[Python-Dev] PEP 3118: Extended buffer protocol (new version) (original) (raw)

Greg Ewing greg.ewing at canterbury.ac.nz
Sat Apr 14 03:41:11 CEST 2007

Travis Oliphant wrote:

PyBUFSIMPLE --- you are requesting the simplest possible (0x00)

PyBUFWRITEABLE -- get a writeable buffer (0x01) PyBUFREADONLY -- get a read-only buffer (0x02)

I don't see how these three form a progression.

From the other things you say, it appears you mean Py_BUF_SIMPLE to mean both readable and writeable. But then Py_BUF_READONLY is turning off a capability (being able to write to the buffer) rather than turning one on.

Seems to me the "simplest possible" buffer is a read-only one (assuming we don't want to allow for write-only buffers -- or do we?), in which case a more logical arrangement to my mind would be

Py_BUF_READONLY = 0x00 # simplest possible PY_BUF_READWRITE = 0x01

If we do want write-only buffers, then there isn't a single simplest possible buffer, except for one that's neither readable nor writable, which doesn't seem very useful. So we would have

Py_BUF_READABLE = 0x01 Py_BUF_WRITABLE = 0x02 Py_BUF_READWRITE = 0x03

-- Greg

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