Interfaces

An interface is a type that defines a contract for the properties and methods that an object must implement. Interfaces are used to define the structure of an object without providing an implementation. This allows for the creation of objects that can be used interchangeably, as long as they implement the required properties and methods.

See also Classes.

Syntax

interface IDENTIFIER {
    [ FIELD_DECLARATION ]
    [ METHOD_DECLARATION ]
}

Field Declaration

IDENTIFIER: TYPE;

Method Declaration

IDENTIFIER(PARAMETER_LIST): RETURN_TYPE;

Examples

Simple interface definition

interface Person {
    name: str;
    age: num;
    sayHello(): void;
}

Assigning an object to an interface

interface Person {
    name: str;
    age: num;
    sayHello(): void;
}
var person: Person = {
    name: "Alice",
    age: 25,
    sayHello: (): void -> {
            print("Hello");
    }
};

person.sayHello(); // -> "Hello"

Matching an interface

See matches expression.

interface Person {
    name: str;
    age: num;
    sayHello(): void;
}

var person: obj = {
    name: "Alice",
    age: 25,
    sayHello: (): void -> {
        print("Hello");
    }
};

if (person matches Person) {
    print("Person matches interface");
}