Moved buffer management into the lexer class and implemented YYFILL so that streams are read incrementally.
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5526de1385
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754c38e871
1 changed files with 50 additions and 16 deletions
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@ -3046,11 +3046,20 @@ class basic_json
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using lexer_char_t = unsigned char;
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/// constructor with a given buffer
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inline lexer(const string_t& s) noexcept
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: m_content(reinterpret_cast<const lexer_char_t*>(s.c_str()))
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inline lexer(const string_t& s) noexcept
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: m_buffer(s), m_stream(nullptr)
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{
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m_content = reinterpret_cast<const lexer_char_t*>(s.c_str());
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m_start = m_cursor = m_content;
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m_limit = m_content + s.size();
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}
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inline lexer(std::istream* s) noexcept
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: m_stream(s)
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{
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getline(*m_stream, m_buffer);
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m_content = reinterpret_cast<const lexer_char_t*>(m_buffer.c_str());
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m_start = m_cursor = m_content;
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m_limit = m_content + s.size();
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m_limit = m_content + m_buffer.size();
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}
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/// default constructor
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@ -3182,6 +3191,8 @@ class basic_json
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// remember the begin of the token
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m_start = m_cursor;
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#define YYFILL(n) { size_t offset_marker = m_marker - m_start; yyfill(n); m_marker = m_start + offset_marker; }
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/*!re2c
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re2c:define:YYCTYPE = lexer_char_t;
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re2c:define:YYCURSOR = m_cursor;
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@ -3190,7 +3201,6 @@ class basic_json
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re2c:indent:string = " ";
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re2c:indent:top = 1;
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re2c:labelprefix = "basic_json_parser_";
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re2c:yyfill:enable = 0;
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// whitespace
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ws = [ \t\n\r]+;
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@ -3240,8 +3250,28 @@ class basic_json
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// anything else is an error
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. { return token_type::parse_error; }
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*/
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}
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void yyfill(int n) noexcept
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{
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if (not m_stream or not *m_stream) return;
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ssize_t offset_start = m_start - m_content;
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ssize_t offset_cursor = m_cursor - m_start;
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ssize_t offset_limit = m_limit - m_start;
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m_buffer.erase(0, offset_start);
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std::string line;
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std::getline(*m_stream, line);
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m_buffer += line;
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m_content = reinterpret_cast<const lexer_char_t*>(m_buffer.c_str()); //reinterpret_cast<lexer_char_t*>(endptr)
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m_start = m_content + offset_start;
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m_cursor = m_start + offset_cursor;
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m_limit = m_start + offset_limit;
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}
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/// return string representation of last read token
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inline string_t get_token() const noexcept
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{
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@ -3404,14 +3434,20 @@ class basic_json
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}
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private:
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/// optional input stream
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std::istream* m_stream;
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/// the buffer
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string_t m_buffer;
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/// the buffer pointer
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const lexer_char_t* m_content = nullptr;
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/// pointer to he beginning of the current symbol
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/// pointer to the beginning of the current symbol
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const lexer_char_t* m_start = nullptr;
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/// pointer to the current symbol
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const lexer_char_t* m_cursor = nullptr;
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/// pointer to the end of the buffer
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const lexer_char_t* m_limit = nullptr;
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/// YYSTATE
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int m_state;
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};
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/*!
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@ -3421,24 +3457,24 @@ class basic_json
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{
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public:
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/// constructor for strings
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inline parser(const string_t& s) : m_buffer(s), m_lexer(m_buffer)
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inline parser(const string_t& s) : m_lexer(s)
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{
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// read first token
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get_token();
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}
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/// a parser reading from an input stream
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inline parser(std::istream& _is)
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inline parser(std::istream& _is) : m_lexer(&_is)
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{
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while (_is)
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{
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string_t input_line;
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std::getline(_is, input_line);
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m_buffer += input_line;
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}
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// while (_is)
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// {
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// string_t input_line;
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// std::getline(_is, input_line);
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// m_buffer += input_line;
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// }
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// initializer lexer
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m_lexer = lexer(m_buffer);
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// m_lexer = std::move(lexer(_is));
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// read first token
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get_token();
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@ -3625,8 +3661,6 @@ class basic_json
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}
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private:
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/// the buffer
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string_t m_buffer;
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/// the type of the last read token
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typename lexer::token_type last_token = lexer::token_type::uninitialized;
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/// the lexer
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