Programming Leftovers

posted by Roy Schestowitz on Jun 02, 2026

• Hugo Daniel ☛ S-expressions the wrong way

  S-expressions give us that natural syntax for expressing nested hierarchical trees, and once our program is written as trees, it becomes tempting to let those trees rewrite themselves, a path that leads naturally to macros making syntax expand into more syntax. Such is the Lisp deal.

  What if we went the other way around?

• Josh Lospinoso ☛ Same Function, Three Realities

  If you answer “the first integer argument,” you are already in one ABI and wrong in another. In this all-integer call, ecx carries a on Windows x64. It carries d on System V AMD64.

  The register is real. The value is real. The bug is the schema.

• Max Bernstein ☛ Checking assembly with Z3

  Short post today. New ZJIT contributor dak2 submitted a PR to fix an overflow bug in fixnum division in ZJIT. We did the division fine, but lied about the type of the result in the case of dividing FIXNUM_MIN by -1. You can see how this is special-cased in CRuby: [...]

• Raymond Camden ☛ Creating a Heavy Rain Alert with RainDrop and Val Town

  Given an API key passed in an Authorization header, this gets the current precipitation for my location: [...]

• Rlang ☛ Our goodpractice Package Has New Superpowers

  The goodpractice package has been recommended by rOpenSci since it was first started just over 10 years ago by Gábor Csárdi.
  

• Pekka Väänänen ☛ Should you normalize RGB values by 255 or 256?

  Let’s say you’re writing an image processing program. The program takes in an image, converts it to floating point, does some processing and finally saves the modified pixels to disk as 8-bit colors. The question today concerns how exactly the integer-to-float conversion should be done. There are two approaches which, written in Python and NumPy, look like this: [...]

• Perl / Raku

  • Rakulang ☛ Rakudo Weekly 2026.22 Some AST Fruit

    TPRC It is just over 20 days before the start of The Perl and Raku Conference 2026 in Greenville, SC, USA. The Perl and Raku Conference or TPRC (formerly known as YAPC::NA) is a high-quality, inexpensive technical conference with its roots in the Perl Mongers user groups.

• Python

  • Paolo Melchiorre ☛ My PyCon Italia 2026

    What follows is a chronological collection of the posts I shared during PyCon Italia 2026 in Bologna, Italy, capturing moments from the conference as they happened: talks, community gatherings, behind-the-scenes organizing work, conversations with friends, and many of the small details that make each edition unique.

• Shell/Bash/Zsh/Ksh

  • Zsh ☛ zsh 5.9.1 released

    zsh 5.9.1 has been released and made available for download at the following locations: [...]

• Java/Golang

  • Farid Zakaria ☛ Every byte matters

    I have spent a large portion of my career working in Java. In that time, you get used to huge classes. New functionality? Just add a new method and field to the class. The cost of each new field is rarely considered. Performance is often considered from a classic computer science perspective by considering asymptotic analysis of the algorithms and data structures in-use.

    Turns out that even within a growth scale for your algorithm, such a simple for-loop O(N), time can vary dramatically if we have a little deeper understanding of the underlying hardware.

  • Alex Edwards ☛ Go Experiments Explained– Alex Edwards

    Go often ships with experimental features as part of a release.

    These experimental features can take different forms: sometimes they're completely new packages in the standard library, sometimes they're changes to the compiler or runtime, or – very occasionally – they can be breaking changes to Go's behavior.

    Most of the time, the purpose of experimental features is to get real-world feedback from users before something graduates to general availability and becomes a permanent part of Go. If the feature causes regressions, or gets negative feedback from the community, it can be changed before it is finalized – or even abandoned entirely.