I probably should have added "user exposed" or something to my comment.
Those extra bits certainly seem to offer compiler optimization
possibilities, as apparently SpiderMonkey does with WASM.
I can easily *imagine* a library like NumPy or PyTorch deciding to expose
something useful with those 52 unused mantissa bits. But that's some future
version, if ever.
On Sat, Sep 12, 2020, 2:16 PM Cade Brown
As per tagged nans, check for JavaScript tagged NaN optimization. Essentially, the tag of the NaN (i.e. the mantissa) is interpreted as a pointer. Obviously, this is a very advanced use case, probably not worth Python guaranteeing such behavior. Here is one article: https://brionv.com/log/2018/05/17/javascript-engine-internals-nan-boxing/
On Sat, Sep 12, 2020, 8:10 PM David Mertz
wrote: On Sat, Sep 12, 2020, 2:02 PM Steven D'Aprano
wrote: In general though, Python doesn't support generating the full range of NANs with payloads directly.
I've researched this a little bit for discussion in a book I'm writing, and I have not been able to identify ANY widely used programming language or tool that does anything meaningful with the NaN payloads.
It's possible I've missed something, but certainly not the top 20 languages are libraries that might come to mind. _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-leave@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/FZ7QGR... Code of Conduct: http://python.org/psf/codeofconduct/