• esa@discuss.tchncs.de
    6·
    4 hours ago

    I’m used to named arguments from other languages, and that makes me fairly partial to them. Having to tool around with builders feels a lot more complex and clunky.

    That said, I do wonder at how many of the usecases aren’t workarounds for long argument lists that are either stringly typed, or something similar. As in, with a signature of (i32,i32,i32,i32) -> whatever, named arguments seem like a way of getting the compiler to catch errors in confusing {x,y}_{position,length}; but if the signature were newtypes like Rect(Origin(i32,i32), Size(i32, i32)) -> whatever, then the felt need for named arguments drops considerably.

    • anton@lemmy.blahaj.zone
      5·
      2 hours ago

      With newtypes you can also emulate named args with a single struct. This also allows them to be passed on together.

      struct RectArgs{
    x:i32,
    y:32,
    w:32,
    h:32,
}
impl Default for RectArgs{...}

      Then the call site looks like this:

      rect(RectArgs{
    x:0,
    y:0,
    w:30,
    h:20,
}
// with default arguments
rect(RectArgs{
    w:30,
    h:20,
    .. RectArgs::default ()
}
      • esa@discuss.tchncs.de
        1·
        1 hour ago

        Yeah, though in those cases you might get an extra question about why rect is a function and not a method, e.g.

        Rect {
     w: 30,
     h: 20,
     .. RectArgs::default()
}.do_the_thing()