Json library

The library provides methods for working with the json format.

The document keeps a list of tokens and adds new tokens as needed.

When a document is destroyed, all memory associated with it, all tokens, are released.

Calling the json_stringify_detach method detaches the pointer to a string within the document, so the returned pointer to the string must be manually freed with the free function.

jsondoc_t* json_init();

Creating a json document.

Parameters
No

Return value
Pointer to allocated memory of type jsondoc_t.

int json_parse(jsondoc_t* document, const char* string);

Parsing a string and generating a json document.

Parameters
document - pointer to the document to write.
string - source string to parse.

Return value
Nonzero if the parse succeeded, zero otherwise.

void json_free(jsondoc_t* document);

Freeing the memory of the json document, including all tokens.

Parameters
document - document pointer.

Return value
No

void json_token_reset(jsontok_t* token);

Reset the internal data of the token.

Parameters
token - pointer to token.

Return value
No

jsontok_t* json_root(jsondoc_t* document);

Retrieve the document's root token.

Parameters
document - document pointer.

Return value
A pointer to a token.

int json_ok(jsondoc_t* document);

Checking the correctness of the json document.

Parameters
document - document pointer.

Return value
Nonzero if the document is valid, zero otherwise.

const char* json_error(jsondoc_t* document);

Output a string with an error message.

Parameters
document - document pointer.

Return value
If successful, returns a constant pointer to the beginning of the string.
Returns a null pointer on error.

int json_bool(const jsontok_t* token);
int json_int(const jsontok_t* token);
double json_double(const jsontok_t* token);
long long json_llong(const jsontok_t* token);
const char *json_string(const jsontok_t* token);
unsigned int json_uint(const jsontok_t* token);

Extracting a value from a token.

Parameters
token - pointer to token.

Return value
If successful, returns a value depending on the type.

int json_is_bool(const jsontok_t* token);
int json_is_null(const jsontok_t* token);
int json_is_string(const jsontok_t* token);
int json_is_llong(const jsontok_t* token);
int json_is_int(const jsontok_t* token);
int json_is_uint(const jsontok_t* token);
int json_is_double(const jsontok_t* token);
int json_is_object(const jsontok_t* token);
int json_is_array(const jsontok_t* token);

Checking the type of the value in the token.

Parameters
token - pointer to token.

Return value
Nonzero if the expected value type, zero otherwise.

jsontok_t* json_create_bool(jsondoc_t* document, int bool);
jsontok_t* json_create_null(jsondoc_t* document);
jsontok_t* json_create_string(jsondoc_t* document, const char* string);
jsontok_t* json_create_llong(jsondoc_t* document, long long number);
jsontok_t* json_create_int(jsondoc_t* document, int number);
jsontok_t* json_create_uint(jsondoc_t* document, unsigned int number);
jsontok_t* json_create_double(jsondoc_t* document, double number);
jsontok_t* json_create_object(jsondoc_t* document);
jsontok_t* json_create_array(jsondoc_t* document);

Create a new token with a type for the document.

Parameters
document - document pointer.

Return value
pointer to token.

int json_array_prepend(jsontok_t* array, jsontok_t* token);
int json_array_append(jsontok_t* array, jsontok_t* token);
int json_array_append_to(jsontok_t* array, int index, jsontok_t* token);
int json_array_erase(jsontok_t* array, int index, int count);
int json_array_clear(jsontok_t* array);
int json_array_size(const jsontok_t* array);
jsontok_t* json_array_get(const jsontok_t* array, int index);

Array management methods.

Parameters
array - pointer to the array to write.
token - pointer to token to insert.
index - element position.
count - the number of elements.

Return value
If successful, returns a value depending on the type.

int json_object_set(jsontok_t* object, const char* key, jsontok_t* token);
jsontok_t* json_object_get(const jsontok_t* object, const char* key);
int json_object_remove(jsontok_t* object, const char* key);
int json_object_size(const jsontok_t* object);
int json_object_clear(jsontok_t* object);

Object management methods.

Parameters
object - pointer to the object to write.
key - pointer to a string with the name of the property.
token - pointer to the token to insert.

Return value
If successful, returns a value depending on the type.

void json_token_set_bool(jsontok_t* token, int bool);
void json_token_set_null(jsontok_t* token);
void json_token_set_string(jsontok_t* token, const char* string);
void json_token_set_llong(jsontok_t* token, long long number);
void json_token_set_int(jsontok_t* token, int number);
void json_token_set_uint(jsontok_t* token, unsigned int number);
void json_token_set_double(jsontok_t* token, double number);
void json_token_set_object(jsontok_t* token, jsontok_t* object);
void json_token_set_array(jsontok_t* token, jsontok_t* array);

Setting a new value for the token.

Parameters
token - a pointer to the token to insert.

Return value
No

jsonit_t json_init_it(const jsontok_t* token);
int json_end_it(const jsonit_t* iterator);
const void* json_it_key(const jsonit_t* iterator);
jsontok_t* json_it_value(const jsonit_t* iterator);
jsonit_t json_next_it(jsonit_t* iterator);
void json_it_erase(jsonit_t* iterator);

Iterator control when traversing an object or array.

Parameters
token - pointer to a token to initialize the iterator. iterator - pointer to an iterator.

Return value
If successful, returns a value depending on the type.

const char* json_stringify(jsondoc_t* document);

Formation of a string from a json document.

Parameters
document - document pointer.

Return value
If successful, returns a constant pointer to the beginning of the string.
Returns a null pointer on error.

char* json_stringify_detach(jsondoc_t* document);

Forming a string from a json document.
You must manually free the memory when you are done with the string.

Parameters
document - document pointer.

Return value
If successful, returns a pointer to the beginning of the string.
Returns a null pointer on error.

Json library ​

Json library