# Program Listing for File parser.hpp

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    /*-
     * SPDX-License-Identifier: BSD-2-Clause
     *
     * Copyright (c) 2020 NKI/AVL, Netherlands Cancer Institute
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions are met:
     *
     * 1. Redistributions of source code must retain the above copyright notice, this
     *    list of conditions and the following disclaimer
     * 2. Redistributions in binary form must reproduce the above copyright notice,
     *    this list of conditions and the following disclaimer in the documentation
     *    and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
     * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */

    #pragma once

    #include "cif++/row.hpp"

    #include <map>

    namespace cif
    {

    // --------------------------------------------------------------------

    class parse_error : public std::runtime_error
    {
      public:
        parse_error(uint32_t line_nr, const std::string &message)
            : std::runtime_error("parse error at line " + std::to_string(line_nr) + ": " + message)
        {
        }
    };

    // --------------------------------------------------------------------

    // TODO: Need to implement support for transformed long lines

    class sac_parser
    {
      public:
        struct iless_op
        {
            bool operator()(std::string a, std::string b) const
            {
                to_upper(a);
                to_upper(b);
                return a < b;
            }
        };

        using datablock_index = std::map<std::string, std::size_t, iless_op>;

        virtual ~sac_parser() = default;
        enum CharTraitsMask : uint8_t
        {
            kOrdinaryMask = 1 << 0,
            kNonBlankMask = 1 << 1,
            kTextLeadMask = 1 << 2,
            kAnyPrintMask = 1 << 3
        };

        static constexpr bool is_space(int ch)
        {
            return ch == ' ' or ch == '\t' or ch == '\r' or ch == '\n';
        }

        static constexpr bool is_white(int ch)
        {
            return is_space(ch) or ch == '#';
        }

        static constexpr bool is_ordinary(int ch)
        {
            return ch >= 0x20 and ch <= 0x7f and (kCharTraitsTable[ch - 0x20] & kOrdinaryMask) != 0;
        }

        static constexpr bool is_non_blank(int ch)
        {
            return ch > 0x20 and ch <= 0x7f and (kCharTraitsTable[ch - 0x20] & kNonBlankMask) != 0;
        }

        static constexpr bool is_text_lead(int ch)
        {
            return ch >= 0x20 and ch <= 0x7f and (kCharTraitsTable[ch - 0x20] & kTextLeadMask) != 0;
        }

        static constexpr bool is_any_print(int ch)
        {
            return ch == '\t' or
                   (ch >= 0x20 and ch <= 0x7f and (kCharTraitsTable[ch - 0x20] & kAnyPrintMask) != 0);
        }

        static bool is_unquoted_string(std::string_view text);

      protected:
        static constexpr uint8_t kCharTraitsTable[128] = {
            //  0   1   2   3   4   5   6   7   8   9   a   b   c   d   e   f
            14, 15, 14, 14, 14, 15, 15, 14, 15, 15, 15, 15, 15, 15, 15, 15, //  2
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 10, 15, 15, 15, 15, //  3
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, //  4
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 14, 15, 14, 15, 14, //  5
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, //  6
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 0,  //  7
        };

        enum class CIFToken
        {
            UNKNOWN,

            END_OF_FILE,

            DATA,
            LOOP,
            GLOBAL,
            SAVE_,
            SAVE_NAME,
            STOP,
            ITEM_NAME,
            VALUE
        };

        static constexpr const char *get_token_name(CIFToken token)
        {
            switch (token)
            {
                case CIFToken::UNKNOWN: return "Unknown";
                case CIFToken::END_OF_FILE: return "Eof";
                case CIFToken::DATA: return "DATA";
                case CIFToken::LOOP: return "LOOP";
                case CIFToken::GLOBAL: return "GLOBAL";
                case CIFToken::SAVE_: return "SAVE";
                case CIFToken::SAVE_NAME: return "SAVE+name";
                case CIFToken::STOP: return "STOP";
                case CIFToken::ITEM_NAME: return "Tag";
                case CIFToken::VALUE: return "Value";
                default: return "Invalid token parameter";
            }
        }

        // get_next_char takes the next character from the istream.
        // This function also does carriage/linefeed translation.
        int get_next_char();

        // Put the last read character back into the istream
        void retract();

        CIFToken get_next_token();

        void match(CIFToken token);

      public:

        bool parse_single_datablock(const std::string &datablock);

        datablock_index index_datablocks();

        bool parse_single_datablock(const std::string &datablock, const datablock_index &index);

        void parse_file();

      protected:

        sac_parser(std::istream &is, bool init = true);

        void parse_global();

        void parse_datablock();

        virtual void parse_save_frame();

        void error(const std::string &msg)
        {
            if (cif::VERBOSE > 0)
                std::cerr << "Error parsing mmCIF: " << msg << '\n';

            throw parse_error(m_line_nr, msg);
        }

        void warning(const std::string &msg)
        {
            if (cif::VERBOSE > 0)
                std::cerr << "parser warning at line " << m_line_nr << ": " << msg << '\n';
        }

        // production methods, these are pure virtual here

        virtual void produce_datablock(std::string_view name) = 0;
        virtual void produce_category(std::string_view name) = 0;
        virtual void produce_row() = 0;
        virtual void produce_item(std::string_view category, std::string_view item, std::string_view value) = 0;

      protected:

        enum class State
        {
            Start,
            White,
            Esc,
            Comment,
            QuestionMark,
            Dot,
            QuotedString,
            QuotedStringQuote,
            UnquotedString,
            ItemName,
            TextItem,
            TextItemNL,
            Reserved,
            Value
        };

        std::streambuf &m_source;

        // Parser state
        uint32_t m_line_nr;
        bool m_bol;
        CIFToken m_lookahead;

        // token buffer
        std::vector<char> m_token_buffer;
        std::string_view m_token_value;

    };

    // --------------------------------------------------------------------

    class parser : public sac_parser
    {
      public:
        parser(std::istream &is, file &file)
            : sac_parser(is)
            , m_file(file)
        {
        }

        void produce_datablock(std::string_view name) override;

        void produce_category(std::string_view name) override;

        void produce_row() override;

        void produce_item(std::string_view category, std::string_view item, std::string_view value) override;

      protected:
        file &m_file;
        datablock *m_datablock = nullptr;
        category *m_category = nullptr;
        row_handle m_row;

    };

    } // namespace cif