[Python-3000] int-long unification (original) (raw)

Guido van Rossum guido at python.org
Sun Aug 20 18:43:05 CEST 2006

On 8/20/06, "Martin v. Löwis" <martin at v.loewis.de> wrote:

Guido van Rossum schrieb: > Are you interested in doing this at the Google sprint next week?

Sure; I hadn't any special plans so far. > What do you think? Sounds good. There are two problems I see: - how to benchmark?

We could possibly do a lot of int allocations and deallocations in a temporary extension module.

- there are subtle details in the API that require changes to extension code. In particular, PyIntAsLong currently cannot fail, but can fail with a range error after the unification.

However, to evaluate the performance, it is possible to work around that. For this specific problem, I would propose to introduce another API, say int PyLongToLong(PyObject* val, long* result); which will return true(1) for success, and set an exception in case of a failure. Then, we get long PyLongAsLong(PyObj *val) { long result; if(!PyLongToLong(val, &result))return -1; return result; } and perhaps long PyIntAsLong(PyObj* val) { long result; if(!PyLongToLong(val, &result)) PyFatalError("old-style integer conversion failed"); return result; }

The fatal error strikes me as unpleasant. Perhaps PyInt_Check[Exact] should return false if the value won't fit in a C long? Or perhaps we could just return -sys.maxint-1?

-- --Guido van Rossum (home page: http://www.python.org/~guido/)

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