Better argument validation

[jansson.git] / doc / apiref.rst

diff --git a/doc/apiref.rst b/doc/apiref.rst
index 57b5e31..ea38343 100644 (file)
--- a/doc/apiref.rst
+++ b/doc/apiref.rst
@@ -41,6 +41,12 @@ Objects of :ctype:`json_t` are always used through a pointer. There
 are APIs for querying the type, manipulating the reference count, and
 for constructing and manipulating values of different types.
 
 are APIs for querying the type, manipulating the reference count, and
 for constructing and manipulating values of different types.
 

+Unless noted otherwise, all API functions return an error value if an
+error occurs. Depending on the function's signature, the error value
+is either *NULL* or -1. Invalid arguments or invalid input are
+apparent sources for errors. Memory allocation and I/O operations may
+also cause errors.
+

 
 Type
 ----
 
 Type
 ----


@@ -80,8 +86,8 @@ functions:
 .. cfunction:: int json_typeof(const json_t *json)
 
    Return the type of the JSON value (a :ctype:`json_type` cast to
 .. cfunction:: int json_typeof(const json_t *json)
 
    Return the type of the JSON value (a :ctype:`json_type` cast to

-   :ctype:`int`). This function is actually implemented as a macro for
-   speed.
+   :ctype:`int`). *json* MUST NOT be *NULL*. This function is actually
+   implemented as a macro for speed.

 
 .. cfunction:: json_is_object(const json_t *json)
                json_is_array(const json_t *json)
 
 .. cfunction:: json_is_object(const json_t *json)
                json_is_array(const json_t *json)


@@ -121,7 +127,7 @@ The following functions are used to manipulate the reference count.
 
 .. cfunction:: json_t *json_incref(json_t *json)
 
 
 .. cfunction:: json_t *json_incref(json_t *json)
 

-   Increment the reference count of *json*.
+   Increment the reference count of *json*. Returns *json*.

 
 .. cfunction:: void json_decref(json_t *json)
 
 
 .. cfunction:: void json_decref(json_t *json)