Programming Leftovers

posted by Roy Schestowitz on Dec 27, 2025

• Anton Zhiyanov ☛ 'Better C' playgrounds

  I believe playgrounds and interactive documentation make programming languages easier for more people to learn. That's why I created online sandboxes for these langs. You can try them out below, embed them on your own website, or self-host and customize them.

  If you're already familiar with one of these languages, maybe you could even create an interactive guide for it? I'm happy to help if you want to give it a try.

• Python

  • University of Toronto ☛ Python 2, GNU Emacs, and my LSP environment combine to shoot me in the foot

    The second thing I discovered is that in my environment this doesn't happen for Python 3 code. With my normal Python 3 GNU Emacs LSP environment, using python-lsp-server (pylsp) (also), the LSP environment will make no changes and report 'No formatting changes provided'. My problem only happens in Python 2 buffers, and that's because in Python 2 buffers I wasn't using pylsp (which only officially supports Python 3 code) but instead the older and now unsupported pyls. Either pyls has always behaved differently than pylsp when the LSP server asks it to do formatting stuff, or at some point the LSP protocol and expectations around formatting actions changed and pyls (which has been unmaintained since 2020) didn't change to keep up.

• Politics

  • Kerrick Long ☛ Useful Work Produced by People We Find Reprehensible - Kerrick Long (blog)

    Ruby got a new website for its 30th birthday. This upset a lot of folks, for one simple reason. I hope this quote from Austin Kleon helps you to Keep Going.

  • Simon Willison ☛ How uv got so fast

    I wanted to learn more about these tricks, so I fired up an asynchronous research task and told it to checkout the astral-sh/uv repo, find the Rust code for both of those features and try porting it to Python to help me understand how it works.

  • Andrew Nesbitt ☛ How uv got so fast

    uv installs packages faster than pip by an order of magnitude. The usual explanation is “it’s written in Rust.” That’s true, but it doesn’t explain much. Plenty of tools are written in Rust without being notably fast. The interesting question is what design decisions made the difference.

    Charlie Marsh’s Jane Street talk and a Xebia engineering deep-dive cover the technical details well. The interesting parts are the design decisions: standards that enable fast paths, things uv drops that pip supports, and optimizations that don’t require Rust at all.