LLVM: llvm::json::Value Class Reference (original) (raw)

A Value is an JSON value of unknown type. More...

#include "[llvm/Support/JSON.h](JSON%5F8h%5Fsource.html)"

Public Types
enum	Kind { Null, Boolean, Number, String, Array, Object }

Public Member Functions
	Value (const Value &M)
	Value (Value &&M)
LLVM_ABI	Value (std::initializer_list< Value > Elements)
	Value (json::Array &&Elements)
template
	Value (const std::vector< Elt > &C)
	Value (json::Object &&Properties)
template
	Value (const std::map< std::string, Elt > &C)
	Value (std::string V)
	Value (const llvm::SmallVectorImpl< char > &V)
	Value (const llvm::formatv_object_base &V)
	Value (StringRef V)
	Value (const char *V)
	Value (std::nullptr_t)
template<typename T, typename = std::enable_if_t<std::is_same_v<T, bool>>, bool = false>
	Value (T B)
template<typename T, typename = std::enable_if_t<is_uint_64_bit_v>>
	Value (T V)
template<typename T, typename = std::enable_if_t<std::is_integral_v>, typename = std::enable_if_t<!std::is_same_v<T, bool>>, typename = std::enable_if_t<!is_uint_64_bit_v>>
	Value (T I)
template<typename T, typename = std::enable_if_t<std::is_floating_point_v>, double * = nullptr>
	Value (T D)
template<typename T, typename = std::enable_if_t< std::is_same_v<Value, decltype(toJSON((const T )nullptr))>>, Value * = nullptr>
	Value (const T &V)
Value &	operator= (const Value &M)
Value &	operator= (Value &&M)
	~Value ()
Kind	kind () const
std::optional< std::nullptr_t >	getAsNull () const
std::optional< bool >	getAsBoolean () const
std::optional< double >	getAsNumber () const
std::optional< int64_t >	getAsInteger () const
std::optional< uint64_t >	getAsUINT64 () const
std::optional< llvm::StringRef >	getAsString () const
const json::Object *	getAsObject () const
json::Object *	getAsObject ()
const json::Array *	getAsArray () const
json::Array *	getAsArray ()
LLVM_ABI void	print (llvm::raw_ostream &OS) const
LLVM_DUMP_METHOD void	dump () const

A Value is an JSON value of unknown type.

They can be copied, but should generally be moved.

=== Composing values ===

You can implicitly construct Values from:

strings: std::string, SmallString, formatv, StringRef, char* (char*, and StringRef are references, not copies!)
numbers
booleans
null: nullptr
arrays: {"foo", 42.0, false}
serializable things: types with toJSON(const T&)->Value, found by ADL

They can also be constructed from object/array helpers:

json::Object is a type like map<ObjectKey, Value>
json::Array is a type like vector These can be list-initialized, or used to build up collections in a loop. json::ary(Collection) converts all items in a collection to Values.

=== Inspecting values ===

Each Value is one of the JSON kinds: null (nullptr_t) boolean (bool) number (double, int64 or uint64) string (StringRef) array (json::Array) object (json::Object)

The kind can be queried directly, or implicitly via the typed accessors: if (std::optional S = E.getAsString() assert(E.kind() == Value::String);

Array and Object also have typed indexing accessors for easy traversal: Expected E = parse(R"( {"options": {"font": "sans-serif"}} )"); if (Object* O = E->getAsObject()) if (Object* Opts = O->getObject("options")) if (std::optional Font = Opts->getString("font")) assert(Opts->at("font").kind() == Value::String);

=== Converting JSON values to C++ types ===

The convention is to have a deserializer function findable via ADL: fromJSON(const json::Value&, T&, Path) -> bool

The return value indicates overall success, and [Path](classllvm%5F1%5F1json%5F1%5F1Path.html "A "cursor" marking a position within a Value.") is used for precise error reporting. (The Path::Root passed in at the top level fromJSON call captures any nested error and can render it in context). If conversion fails, fromJSON calls Path::report() and immediately returns. This ensures that the first fatal error survives.

Deserializers are provided for:

bool
int and int64_t
double
std::string
vector, where T is deserializable
map<string, T>, where T is deserializable
std::optional, where T is deserializable ObjectMapper can help writing fromJSON() functions for object types.

For conversion in the other direction, the serializer function is: toJSON(const T&) -> json::Value If this exists, then it also allows constructing Value from T, and can be used to serialize vector, map<string, T>, and std::optional.

=== Serialization ===

Values can be serialized to JSON: 1) raw_ostream << Value // Basic formatting. 2) raw_ostream << formatv("{0}", Value) // Basic formatting. 3) raw_ostream << formatv("{0:2}", Value) // Pretty-print with indent 2.

And parsed: Expected E = json::parse("[1, 2, null]"); assert(E && E->kind() == Value::Array);

Definition at line 291 of file JSON.h.

◆ Kind

Enumerator
Null
Boolean
Number	Number values can store both int64s and doubles at full precision, depending on what they were constructed/parsed from.
String
Array
Object

Definition at line 293 of file JSON.h.

◆ Value() [1/18]

llvm::json::Value::Value ( const Value & M)	inline

Definition at line 305 of file JSON.h.

References Value().

Referenced by operator=(), operator=(), operator==, Value(), Value(), Value(), Value(), Value(), Value(), Value(), and Value().

◆ Value() [2/18]

llvm::json::Value::Value ( Value && M)	inline

◆ Value() [3/18]

llvm::json::Value::Value	(	std::initializer_list< Value >	Elements	)

◆ Value() [4/18]

◆ Value() [5/18]

template

llvm::json::Value::Value ( const std::vector< Elt > & C)	inline

◆ Value() [6/18]

◆ Value() [7/18]

template

llvm::json::Value::Value ( const std::map< std::string, Elt > & C)	inline

◆ Value() [8/18]

llvm::json::Value::Value ( std::string V)	inline

◆ Value() [9/18]

◆ Value() [10/18]

◆ Value() [11/18]

llvm::json::Value::Value ( StringRef V)	inline

◆ Value() [12/18]

llvm::json::Value::Value ( const char * V)	inline

◆ Value() [13/18]

llvm::json::Value::Value ( std::nullptr_t )	inline

Definition at line 338 of file JSON.h.

◆ Value() [14/18]

template<typename T, typename = std::enable_if_t<std::is_same_v<T, bool>>, bool = false>

llvm::json::Value::Value ( T B)	inline

◆ Value() [15/18]

template<typename T, typename = std::enable_if_t<is_uint_64_bit_v>>

llvm::json::Value::Value ( T V)	inline

Definition at line 349 of file JSON.h.

References T.

◆ Value() [16/18]

template<typename T, typename = std::enable_if_t<std::is_integral_v>, typename = std::enable_if_t<!std::is_same_v<T, bool>>, typename = std::enable_if_t<!is_uint_64_bit_v>>

llvm::json::Value::Value ( T I)	inline

Definition at line 358 of file JSON.h.

References I, and T.

◆ Value() [17/18]

template<typename T, typename = std::enable_if_t<std::is_floating_point_v>, double * = nullptr>

llvm::json::Value::Value ( T D)	inline

◆ Value() [18/18]

template<typename T, typename = std::enable_if_t< std::is_same_v<Value, decltype(toJSON(*(const T *)nullptr))>>, Value * = nullptr>

llvm::json::Value::Value ( const T & V)	inline

Definition at line 373 of file JSON.h.

References T.

llvm::json::Value::~Value ( )	inline

Definition at line 385 of file JSON.h.

◆ dump()

◆ getAsArray() [1/2]

◆ getAsArray() [2/2]

◆ getAsBoolean()

std::optional< bool > llvm::json::Value::getAsBoolean ( ) const	inline

◆ getAsInteger()

std::optional< int64_t > llvm::json::Value::getAsInteger ( ) const	inline

◆ getAsNull()

std::optional< std::nullptr_t > llvm::json::Value::getAsNull ( ) const	inline

◆ getAsNumber()

std::optional< double > llvm::json::Value::getAsNumber ( ) const	inline

◆ getAsObject() [1/2]

◆ getAsObject() [2/2]

◆ getAsString()

std::optional< llvm::StringRef > llvm::json::Value::getAsString ( ) const	inline

◆ getAsUINT64()

std::optional< uint64_t > llvm::json::Value::getAsUINT64 ( ) const	inline

◆ kind()

Kind llvm::json::Value::kind ( ) const	inline

◆ operator=() [1/2]

◆ operator=() [2/2]

Value & llvm::json::Value::operator= ( Value && M)	inline