update docs with namedtuple encoding to JSON object

CHANGES.txt

-Version 2.1.7 released 2011-XX-XX
+Version 2.2.0 released 2011-XX-XX
 
@@ -2,4 +2,7 @@
 
+* namedtuple (or other tuple subclasses with _asdict methods) are now
+  encoded as JSON objects rather than arrays.
+  https://github.com/simplejson/simplejson/pull/6
 * JSONDecodeError is now raised instead of ValueError when a document
   ends with an opening quote and the C speedups are in use.
   https://github.com/simplejson/simplejson/issues/15

index.rst

@@ -399,7 +399,7 @@
    +-------------------+---------------+
    | Python            | JSON          |
    +===================+===============+
-   | dict              | object        |
+   | dict, namedtuple  | object        |
    +-------------------+---------------+
    | list, tuple       | array         |
    +-------------------+---------------+
@@ -414,6 +414,9 @@
    | None              | null          |
    +-------------------+---------------+
 
+   .. versionchanged:: 2.2.0
+      Changed *namedtuple* encoding from JSON array to object.
+
    To extend this to recognize other objects, subclass and implement a
    :meth:`default` method with another method that returns a serializable object
    for ``o`` if possible, otherwise it should call the superclass implementation

simplejson/encoder.py

@@ -80,7 +80,7 @@
     +-------------------+---------------+
     | Python            | JSON          |
     +===================+===============+
-    | dict              | object        |
+    | dict, namedtuple  | object        |
     +-------------------+---------------+
     | list, tuple       | array         |
     +-------------------+---------------+