Patch #1436130: codecs.lookup() now returns a CodecInfo object (a subclass

of tuple) that provides incremental decoders and encoders (a way to use
stateful codecs without the stream API). Functions
codecs.getincrementaldecoder() and codecs.getincrementalencoder() have
been added.

1 files changed, 21 insertions, 12 deletions

diff --git a/Lib/encodings/__init__.py b/Lib/encodings/__init__.py
index ddaacb9..f8d2a2a 100644
--- a/Lib/encodings/__init__.py
+++ b/Lib/encodings/__init__.py
@@ -9,9 +9,10 @@
 
     Each codec module must export the following interface:
 
-    * getregentry() -> (encoder, decoder, stream_reader, stream_writer)
-    The getregentry() API must return callable objects which adhere to
-    the Python Codec Interface Standard.
+    * getregentry() -> codecs.CodecInfo object
+    The getregentry() API must a CodecInfo object with encoder, decoder,
+    incrementalencoder, incrementaldecoder, streamwriter and streamreader
+    atttributes which adhere to the Python Codec Interface Standard.
 
     In addition, a module may optionally also define the following
     APIs which are then used by the package's codec search function:
@@ -113,16 +114,24 @@ def search_function(encoding):
         return None
 
     # Now ask the module for the registry entry
-    entry = tuple(getregentry())
-    if len(entry) != 4:
-        raise CodecRegistryError,\
-              'module "%s" (%s) failed to register' % \
-              (mod.__name__, mod.__file__)
-    for obj in entry:
-        if not callable(obj):
+    entry = getregentry()
+    if not isinstance(entry, codecs.CodecInfo):
+        if not 4 <= len(entry) <= 7:
+             raise CodecRegistryError,\
+                  'module "%s" (%s) failed to register' % \
+                   (mod.__name__, mod.__file__)
+        if not callable(entry[0]) or \
+           not callable(entry[1]) or \
+           (entry[2] is not None and not callable(entry[2])) or \
+           (entry[3] is not None and not callable(entry[3])) or \
+           (len(entry) > 4 and entry[4] is not None and not callable(entry[4])) or \
+           (len(entry) > 5 and entry[5] is not None and not callable(entry[5])):
             raise CodecRegistryError,\
-                  'incompatible codecs in module "%s" (%s)' % \
-                  (mod.__name__, mod.__file__)
+                'incompatible codecs in module "%s" (%s)' % \
+                (mod.__name__, mod.__file__)
+        if len(entry)<7 or entry[6] is None:
+            entry += (None,)*(6-len(entry)) + (mod.__name__.split(".", 1)[1],)
+        entry = codecs.CodecInfo(*entry)
 
     # Cache the codec registry entry
     _cache[encoding] = entry