diff options
author | Daniel Friesel <daniel.friesel@uos.de> | 2020-09-07 12:57:04 +0200 |
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committer | Daniel Friesel <daniel.friesel@uos.de> | 2020-09-07 12:57:04 +0200 |
commit | 0558244645611f314f47e0fa427f7323ce253eaf (patch) | |
tree | 824bcd55ec8577703345106d0a08e167407500a7 /include/lib/modernjson/detail/input/parser.hpp | |
parent | 0248c6352f2117e50fac71dd632a79d8fa4f8737 (diff) |
remove external libraries from main branch
Diffstat (limited to 'include/lib/modernjson/detail/input/parser.hpp')
-rw-r--r-- | include/lib/modernjson/detail/input/parser.hpp | 504 |
1 files changed, 0 insertions, 504 deletions
diff --git a/include/lib/modernjson/detail/input/parser.hpp b/include/lib/modernjson/detail/input/parser.hpp deleted file mode 100644 index d205bbb..0000000 --- a/include/lib/modernjson/detail/input/parser.hpp +++ /dev/null @@ -1,504 +0,0 @@ -#pragma once - -#include <cassert> // assert -#include <cmath> // isfinite -#include <cstdint> // uint8_t -#include <functional> // function -#include <string> // string -#include <utility> // move - -#include <lib/modernjson/detail/exceptions.hpp> -#include <lib/modernjson/detail/macro_scope.hpp> -#include <lib/modernjson/detail/meta/is_sax.hpp> -#include <lib/modernjson/detail/input/input_adapters.hpp> -#include <lib/modernjson/detail/input/json_sax.hpp> -#include <lib/modernjson/detail/input/lexer.hpp> -#include <lib/modernjson/detail/value_t.hpp> - -namespace nlohmann -{ -namespace detail -{ -//////////// -// parser // -//////////// - -/*! -@brief syntax analysis - -This class implements a recursive decent parser. -*/ -template<typename BasicJsonType> -class parser -{ - using number_integer_t = typename BasicJsonType::number_integer_t; - using number_unsigned_t = typename BasicJsonType::number_unsigned_t; - using number_float_t = typename BasicJsonType::number_float_t; - using string_t = typename BasicJsonType::string_t; - using lexer_t = lexer<BasicJsonType>; - using token_type = typename lexer_t::token_type; - - public: - enum class parse_event_t : uint8_t - { - /// the parser read `{` and started to process a JSON object - object_start, - /// the parser read `}` and finished processing a JSON object - object_end, - /// the parser read `[` and started to process a JSON array - array_start, - /// the parser read `]` and finished processing a JSON array - array_end, - /// the parser read a key of a value in an object - key, - /// the parser finished reading a JSON value - value - }; - - using parser_callback_t = - std::function<bool(int depth, parse_event_t event, BasicJsonType& parsed)>; - - /// a parser reading from an input adapter - explicit parser(detail::input_adapter_t&& adapter, - const parser_callback_t cb = nullptr, - const bool allow_exceptions_ = true) - : callback(cb), m_lexer(std::move(adapter)), allow_exceptions(allow_exceptions_) - { - // read first token - get_token(); - } - - /*! - @brief public parser interface - - @param[in] strict whether to expect the last token to be EOF - @param[in,out] result parsed JSON value - - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - */ - void parse(const bool strict, BasicJsonType& result) - { - if (callback) - { - json_sax_dom_callback_parser<BasicJsonType> sdp(result, callback, allow_exceptions); - sax_parse_internal(&sdp); - result.assert_invariant(); - - // in strict mode, input must be completely read - if (strict and (get_token() != token_type::end_of_input)) - { - sdp.parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - parse_error::create(101, m_lexer.get_position(), - exception_message(token_type::end_of_input, "value"))); - } - - // in case of an error, return discarded value - if (sdp.is_errored()) - { - result = value_t::discarded; - return; - } - - // set top-level value to null if it was discarded by the callback - // function - if (result.is_discarded()) - { - result = nullptr; - } - } - else - { - json_sax_dom_parser<BasicJsonType> sdp(result, allow_exceptions); - sax_parse_internal(&sdp); - result.assert_invariant(); - - // in strict mode, input must be completely read - if (strict and (get_token() != token_type::end_of_input)) - { - sdp.parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - parse_error::create(101, m_lexer.get_position(), - exception_message(token_type::end_of_input, "value"))); - } - - // in case of an error, return discarded value - if (sdp.is_errored()) - { - result = value_t::discarded; - return; - } - } - } - - /*! - @brief public accept interface - - @param[in] strict whether to expect the last token to be EOF - @return whether the input is a proper JSON text - */ - bool accept(const bool strict = true) - { - json_sax_acceptor<BasicJsonType> sax_acceptor; - return sax_parse(&sax_acceptor, strict); - } - - template <typename SAX> - bool sax_parse(SAX* sax, const bool strict = true) - { - (void)detail::is_sax_static_asserts<SAX, BasicJsonType> {}; - const bool result = sax_parse_internal(sax); - - // strict mode: next byte must be EOF - if (result and strict and (get_token() != token_type::end_of_input)) - { - return sax->parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - parse_error::create(101, m_lexer.get_position(), - exception_message(token_type::end_of_input, "value"))); - } - - return result; - } - - private: - template <typename SAX> - bool sax_parse_internal(SAX* sax) - { - // stack to remember the hierarchy of structured values we are parsing - // true = array; false = object - std::vector<bool> states; - // value to avoid a goto (see comment where set to true) - bool skip_to_state_evaluation = false; - - while (true) - { - if (not skip_to_state_evaluation) - { - // invariant: get_token() was called before each iteration - switch (last_token) - { - case token_type::begin_object: - { - if (JSON_UNLIKELY(not sax->start_object(std::size_t(-1)))) - { - return false; - } - - // closing } -> we are done - if (get_token() == token_type::end_object) - { - if (JSON_UNLIKELY(not sax->end_object())) - { - return false; - } - break; - } - - // parse key - if (JSON_UNLIKELY(last_token != token_type::value_string)) - { - return sax->parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - parse_error::create(101, m_lexer.get_position(), - exception_message(token_type::value_string, "object key"))); - } - if (JSON_UNLIKELY(not sax->key(m_lexer.get_string()))) - { - return false; - } - - // parse separator (:) - if (JSON_UNLIKELY(get_token() != token_type::name_separator)) - { - return sax->parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - parse_error::create(101, m_lexer.get_position(), - exception_message(token_type::name_separator, "object separator"))); - } - - // remember we are now inside an object - states.push_back(false); - - // parse values - get_token(); - continue; - } - - case token_type::begin_array: - { - if (JSON_UNLIKELY(not sax->start_array(std::size_t(-1)))) - { - return false; - } - - // closing ] -> we are done - if (get_token() == token_type::end_array) - { - if (JSON_UNLIKELY(not sax->end_array())) - { - return false; - } - break; - } - - // remember we are now inside an array - states.push_back(true); - - // parse values (no need to call get_token) - continue; - } - - case token_type::value_float: - { - const auto res = m_lexer.get_number_float(); - - if (JSON_UNLIKELY(not std::isfinite(res))) - { - return sax->parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - out_of_range::create(406, "number overflow parsing '" + m_lexer.get_token_string() + "'")); - } - else - { - if (JSON_UNLIKELY(not sax->number_float(res, m_lexer.get_string()))) - { - return false; - } - break; - } - } - - case token_type::literal_false: - { - if (JSON_UNLIKELY(not sax->boolean(false))) - { - return false; - } - break; - } - - case token_type::literal_null: - { - if (JSON_UNLIKELY(not sax->null())) - { - return false; - } - break; - } - - case token_type::literal_true: - { - if (JSON_UNLIKELY(not sax->boolean(true))) - { - return false; - } - break; - } - - case token_type::value_integer: - { - if (JSON_UNLIKELY(not sax->number_integer(m_lexer.get_number_integer()))) - { - return false; - } - break; - } - - case token_type::value_string: - { - if (JSON_UNLIKELY(not sax->string(m_lexer.get_string()))) - { - return false; - } - break; - } - - case token_type::value_unsigned: - { - if (JSON_UNLIKELY(not sax->number_unsigned(m_lexer.get_number_unsigned()))) - { - return false; - } - break; - } - - case token_type::parse_error: - { - // using "uninitialized" to avoid "expected" message - return sax->parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - parse_error::create(101, m_lexer.get_position(), - exception_message(token_type::uninitialized, "value"))); - } - - default: // the last token was unexpected - { - return sax->parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - parse_error::create(101, m_lexer.get_position(), - exception_message(token_type::literal_or_value, "value"))); - } - } - } - else - { - skip_to_state_evaluation = false; - } - - // we reached this line after we successfully parsed a value - if (states.empty()) - { - // empty stack: we reached the end of the hierarchy: done - return true; - } - else - { - if (states.back()) // array - { - // comma -> next value - if (get_token() == token_type::value_separator) - { - // parse a new value - get_token(); - continue; - } - - // closing ] - if (JSON_LIKELY(last_token == token_type::end_array)) - { - if (JSON_UNLIKELY(not sax->end_array())) - { - return false; - } - - // We are done with this array. Before we can parse a - // new value, we need to evaluate the new state first. - // By setting skip_to_state_evaluation to false, we - // are effectively jumping to the beginning of this if. - assert(not states.empty()); - states.pop_back(); - skip_to_state_evaluation = true; - continue; - } - else - { - return sax->parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - parse_error::create(101, m_lexer.get_position(), - exception_message(token_type::end_array, "array"))); - } - } - else // object - { - // comma -> next value - if (get_token() == token_type::value_separator) - { - // parse key - if (JSON_UNLIKELY(get_token() != token_type::value_string)) - { - return sax->parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - parse_error::create(101, m_lexer.get_position(), - exception_message(token_type::value_string, "object key"))); - } - else - { - if (JSON_UNLIKELY(not sax->key(m_lexer.get_string()))) - { - return false; - } - } - - // parse separator (:) - if (JSON_UNLIKELY(get_token() != token_type::name_separator)) - { - return sax->parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - parse_error::create(101, m_lexer.get_position(), - exception_message(token_type::name_separator, "object separator"))); - } - - // parse values - get_token(); - continue; - } - - // closing } - if (JSON_LIKELY(last_token == token_type::end_object)) - { - if (JSON_UNLIKELY(not sax->end_object())) - { - return false; - } - - // We are done with this object. Before we can parse a - // new value, we need to evaluate the new state first. - // By setting skip_to_state_evaluation to false, we - // are effectively jumping to the beginning of this if. - assert(not states.empty()); - states.pop_back(); - skip_to_state_evaluation = true; - continue; - } - else - { - return sax->parse_error(m_lexer.get_position(), - m_lexer.get_token_string(), - parse_error::create(101, m_lexer.get_position(), - exception_message(token_type::end_object, "object"))); - } - } - } - } - } - - /// get next token from lexer - token_type get_token() - { - return (last_token = m_lexer.scan()); - } - - std::string exception_message(const token_type expected, const std::string& context) - { - std::string error_msg = "syntax error "; - - if (not context.empty()) - { - error_msg += "while parsing " + context + " "; - } - - error_msg += "- "; - - if (last_token == token_type::parse_error) - { - error_msg += std::string(m_lexer.get_error_message()) + "; last read: '" + - m_lexer.get_token_string() + "'"; - } - else - { - error_msg += "unexpected " + std::string(lexer_t::token_type_name(last_token)); - } - - if (expected != token_type::uninitialized) - { - error_msg += "; expected " + std::string(lexer_t::token_type_name(expected)); - } - - return error_msg; - } - - private: - /// callback function - const parser_callback_t callback = nullptr; - /// the type of the last read token - token_type last_token = token_type::uninitialized; - /// the lexer - lexer_t m_lexer; - /// whether to throw exceptions in case of errors - const bool allow_exceptions = true; -}; -} // namespace detail -} // namespace nlohmann |