[Python-3000] Making more effective use of slice objects in Py3k (original) (raw)

Bob Ippolito bob at redivi.com
Thu Aug 31 05:56:03 CEST 2006

On 8/30/06, Fredrik Lundh <fredrik at pythonware.com> wrote:

Fredrik Lundh wrote:

> not necessarily, but there are lots of issues involved when doing > high-performance XML stuff, and I'm not sure views would help quite as > much as one might think. > > (writing and tuning cET was a great way to learn that not everything > that you think you know about C performance applies to C code running > inside the Python interpreter...) and also based on the cET (and NFS) experiences, it wouldn't surprise me if a naive 32-bit text string implementation will, on average, slow things down more than any string view implementation can speed things up again... (in other words, I'm convinced that we need a polymorphic string type. I'm not so sure we need views, but if we have the former, we can use that mechanism to support the latter)

+1 for polymorphic strings.

This would give us the best of both worlds: compact representations for ASCII and Latin-1, full 32-bit text when needed, and the possibility to implement further optimizations when necessary. It could add a bit of complexity and/or a massive speed penalty (depending on how naive the implementation is) around character operations though.

For implementation ideas, Apple's CoreFoundation has a mature implementation of polymorphic strings in C (which is the basis for their NSString type in Objective-C), and there's a cross-platform subset of it available as CF-Lite: http://developer.apple.com/opensource/cflite.html

-bob

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