.. _program_listing_file_cif++_parser.hpp:

Program Listing for File parser.hpp
===================================

|exhale_lsh| :ref:`Return to documentation for file <file_cif++_parser.hpp>` (``cif++/parser.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   /*-
    * 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_view a, std::string_view b) const
           {
               return icompare(a, b) < 0;
           }
       };
   
       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