• lysdexic@programming.dev
    link
    fedilink
    English
    arrow-up
    1
    ·
    edit-2
    1 year ago

    (…) what, pray tell, is the point of protocols, other than backward compatibility with historical fragile ducks (at the cost of future backwards compatibility)?

    Got both of those wrong. The point of protocols is to have a way to validate duck typing errors by adding a single definition of a duck. This is not something that only applies to backwards compatible, nor does it affects backwards compatibility.

    Why are people afraid of using real base classes?

    You’re missing the whole point of prototypes. The point of a prototype is that you want duck typing, not inheritance. Those are entirely different things, and with prototypes you only need to specify a single prototype and use it in a function definition, and it automatically validates each and any object passed to it without having to touch it’s definition or add a base class.

    • o11c@programming.dev
      link
      fedilink
      arrow-up
      1
      ·
      1 year ago

      That still doesn’t explain why duck typing is ever a thing beyond “I’m too lazy to write extends BaseClass”. There’s simply no reason to want it.

      • lysdexic@programming.dev
        link
        fedilink
        English
        arrow-up
        1
        ·
        1 year ago

        I already explained it to you: protocols apply to types you do not own or control, let alone can specify a base class.

        You just specify a protocol, specify that a function requires it, and afterwards you can pass anything to it as-is and you’ll be able to validate your calls.

          • lysdexic@programming.dev
            link
            fedilink
            English
            arrow-up
            1
            ·
            edit-2
            1 year ago

            I’m not sure you understand that what a union does or does not do is completely irrelevant and besides the point. Python’s protocols add support for structural subtyping, and enable both runtime and build-time type checks without requiring major code changes. Don’t you understand what that means?