transform.hpp

Go to the documentation of this file.

// -----------------------------------------------------------------------------------------------------
// Copyright (c) 2006-2019, Knut Reinert & Freie Universität Berlin
// Copyright (c) 2016-2019, Knut Reinert & MPI für molekulare Genetik
// This file may be used, modified and/or redistributed under the terms of the 3-clause BSD-License
// shipped with this file and also available at: https://github.com/seqan/seqan3/blob/master/LICENSE.md
// -----------------------------------------------------------------------------------------------------

#pragma once

#include <array>
#include <cmath>

#include <seqan3/core/concept/core_language.hpp>
#include <seqan3/core/detail/int_types.hpp>

namespace seqan3::detail
{

template <typename char_type>
inline std::array<char_type, detail::size_in_values_v<char_type>> constexpr to_lower_table
{
    [] () constexpr
    {
        std::array<char_type, detail::size_in_values_v<char_type>> ret{};

        for (size_t i = 0; i < detail::size_in_values_v<char_type>; ++i)
            ret[i] = i;

        for (size_t i = char_type{'A'}; i <= char_type{'Z'}; ++i)
            ret[i] = ret[i] - char_type{'A'} + char_type{'a'};

        return ret;
    } ()
};

template <typename char_type>
inline std::array<char_type, detail::size_in_values_v<char_type>> constexpr to_upper_table
{
    [] () constexpr
    {
        std::array<char_type, detail::size_in_values_v<char_type>> ret{};

        for (size_t i = 0; i < detail::size_in_values_v<char_type>; ++i)
            ret[i] = i;

        for (size_t i = char_type{'a'}; i <= char_type{'z'}; ++i)
            ret[i] = ret[i] - char_type{'a'} + char_type{'A'};

        return ret;
    } ()
};

} // namespace seqan3::detail

namespace seqan3
{

template <Char char_type>
constexpr char_type to_lower(char_type const c) noexcept
{
    using u_t = std::make_unsigned_t<char_type>;
    return detail::to_lower_table<char_type>[static_cast<u_t>(c)];
}

template <Char char_type>
constexpr char_type to_upper(char_type const c) noexcept
{
    using u_t = std::make_unsigned_t<char_type>;
    return detail::to_upper_table<char_type>[static_cast<u_t>(c)];
}

} // namespace seqan3