json.hpp File Reference

#include <string>
#include <nlohmann/json.hpp>

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Typedefs
using	fable::Json = nlohmann::json
using	fable::JsonPointer = Json::json_pointer
using	fable::JsonType = Json::value_t

Functions
std::string	fable::to_string (JsonType)
template<typename InputType >
Json	fable::parse_json (InputType &&input)

Variables
bool	fable::NLOHMANN_JSON_ALLOW_COMMENTS = PARSE_JSON_WITH_COMMENTS
bool	fable::NLOHMANN_JSON_USE_EXCEPTIONS = PARSE_JSON_USE_EXCEPTIONS

Detailed Description

This file provides the basic fable::Json type used to represent JSON data. For functions and other to_json functions, see files in the json/ directory.

Typedef Documentation

Json

using fable::Json = typedef nlohmann::json

The Json type maps to nlohmann::json.

Bringing it into the fable namespace makes it much easier to use. Making it start with capital J prevents any collision with builtins. Because it is a using statement, standard nlohmann::json constructs can be used, such as to_json and from_json.

Examples:

/home/docs/checkouts/readthedocs.org/user_builds/cloe/checkouts/v0.20.0/fable/include/fable/schema.hpp, /home/docs/checkouts/readthedocs.org/user_builds/cloe/checkouts/v0.20.0/fable/include/fable/schema/interface.hpp, and /home/docs/checkouts/readthedocs.org/user_builds/cloe/checkouts/v0.20.0/fable/include/fable/schema/struct.hpp.

JsonPointer

using fable::JsonPointer = typedef Json::json_pointer

The JsonPointer type maps to nlohmann::json_pointer.

This makes it easier to talk/write about operations that deal with JSON pointers.

JsonType

using fable::JsonType = typedef Json::value_t

The JsonType type maps to nlohmann::json::value_t.

This makes it easier to talk/write about operations that deal on the underlying type that is stored in a Json value.

Examples:

/home/docs/checkouts/readthedocs.org/user_builds/cloe/checkouts/v0.20.0/fable/include/fable/schema.hpp, and /home/docs/checkouts/readthedocs.org/user_builds/cloe/checkouts/v0.20.0/fable/include/fable/schema/interface.hpp.

Function Documentation

parse_json()

template<typename InputType >

Json fable::parse_json ( InputType &&  input )

inline

Return the result of Json::parse, with the options to use exceptions and allow comments as set in this library, from NLOHMANN_JSON_USE_EXCEPTIONS and NLOHMANN_JSON_ALLOW_COMMENTS.

See the documentation on each of these global variables for more details.

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to_string()

std::string fable::to_string

(

JsonType

type

)

Return a string representation of a JSON type.

The returned string is one of the following values:

null
object
array
boolean
float
integer
unsigned
string
unknown

Variable Documentation

NLOHMANN_JSON_ALLOW_COMMENTS

bool fable::NLOHMANN_JSON_ALLOW_COMMENTS = PARSE_JSON_WITH_COMMENTS

When parsing JSON from fable, should comments be allowed or lead to an exception? Value is controlled by PARSE_JSON_WITH_COMMENTS define. Default value is true.

This does not automatically apply to use of Json::parse. Instead you should use the parse_json helper function defined in this file.

NLOHMANN_JSON_USE_EXCEPTIONS

bool fable::NLOHMANN_JSON_USE_EXCEPTIONS = PARSE_JSON_USE_EXCEPTIONS

When parsing JSON from fable, should exceptions be used? Default value is set by PARSE_JSON_WITH_COMMENTS define.

This is here for completeness. The fable library will not work correctly if exceptions are disabled, so this should always be set to true.