code that's been written today has been made obsolete by a language feature in the latest nightly build
I mean couldnt you say that about any language? There's lots of old C code that's obsoleted by features in C11. There's lots of stuff written in python today that's obsoleted by stuff in the 3.13 alpha. It's just kinda how things go.
Doesnt the edition system prevent this from being too big of an issue anyway?
Here's the script. It's nothing fancy, and iirc it only works for top level functions/classes. That means you still have to take care of attributes and methods which is a little annoying, but for simple stuff it should save a bit of time.
For downsides, i'd like to add that the lack of function overloading and default parameters can be really obnoxious and lead to [stupid ugly garbage].
A funny one i found in the standard library is in time::Duration. Duration::as_nanos() returns a u128, Duration::from_nanos() only accepts a u64. That means you need to explicitly downcast and possibly lose data to make a Duration after any transformations you did.
They cant change from_nanos() to accept u128 instead because that's breaking since type casting upwards has to be explicit too (for some reason). The only solution then is to make a from_nanos_u128() which is both ugly, and leaves the 64 bit variant hanging there like a vestigial limb.
Pyo3 doesnt generate type hints at all iirc. There's some more info here
The gist, as i recall, is that you're supposed to maintain a .pyi file in the rust project folder that gets automatically added in by maturin when building. I'm no regex wizard, but i was able to whip together a small script that generates simple function and class stubs that also have the rust docstring. Iirc they're planning on adding some official support for generating type hints, but i have no idea how far along it is or where it is on the priority list
It's most useful when you're using some data you already have as the dictionary key. A usecase i had for this was a binary file parser with 10 types of event markers. It was originally coded with if/elif, but performance was a pretty big consideration. Using the event markers as keys to a dictionary dispatch improved performance by about 15% and made the code significantly more readable.
in this case it's about 80% function calls. They're convenience functions for assembly instructions, so they're of the form:
load(Reg::D, "A"),
load_const(5),
which is more useful than variables would be. I guess i could use .join or a crate like concat_string? Either way i sorely miss arbitrary expression format strings from python =(
Honestly, it's because a bunch of programs i used disappointed me (performance, functionality, [being a web app at all], etc.) and i figured it couldnt be that hard to do it better. In some cases i was right, in most i was wrong. As it turns out though, I really like programming so i guess i'm stuck here