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Comment by vips7L

4 months ago

What language are you using that doesn’t have match? Even Java has the equivalent. The only ones I can think of that don’t are the scripting languages.. Python and JS.

12 comments

vips7L

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tonyedgecombe  4 months ago

Does Java have sum types now?

  • vips7L  4 months ago

    Yes via sealed classes. It also has pattern matching.

    • cies  3 months ago

      So they are there, but ugly to define:

          public abstract sealed class Vehicle permits Car, Truck {
      public Vehicle() {}
    }

    public final class Truck extends Vehicle implements Service {
      public final int loadCapacity;

      public Truck(int loadCapacity) {
        this.loadCapacity = loadCapacity;
      }
    }

    public non-sealed class Car extends Vehicle implements Service {
      public final int numberOfSeats;
      public final String brandName;

      public Car(int numberOfSeats, String brandName) {
        this.numberOfSeats = numberOfSeats;
        this.brandName = brandName;
      }
    }

      In Kotlin it's a bit better, but nothing beats the ML-like langs (and Rust/ReScript/etc):

          type Truck = { loadCapacity: int }
    type Car = { numberOfSeats: int, brandName: string }
    type Vehicle = Truck | Car

      4 replies →

pjmlp  3 months ago

Python has it as well.

  • vips7L  3 months ago

    Ah my mistake. It’s been at least 5 years since I’ve written it. I’m honestly surprised that JS has moved no where on it considering all of the fancy things they’ve been adding.