On Sun, Oct 27, 2019, at 03:10, Andrew Barnert wrote: > On Oct 26, 2019, at 19:59, Random832 <random...@fastmail.com> wrote: > > > > A string representation considering of (say) a UTF-8 string, plus an > > auxiliary list of byte indices of, say, 256-codepoint-long chunks [along > > with perhaps a flag to say that the chunk is all-ASCII or not] would > > provide O(1) random access, though, of course, despite both being O(1), > > "single index access" vs "single index access then either another index > > access or up to 256 iterate-forward operations" aren't *really* the same > > speed. > > Yes, but that means constructing a string takes linear time, because > you have to construct that index. You can’t just take a > read/recv/mmap/result of a C library/whatever and use it as a string > without doing linear work on it first.
constructing a string already takes linear time because you have to copy it into memory managed by the python garbage collector. And you can track whether you'll need the index in one pass while copying, rather than, as currently, having to do one pass to pick a representation and another to actually perform the copying and conversion, so my suggestion may have a cache locality advantage over the other way. _______________________________________________ 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/UY5IIRWPSB37XRKDHLJYECIIFWPZS5SN/ Code of Conduct: http://python.org/psf/codeofconduct/
