On 10/7/2011 10:06 AM, Nick Coghlan wrote:
On Fri, Oct 7, 2011 at 9:21 AM, "Martin v. Löwis"<martin@v.loewis.de> wrote:
if (!PyUnicode_READY(foo)) is not better, also because of
PyUnicode_IS_READY(foo).
I prefer PyUnicode_IS_READY(foo)< 0 over PyUnicode_IS_READY(foo) == -1.
Ok, so feel free to replace all == -1 tests with< 0 tests as well.
I'll point out that the test for -1 is also widespread in Python, e.g. when checking return values from PyObject_SetAttrString, BaseException_init, PyThread_create_key, PyObject_DelAttrString, etc.
FWIW, I don't mind whether it's "< 0" or "== -1", so long as there's a comparison there to kick my brain out of Python boolean logic mode.
Is there any speed difference (on common x86/64 processors and compilers)? I would expect that '< 0' should be optimized to just check the sign bit and 'if n < 0' to 'load n; jump-non-negative'. -- Terry Jan Reedy