diff options
Diffstat (limited to 'libbutl/json/parser.hxx')
| -rw-r--r-- | libbutl/json/parser.hxx | 299 |
1 files changed, 298 insertions, 1 deletions
diff --git a/libbutl/json/parser.hxx b/libbutl/json/parser.hxx index 241ca46..95d9c4e 100644 --- a/libbutl/json/parser.hxx +++ b/libbutl/json/parser.hxx @@ -172,6 +172,9 @@ namespace butl parser& operator= (parser&&) = delete; parser& operator= (const parser&) = delete; + // Event iteration. + // + // Return the next event or nullopt if end of input is reached. // // In the single-value parsing mode (default) the parsing code could @@ -259,7 +262,8 @@ namespace butl optional<event> peek (); - // Event data. + + // Event data access. // // Return the object member name. @@ -295,6 +299,299 @@ namespace butl std::pair<const char*, std::size_t> data () const {return std::make_pair (raw_s_, raw_n_);} + + // Higher-level API suitable for parsing specific JSON vocabularies. + // + // The API summary: + // + // void next_expect (event); + // bool next_expect (event primary, event secondary); + // + // void next_expect_name (string name, bool skip_unknown = false); + // + // std::string& next_expect_string (); + // T next_expect_string<T> (); + // std::string& next_expect_number (); + // T next_expect_number<T> (); + // std::string& next_expect_boolean (); + // T next_expect_boolean<T>(); + // + // std::string* next_expect_string_null (); + // optional<T> next_expect_string_null<T> (); + // std::string* next_expect_number_null (); + // optional<T> next_expect_number_null<T> (); + // std::string* next_expect_boolean_null (); + // optional<T> next_expect_boolean_null<T>(); + // + // std::string& next_expect_member_string (string name, bool = false); + // T next_expect_member_string<T> (string name, bool = false); + // std::string& next_expect_member_number (string name, bool = false); + // T next_expect_member_number<T> (string name, bool = false); + // std::string& next_expect_member_boolean (string name, bool = false); + // T next_expect_member_boolean<T>(string name, bool = false); + // + // std::string* next_expect_member_string_null (string, bool = false); + // optional<T> next_expect_member_string_null<T> (string, bool = false); + // std::string* next_expect_member_number_null (string, bool = false); + // optional<T> next_expect_member_number_null<T> (string, bool = false); + // std::string* next_expect_member_boolean_null (string, bool = false); + // optional<T> next_expect_member_boolean_null<T>(string, bool = false); + // + // void next_expect_member_object (string name, bool = false); + // bool next_expect_member_object_null(string name, bool = false); + // + // void next_expect_member_array (string name, bool = false); + // bool next_expect_member_array_null(string name, bool = false); + // + // void next_expect_value_skip(); + + // Get the next event and make sure that it's what's expected: primary + // or, if specified, secondary event. If it is not either, then throw + // invalid_json_input with appropriate description. Return true if it is + // primary. + // + // The secondary expected event is primarily useful for handling + // optional members. For example: + // + // while (p.next_expect (event::name, event::end_object)) + // { + // // Handle object member. + // } + // + // Or homogeneous arrays: + // + // while (p.next_expect (event::string, event::end_array)) + // { + // // Handle array element. + // } + // + // Or values that can be null: + // + // if (p.next_expect (event::begin_object, event::null)) + // { + // // Parse object. + // } + // + bool + next_expect (event primary, optional<event> secondary = nullopt); + + // Get the next event and make sure it is event::name and the object + // member matches the specified name. If either is not, then throw + // invalid_json_input with appropriate description. If skip_unknown is + // true, then skip over unknown member names until a match is found. + // + void + next_expect_name (const char* name, bool skip_unknown = false); + + void + next_expect_name (const std::string&, bool = false); + + // Get the next event and make sure it is event::<type> returning its + // value similar to the value() functions. If it is not, then throw + // invalid_json_input with appropriate description. + // + std::string& + next_expect_string (); + + template <typename T> + T + next_expect_string (); + + std::string& + next_expect_number (); + + template <typename T> + T + next_expect_number (); + + std::string& + next_expect_boolean (); + + template <typename T> + T + next_expect_boolean (); + + // Similar to next_expect_<type>() but in addition to event::<type> also + // allow event::null, in which case returning no value. + // + std::string* + next_expect_string_null (); + + template <typename T> + optional<T> + next_expect_string_null (); + + std::string* + next_expect_number_null (); + + template <typename T> + optional<T> + next_expect_number_null (); + + std::string* + next_expect_boolean_null (); + + template <typename T> + optional<T> + next_expect_boolean_null (); + + // Call next_expect_name() followed by next_expect_<type>[_null]() + // returning its result. In other words, parse the entire object member + // with the specifed name and of type <type>, returning its value. + + // next_expect_member_string() + // + std::string& + next_expect_member_string (const char* name, bool skip_unknown = false); + + std::string& + next_expect_member_string (const std::string&, bool = false); + + template <typename T> + T + next_expect_member_string (const char*, bool = false); + + template <typename T> + T + next_expect_member_string (const std::string&, bool = false); + + // next_expect_member_number() + // + std::string& + next_expect_member_number (const char* name, bool skip_unknown = false); + + std::string& + next_expect_member_number (const std::string&, bool = false); + + template <typename T> + T + next_expect_member_number (const char*, bool = false); + + template <typename T> + T + next_expect_member_number (const std::string&, bool = false); + + // next_expect_member_boolean() + // + std::string& + next_expect_member_boolean (const char* name, bool skip_unknown = false); + + std::string& + next_expect_member_boolean (const std::string&, bool = false); + + template <typename T> + T + next_expect_member_boolean (const char*, bool = false); + + template <typename T> + T + next_expect_member_boolean (const std::string&, bool = false); + + // next_expect_member_string_null() + // + std::string* + next_expect_member_string_null (const char*, bool = false); + + std::string* + next_expect_member_string_null (const std::string&, bool = false); + + template <typename T> + optional<T> + next_expect_member_string_null (const char*, bool = false); + + template <typename T> + optional<T> + next_expect_member_string_null (const std::string&, bool = false); + + // next_expect_member_number_null() + // + std::string* + next_expect_member_number_null (const char*, bool = false); + + std::string* + next_expect_member_number_null (const std::string&, bool = false); + + template <typename T> + optional<T> + next_expect_member_number_null (const char*, bool = false); + + template <typename T> + optional<T> + next_expect_member_number_null (const std::string&, bool = false); + + // next_expect_member_boolean_null() + // + std::string* + next_expect_member_boolean_null (const char*, bool = false); + + std::string* + next_expect_member_boolean_null (const std::string&, bool = false); + + template <typename T> + optional<T> + next_expect_member_boolean_null (const char*, bool = false); + + template <typename T> + optional<T> + next_expect_member_boolean_null (const std::string&, bool = false); + + // Call next_expect_name() followed by next_expect(event::begin_object). + // In the _null version also allow event::null, in which case return + // false. + // + void + next_expect_member_object (const char* name, bool skip_unknown = false); + + void + next_expect_member_object (const std::string&, bool = false); + + bool + next_expect_member_object_null (const char*, bool = false); + + bool + next_expect_member_object_null (const std::string&, bool = false); + + // Call next_expect_name() followed by next_expect(event::begin_array). + // In the _null version also allow event::null, in which case return + // false. + // + void + next_expect_member_array (const char* name, bool skip_unknown = false); + + void + next_expect_member_array (const std::string&, bool = false); + + bool + next_expect_member_array_null (const char*, bool = false); + + bool + next_expect_member_array_null (const std::string&, bool = false); + + // Get the next event and make sure it is the beginning of a value + // (begin_object, begin_array, string, number, boolean, null). If it is + // not, then throw invalid_json_input with appropriate description. + // Otherwise, skip until the end of the value, recursively in case of + // object and array. + // + // This function is primarily useful for skipping unknown object + // members, for example: + // + // while (p.next_expect (event::name, event::end_object)) + // { + // if (p.name () == "known") + // { + // // Handle known member. + // } + // else + // p.next_expect_value_skip (); + // } + // + void + next_expect_value_skip (); + + // Parsing location. + // + // Return the line number (1-based) corresponding to the most recently // parsed event or 0 if nothing has been parsed yet. // |