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.
diff --git a/Lib/encodings/utf_16.py b/Lib/encodings/utf_16.py
index 95abb05..eff08f3 100644
--- a/Lib/encodings/utf_16.py
+++ b/Lib/encodings/utf_16.py
@@ -15,6 +15,47 @@
def decode(input, errors='strict'):
return codecs.utf_16_decode(input, errors, True)
+class IncrementalEncoder(codecs.IncrementalEncoder):
+ def __init__(self, errors='strict'):
+ codecs.IncrementalEncoder.__init__(self, errors)
+ self.encoder = None
+
+ def encode(self, input, final=False):
+ if self.encoder is None:
+ result = codecs.utf_16_encode(input, self.errors)[0]
+ if sys.byteorder == 'little':
+ self.encoder = codecs.utf_16_le_encode
+ else:
+ self.encoder = codecs.utf_16_be_encode
+ return result
+ return self.encoder(input, self.errors)[0]
+
+ def reset(self):
+ codecs.IncrementalEncoder.reset(self)
+ self.encoder = None
+
+class IncrementalDecoder(codecs.BufferedIncrementalDecoder):
+ def __init__(self, errors='strict'):
+ codecs.BufferedIncrementalDecoder.__init__(self, errors)
+ self.decoder = None
+
+ def _buffer_decode(self, input, errors, final):
+ if self.decoder is None:
+ (output, consumed, byteorder) = \
+ codecs.utf_16_ex_decode(input, errors, 0, final)
+ if byteorder == -1:
+ self.decoder = codecs.utf_16_le_decode
+ elif byteorder == 1:
+ self.decoder = codecs.utf_16_be_decode
+ elif consumed >= 2:
+ raise UnicodeError("UTF-16 stream does not start with BOM")
+ return (output, consumed)
+ return self.decoder(input, self.errors, final)
+
+ def reset(self):
+ codecs.BufferedIncrementalDecoder.reset(self)
+ self.decoder = None
+
class StreamWriter(codecs.StreamWriter):
def __init__(self, stream, errors='strict'):
self.bom_written = False
@@ -52,5 +93,12 @@
### encodings module API
def getregentry():
-
- return (encode,decode,StreamReader,StreamWriter)
+ return codecs.CodecInfo(
+ name='utf-16',
+ encode=encode,
+ decode=decode,
+ incrementalencoder=IncrementalEncoder,
+ incrementaldecoder=IncrementalDecoder,
+ streamreader=StreamReader,
+ streamwriter=StreamWriter,
+ )