Classes and Interfaces

Nominal classes, new { ... } fields, methods, and interfaces.

interface Named {
    fn name(this) -> str;
}

class Point {
    new {
        x: int = 0;
        y: int = 0;
    }

    fn origin() -> Point {
        return Point {};
    }

    fn length(this) -> int {
        return this.x * this.x + this.y * this.y;
    }
}

class User implements Named {
    new {
        label: str;
    }

    fn name(this) -> str {
        return this.label;
    }
}

fn show(n: Named) {
    say(n.name());
}

p: Point = Point.origin();
say(Point.length(Point { x: 3, y: 4 }));
show(User { label: "Ada" });

25
Ada

Runnable copy: examples/classes_and_interfaces.echo.

Notes

• Fields live under new { ... }. Defaults let callers omit fields (Point {}).
• Instance methods take this; type methods omit it (Point.origin()).
• Unbound form: Point.length(p).
• implements is optional; inference still assigns matching classes to interfaces.
• No class inheritance — use interfaces and composition.

See Also

• Variables and Types
• Language Reference
• Known Limitations