_back (std::move (description), std::move (handler));

        return ref;
    }


    //-------------------------------------------------------------------------
    template <typename T, typename ...Args>
    T&
    parser::append (std::string description,
                    Args &&...args)
    {
        auto handler = std::make_unique<T> (std::forward<Args> (args)...);
        auto &ref = *handler;
        m_positional.push_back (ref);
        m_options.emplace_back (std::move (description), std::move (handler));
        return ref;
    }
}