uniform_string_finder.hpp

/*
 * Copyright (c) 2024 The RefValue Project
 *
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 * of this software and associated documentation files (the "Software"), to deal
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 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * THE SOFTWARE.
 */
 
#pragma once
 
#include <cstddef>
#include <string_view>
 
namespace essence {
    enum class find_mode_type {
        any_of = 0,
        full_match,
        any_of_reverse,
        full_match_reverse,
        reserved,
    };
 
    template <find_mode_type>
    struct string_finder_traits {};
 
    template <>
    struct string_finder_traits<find_mode_type::any_of> {
        static constexpr std::size_t default_index{};
        static constexpr bool forward_direction = true;
        static constexpr auto find              = [](std::string_view source, std::string_view keyword,
                                         std::size_t index = default_index) {
            return source.find_first_of(keyword, index);
        };
 
        static constexpr auto keyword_size = [](std::string_view keyword) -> std::size_t { return 1; };
    };
 
    template <>
    struct string_finder_traits<find_mode_type::full_match> {
        static constexpr std::size_t default_index{};
        static constexpr bool forward_direction = true;
        static constexpr auto find              = [](std::string_view source, std::string_view keyword,
                                         std::size_t index = default_index) { return source.find(keyword, index); };
 
        static constexpr auto keyword_size = [](std::string_view keyword) { return keyword.size(); };
    };
 
    template <>
    struct string_finder_traits<find_mode_type::any_of_reverse> {
        static constexpr auto default_index = std::string_view::npos;
        static constexpr bool forward_direction{};
        static constexpr auto find = [](std::string_view source, std::string_view keyword,
                                         std::size_t index = default_index) {
            return source.find_last_of(keyword, index);
        };
 
        static constexpr auto keyword_size = [](std::string_view keyword) -> std::size_t { return 1; };
    };
 
    template <>
    struct string_finder_traits<find_mode_type::full_match_reverse> {
        static constexpr auto default_index = std::string_view::npos;
        static constexpr bool forward_direction{};
        static constexpr auto find = [](std::string_view source, std::string_view keyword,
                                         std::size_t index = default_index) { return source.rfind(keyword, index); };
 
        static constexpr auto keyword_size = [](std::string_view keyword) { return keyword.size(); };
    };
 
    template <find_mode_type Mode>
    constexpr auto uniform_find_string(std::string_view source, std::string_view keyword,
        std::size_t index      = string_finder_traits<Mode>::default_index,
        bool plus_keyword_size = false) noexcept(noexcept(string_finder_traits<Mode>::find(source, keyword, index))) {
        auto found_index = string_finder_traits<Mode>::find(source, keyword, index);
 
        if (plus_keyword_size && found_index != std::string_view::npos) {
            found_index += string_finder_traits<Mode>::keyword_size(keyword);
        }
 
        return found_index;
    }
 
    template <find_mode_type Mode>
    constexpr auto skip_keyword(std::size_t index, std::string_view keyword) noexcept {
        if constexpr (string_finder_traits<Mode>::forward_direction) {
            return index + string_finder_traits<Mode>::keyword_size(keyword);
        } else {
            return index - string_finder_traits<Mode>::keyword_size(keyword);
        }
    }
} // namespace essence