These are patches to add lazy processing to Unicode strings for Python 3000.  I plan to post separate patches for both "lazy concatenation" and "lazy slices", as I suspect "lazy concatenation" has a much higher chance of being accepted.

There is a long discussion about "lazy concatenation" here:
http://mail.python.org/pipermail/python-dev/2006-October/069224.html
And another long discussion about "lazy slices" here:
http://mail.python.org/pipermail/python-dev/2006-October/069506.html

Note that, unlike the 8-bit-character strings patches, I don't expect the "lazy slices" patch to be dependent on the "lazy concatenation" patch.  Unicode objects are stored differently, and already use a pointer to a separately-allocated buffer.   This was the big (and mildly controversial) change made by the 8-bit-character "lazy concatenation" patch, and "lazy slices" needed it too.  Since Unicode objects already look like that, the Unicode lazy patches should be independent.