llvm::json::ObjectMapper Class Reference

Helper for mapping JSON objects onto protocol structs. More...

#include "llvm/Support/JSON.h"

Public Member Functions
	ObjectMapper (const Value &E, Path P)
	If O is not an object, this mapper is invalid and an error is reported.
	operator bool () const
	True if the expression is an object.
template<typename T>
bool	map (StringLiteral Prop, T &Out)
	Maps a property to a field.
template<typename T>
bool	map (StringLiteral Prop, std::optional< T > &Out)
	Maps a property to a field, if it exists.
template<typename T>
bool	mapOptional (StringLiteral Prop, T &Out)
	Maps a property to a field, if it exists.

Detailed Description

Helper for mapping JSON objects onto protocol structs.

Example:

bool fromJSON(const Value &E, MyStruct &R, Path P) {
  ObjectMapper O(E, P);
  // When returning false, error details were already reported.
  return O && O.map("mandatory_field", R.MandatoryField) &&
      O.mapOptional("optional_field", R.OptionalField);
}

Definition at line 860 of file JSON.h.

Constructor & Destructor Documentation

ObjectMapper()

llvm::json::ObjectMapper::ObjectMapper ( const Value & E, Path P )

inline

If O is not an object, this mapper is invalid and an error is reported.

Definition at line 863 of file JSON.h.

References E().

Member Function Documentation

map() [1/2]

template<typename T>

bool llvm::json::ObjectMapper::map ( StringLiteral Prop, std::optional< T > & Out )

inline

Maps a property to a field, if it exists.

If the property exists and is invalid, reports an error. (Optional requires special handling, because missing keys are OK).

Definition at line 885 of file JSON.h.

References assert(), E(), and llvm::json::fromJSON().

map() [2/2]

template<typename T>

bool llvm::json::ObjectMapper::map ( StringLiteral Prop, T & Out )

inline

Maps a property to a field.

If the property is missing or invalid, reports an error.

Definition at line 874 of file JSON.h.

References assert(), E(), llvm::json::fromJSON(), and T.

mapOptional()

template<typename T>

bool llvm::json::ObjectMapper::mapOptional ( StringLiteral Prop, T & Out )

inline

Maps a property to a field, if it exists.

If the property exists and is invalid, reports an error. If the property does not exist, Out is unchanged.

Definition at line 896 of file JSON.h.

References assert(), E(), llvm::json::fromJSON(), and T.

operator bool()

llvm::json::ObjectMapper::operator bool ( ) const

inline

True if the expression is an object.

Must be checked before calling map().

Definition at line 870 of file JSON.h.

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The documentation for this class was generated from the following file:

• include/llvm/Support/JSON.h