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Cake day: July 1st, 2023

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  • I’m no rust expert, but:

    you can use into_iter() instead of iter() to get owned data (if you’re not going to use the original container again). With into_iter() you dont have to deref the values every time which is nice.

    Also it’s small potatoes, but calling input.lines().collect() allocates a vector (that isnt ever used again) when lines() returns an iterator that you can use directly. You can instead pass lines.next().unwrap() into your functions directly.

    Strings have a method called split_whitespace() (also a split_ascii_whitespace()) that returns an iterator over tokens separated by any amount of whitespace. You can then call .collect() with a String turbofish (i’d type it out but lemmy’s markdown is killing me) on that iterator. Iirc that ends up being faster because replacing characters with an empty character requires you to shift all the following characters backward each time.

    Overall really clean code though. One of my favorite parts of using rust (and pain points of going back to other languages) is the crazy amount of helper functions for common operations on basic types.

    Edit: oh yeah, also strings have a .parse() method to converts it to a number e.g. data.parse() where the parse takes a turbo fish of the numeric type. As always, turbofishes arent required if rust already knows the type of the variable it’s being assigned to.








  • I’m not sure I understand your point about fall through having to be explicit

    As far as i understand it, every switch statement requires a break otherwise it’s a compiler error - which makes sense from the “fallthrough is a footgun” C perspective. But fallthrough isnt the implicit behavior in C# like it is in C - the absence of a break wouldnt fall through, even if it wasnt a compiler error. Fallthrough only happens when you explicitly use goto.

    But break is what you want 99% of the time, and fallthrough is explicit. So why does break also need to be explicit? Why isnt it just the default behavior when there’s nothing at the end of the case?

    It’s like saying “my hammer that’s on fire isnt safe, so you’re required to wear oven mitts when hammering” instead of just… producing a hammer that’s not on fire.

    From what i saw on the internet, the justification (from MS) was literally “c programmers will be confused if they dont have to put breaks at the end”.


  • the ergonomics expected of modern languages.

    As someone learning c# right now, can we get some of those “modern ergonomics” for switch statements 💀

    I cant believe it works the way it does. “Fallthrough logic is a dumb footgun, so those have to be explicit rather than the default. But C programmers might get confused somehow, so break has to be explicit too”

    I miss fallthrough logic in languages that dont have it, and the “goto case” feature is really sick but like… Cmon, there’s clearly a correct way here and it isnt “there is no default behavior”




  • I feel like it’s like pointers.

    “Variable” refers to the label, i.e. a box that can contain anything (like *ptr is a pointer to [something we dont know anything about])

    Immutable describes the contents, i.e. the stuff in the box cant change. (like int* ptr describes that the pointer points to an int)

    Rust makes it very obvious that there’s a difference between constants and immutable variables, mainly because constants must be compile time constants.

    What do you call it when a variable cant change after its definition, but isnt guaranteed to be the same on each function call? (E.g. x is an array that’s passed in, and we’re just checking if element y exists)

    It’s not a constant, the contents of that label are “changing”, but the label’s contents cant be modified inside the scope of that function. So it’s a variable, but immutable.





  • 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?





  • You could say that about anything. Of course you have to learn something the first time and it’s “unintuitive” then. Intuition is literally an expectation based on prior experience.

    Intuitive patterns exist in programming languages. For example, most conditionals are denoted with “if”, “else”, and “while”. You would find it intuitive if a new programming language adhered to that. You’d find it unintuitive if the conditionals were denoted with “dnwwkcoeo”, “wowpekg cneo”, and “coebemal”.