Generics

We use fixed types in our programs, but sometimes we want to write code that can operate on different types without duplicating it. Generics allow you to write flexible, reusable code that works with multiple types.

Generic Functions

To define a generic function, we use angle brackets <T> to specify type parameters.

fn identity<T>(value: T) -> T {
    return value;
}

let num := identity(42);         // T = i32
let text := identity("hello");   // T = str

Generic Structs

type Box<T> struct {
    .value: T,
};

let int_box := Box<i32>{.value: 42};
let str_box := Box<str>{.value: "hello"};

Generic Interfaces

type Container<T> interface {
    get() -> T;
    set(value: T);
};

Multiple Type Parameters

type Pair<K, V> struct {
    .key: K,
    .value: V,
};

let entry := Pair<str, i32>{.key: "age", .value: 30};

Generic Methods

type Box<T> struct {
    .value: T,
};

fn (b: Box<T>) get() -> T {
    return b.value;
}