On Thu, Dec 9, 2021 at 11:47 AM David Mertz, Ph.D. <david.me...@gmail.com> wrote: > > There are tens of concrete examples at the link I gave, and hundreds more you > can find easily by searching on Dask Delayed. This feels more like trying to > believe a contrary than seeking understanding. > > Here's a concrete example that I wrote last summer. I wanted to write a > similar program in a bunch of programming languages to learn those languages. > From long ago, I had a Python implementation (which I improved quite a lot > through the exercise, as well). > > https://github.com/DavidMertz/LanguagePractice > > What the programs do is identify any duplicate files in a filesystem tree > (i.e. perhaps among millions of files, often with different names but same > content). > > The basic idea is that a hash like SHA1 serves as a fingerprint of contents. > However, the main speedup potential is in NOT computing the hash when files > are either hardlinks or soft links to the same underlying inode. I/O nowadays > is more of a hit than CPU cycles, but the concept applies either way. > > Essentially the same technique is used in all the languages. But in the > Haskell case, it is NECESSARY to express this as deferred computation. I > don't want Python to be like Haskell, which was in most ways the most > difficult to work with. > > However, it would be interesting and expressive to write a Python version > based around Dask Delayed... Or around a generalized "deferred" construct in > Python 3.13, maybe. I'm pretty sure it could be shorter and more readable > thereby. >
The basic and obvious way to write that is a simple dictionary lookup. It's not particularly hard to recognize inode numbers without a deferred/delayed construct. And this is still arguing for their benefit in the wider language, with no indication of how it's better for default arguments. This is a MASSIVE amount of overhead for simple cases of "x=>[]" or similar. ChrisA _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@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/KIUHKKIERJG2U5VDWVKT3YQMVHBVQLSA/ Code of Conduct: http://python.org/psf/codeofconduct/
