in each source file.
-All constants are prefixed ``JSON_`` and other identifiers with
-``json_``. Type names are suffixed with ``_t`` and ``typedef``\ 'd so
-that the ``struct`` keyword need not be used.
+All constants are prefixed with ``JSON_`` (except for those describing
+the library version, prefixed with ``JANSSON_``). Other identifiers
+are prefixed with ``json_``. Type names are suffixed with ``_t`` and
+``typedef``\ 'd so that the ``struct`` keyword need not be used.
+
+
+Library Version
+===============
+
+The Jansson version is of the form *A.B.C*, where *A* is the major
+version, *B* is the minor version and *C* is the micro version. If the
+micro version is zero, it's omitted from the version string, i.e. the
+version string is just *A.B*.
+
+When a new release only fixes bugs and doesn't add new features or
+functionality, the micro version is incremented. When new features are
+added in a backwards compatible way, the minor version is incremented
+and the micro version is set to zero. When there are backwards
+incompatible changes, the major version is incremented and others are
+set to zero.
+
+The following preprocessor constants specify the current version of
+the library:
+
+``JANSSON_VERSION_MAJOR``, ``JANSSON_VERSION_MINOR``, ``JANSSON_VERSION_MICRO``
+ Integers specifying the major, minor and micro versions,
+ respectively.
+
+``JANSSON_VERSION``
+ A string representation of the current version, e.g. ``"1.2.1"`` or
+ ``"1.3"``.
+
+``JANSSON_VERSION_HEX``
+ A 3-byte hexadecimal representation of the version, e.g.
+ ``0x010201`` for version 1.2.1 and ``0x010300`` for version 1.3.
+ This is useful in numeric comparisions, e.g.::
+
+ #if JANSSON_VERSION_HEX >= 0x010300
+ /* Code specific to version 1.3 and above */
+ #endif
Value Representation
to the JSON specification. It explains many design decisions that
affect especially the behavior of the decoder.
-.. type:: json_error_t
-
- This opaque structure is used to return information on errors from
- the decoding functions. See below for more discussion on error
- reporting.
-
-The following functions perform the JSON decoding:
-
-.. function:: json_t *json_loads(const char *input, size_t flags, json_error_t **error)
+.. function:: json_t *json_loads(const char *input, size_t flags, json_error_t *error)
.. refcounting:: new
Decodes the JSON string *input* and returns the array or object it
- contains, or *NULL* on error. If *error* is non-*NULL*, it's used
- to return error information. See below for more discussion on error
- reporting. *flags* is currently unused, and should be set to 0.
+ contains, or *NULL* on error, in which case *error* is filled with
+ information about the error. See above for discussion on the
+ *error* parameter. *flags* is currently unused, and should be set
+ to 0.
-.. function:: json_t *json_loadf(FILE *input, size_t flags, json_error_t **error)
+.. function:: json_t *json_loadf(FILE *input, size_t flags, json_error_t *error)
.. refcounting:: new
Decodes the JSON text in stream *input* and returns the array or
- object it contains, or *NULL* on error. If *error* is non-*NULL*,
- it's used to return error information. See below for more
- discussion on error reporting. *flags* is currently unused, and
- should be set to 0.
+ object it contains, or *NULL* on error, in which case *error* is
+ filled with information about the error. See above for discussion
+ on the *error* parameter. *flags* is currently unused, and should
+ be set to 0.
-.. function:: json_t *json_load_file(const char *path, size_t flags, json_error_t **error)
+.. function:: json_t *json_load_file(const char *path, size_t flags, json_error_t *error)
.. refcounting:: new
Decodes the JSON text in file *path* and returns the array or
- object it contains, or *NULL* on error. If *error* is non-*NULL*,
- it's used to return error information. See below for more
- discussion on error reporting. *flags* is currently unused, and
- should be set to 0.
-
-
-The :type:`json_error_t` parameter, that all decoding function accept
-as their last parameter, is used to return information on decoding
-errors to the caller. It is used by having a ``json_error_t *``
-variable and passing a pointer to this variable to a decoding
-function. Example::
-
- int main() {
- json_t *json;
- json_error_t *error;
-
- json = json_load_file("/path/to/file.json", 0, &error);
- if(!json) {
- /* the error variable contains error information */
- fprintf(stderr, "Decoding error occured on line %d: %s\n", json_error_line(error), json_error_msg(error));
- free(error);
- }
-
- /* ... */
- }
+ object it contains, or *NULL* on error, in which case *error* is
+ filled with information about the error. See above for discussion
+ on the *error* parameter. *flags* is currently unused, and should
+ be set to 0.
-Note that **the caller must free the error structure** after use if a
-decoding error occurs. If decoding is succesfully finished, *error* is
-simply set to *NULL* by the decoding function.
+.. type:: json_error_t
-All decoding functions also accept *NULL* as the :type:`json_error_t`
-pointer, in which case no error information is returned to the caller.
-Example::
+ This data structure is used to return information on decoding
+ errors from the decoding functions.
- int main() {
- json_t *json;
+ .. member:: const char *text
- json = json_load_file("/path/to/file.json", 0, NULL);
- if(!json) {
- /* A decoding error occured but no error information is available */
- }
+ The error message (in UTF-8), or an empty string if a message is
+ not available.
- /* ... */
- }
+ .. member:: int line
+
+ The line number on which the error occurred, or -1 if this
+ information is not available.
+
+ .. member:: int column
+
+ The character column on which the error occurred, or -1 if this
+ information is not available.
+
+ .. member:: const char *source
+
+ Source of the error. This is (a part of) the file name when
+ using :func:`json_load_file()`, or a special identifier in angle
+ brackets otherwise (e.g. ``<string>``).
-:type:`json_error_t` is totally opaque and must be queried using the
-following functions:
+ The normal use of :type:`json_error_t` is to allocate it on the
+ stack, and pass a pointer to a decoding function. Example::
-.. function:: const char *json_error_msg(const json_error_t *error)
+ int main() {
+ json_t *json;
+ json_error_t error;
- Return a pointer to an UTF-8 encoded string that describes the
- error in human-readable text, or *NULL* if *error* is *NULL*.
+ json = json_load_file("/path/to/file.json", 0, &error);
+ if(!json) {
+ /* the error variable contains error information */
+ }
+ ...
+ }
-.. function:: int json_error_line(const json_error_t *error)
+ Also note that if the decoding succeeded (``json != NULL`` in the
+ above example), the contents of ``error`` are unspecified.
- Return the line numer on which the error occurred, or -1 if this
- information is not available or if *error* is *NULL*.
+ All decoding functions also accept *NULL* as the
+ :type:`json_error_t` pointer, in which case no error information
+ is returned to the caller.
Equality