10 comments

  • Waterluvian 41 days ago
    Any sense how, if at all, C++ Immer and JS Immer relate as projects? They’re basically meant to be the same thing but I haven’t found either acknowledging the other.
    • acemarke 41 days ago
      Completely unrelated.

      - Immer (C++) appears to be roughly equivalent to Immutable.js ( https://immutable-js.com/ ): a set of specialized data structures

      - Immer (JS), on the other hand, uses JS Proxies to wrap plain values, traps attempted mutations, and then replays them to return a safely immutable updated final result

      As far as I know, Michel Weststrate came up with the name independently (although I can't 100% confirm that).

      (source: I didn't create Immer (JS), but I started using it in Redux Toolkit in 2018, am quoted in the docs about how much I love it, spent the last couple months doing performance optimization work that got shipped in Immer 11.x, and just put up some more bugfix PRs today. I'm a secondary maintainer at this point.)

      • benoits 41 days ago
        Thanks for your work, really appreciated the RTK perf boost!
    • eru 41 days ago
      'Immer' is just German for 'always' or 'eternal'. So giving that name to your library of persistent and immutable data structures is a fairly natural thing to do, without them having anything more in common than that.

      (Of course, they might have more in common, I don't know.)

      • MeteorMarc 41 days ago
        Immer is also a dutch word, with the same meaning as in german.
      • Hendrikto 40 days ago
        I would never translate “eternal” to “immer”, but rather “ewig”. “Always” is the corrent translation, imo.
        • eru 40 days ago
          Sure, though 'never' is a bit of a strong statement. It depends on context and what's idiomatic.

          An example:

          DE: Er schwor, ihr auf immer treu zu sein.

          EN: He swore to be eternally faithful to her.

          • Hendrikto 36 days ago
            True, that works, but I still think “Er schwor, ihr ewig treu zu sein.” is the more natural translation.
  • gnabgib 47 days ago
    Popular in:

    2019 (102 points, 56 comments) https://news.ycombinator.com/item?id=20947222

    2016 (144 points, 46 comments) https://news.ycombinator.com/item?id=13049843

  • naruhodo 41 days ago
    For the curious, yes they provide a garbage-collected heap [1] as well as reference counting.

    [1] https://sinusoid.es/immer/memory.html#classimmer_1_1gc__heap

  • bjoli 40 days ago
    Cool! I just implemented RBB trees for c#. Not on this level, mostly just for fun. I am not a programmer at all, but I do like myself a neat data structure.

    I am currently fighting the JIT to understand why a simple flags check (ANDing two bytes and comparing to 0) makes the code 2.5x slower. This is my first c# project so right now I am just throwing things at the compilrr to see what sticks. If anyone knows where I can get help, that would be much appreciated. Dont look too closely on the benchmarks. I managed to make two of them an absolutely best case for ImmutableList (especially SetItem which should degrage linearly with size but now is O(1))

    https://github.com/bjoli/RrbList/tree/main/src/Collections

    Another thing I havent figured out is how to setup docfx to just pull my XML comments and generate API documentation.

  • gignico 41 days ago
    I used this library extensively in a prototype of a project and it was awesome!

    Besides performance, the API is very well thought.

  • actionfromafar 40 days ago
    This library always makes me feel small - as in, I wish I did the cool things which call for such solutions. :)
  • dacapoday 39 days ago
    I just tried building some immutable data structures in Go: (https://github.com/dacapoday/smol) a kv store base on cow b+ tree
    • dacapoday 39 days ago
      In-memory immuatable data structures seem to be only suitable for scenarios with large amounts of data and high concurrency. In most scenarios, this actually incurs a lot of additional copying overhead.
  • nurettin 41 days ago
    Anyone else religiously went through 490 packages in cppget to make sure they aren't missing out?
  • asa 41 days ago
    Good stuff. Very good stuff.
  • alexpadula 40 days ago
    Really cool!