• 10 Posts
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Joined 4 years ago
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Cake day: May 31st, 2020

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  • For others wondering what’s wrong with UUIDv4:

    UUID versions that are not time ordered, such as UUIDv4, have poor database-index locality. This means that new values created in succession are not close to each other in the index; thus, they require inserts to be performed at random locations. The resulting negative performance effects on the common structures used for this (B-tree and its variants) can be dramatic.

    I guess, this means with these new UUIDs, ideally you only create UUIDs on systems that are hooked up to NTP, though I guess, it won’t really be worse than UUIDv4 either way.




  • We’ve been using Leptos at work, which is a similar framework (and probably shares half the stack with Dioxus).

    And yeah, it’s really good. My favorite thing about using Rust for the UI is algebraic data types.
    So, in Rust when you call a function which can fail, there isn’t an exception being thrown, but rather you get a Result-type as return value.
    This Result can either contain an Ok with the actual return value inside. Or it can contain an Err with an error message inside.
    So, in your UI code, you just hand this Result all the way to your display code and there you either display the value or you display the error.

    No more uninitialized variables, no more separate booleans to indicate that the variable is uninitialized, no more unreadable multi-line ternaries.
    It just becomes so much simpler to load something from the backend and display it, which is kind of important in frontend code.





  • I actually even made my own bullshit-Spotify. As in, I’ve got a server running on a single-board computer which reads my music folder and serves a small music player as a webpage.

    I didn’t want to install a music player client on my work laptop, but still wanted to listen to my own songs there.





  • But that is what I mean with it needing an extension of the language.

    So, I’m not saying you could just build a library that calls existing PHP functions to make it all work. Rather I’m saying there’s certain machine code instructions, which just cannot be expressed in PHP. And we need those machine code instructions for actually managing memory. So, I am talking about reading/writing to memory not being possible, unless we resort to horrible hacks.

    Since we are building our own compiler anyways, we could add our own function-stubs and tell our compiler to translate them to those missing machine code instructions. But then that is a superset of PHP. It wouldn’t be possible in PHP itself.

    Again, I’m not entirely sure about the above, but my web search skills couldn’t uncover any way to actually just read from a memory address in PHP.


  • I mean, I’m a bit out of my water there, both in terms of the featureset of PHP and what’s actually needed for a kernel, but I’m still gonna go with no.

    For one, PHP uses reference counting + garbage collection for memory management. That’s normally done by the language runtime, which you won’t have when running baremetal.

    Maybe you could implement a kernel, which does as few allocations as possible (generally a good idea for a kernel, but no idea, if it’s possible with PHP), and then basically just let it memory leak until everything crashes.
    Then again, the kernel is responsible for making processes crash when they have a memory leak. Presumably, our PHP kernel would just start overwriting data from running processes and eventually overwrite itself in memory(?). Either way, it would be horrendous.

    Maybe you could also try to implement some basic reference counting into your own PHP code, so that your own code keeps track of how often you’ve used an object in your own code. Certainly doesn’t sound like fun, though.

    Well, and secondly, I imagine, you’d also still need an extension of the language, to be able to address actual memory locations and do various operations with them.

    I know from Rust, that they’ve got specific functions in the stdlib for that, see for example: https://doc.rust-lang.org/stable/std/ptr/index.html#functions
    Presumably, PHP does not have such functions, because its users aren’t normally concerned with that.





  • I mean, presumably there’s a microcontroller in this radio. For programming that, your only real mainstream choices are C, C++ and Rust, since you can’t have a language runtime without a filesystem.

    But yeah, it’s neither the case that Rust is overwhelmingly popular for that (C/C++ do stick around still), nor is it the only discipline where Rust shines.