Functions: Gallium’s Workhorse

Functions can be created, called, and passed around. Gallium has first-class function support.

fn add(x: i32, y: i32) -> i32 {
    x + y
}

fn add_mul(x: i32, y: i32, z: i32) -> i32 {
    add(x, y) * z
} 

Function Pointers

Function pointers exist, and are implicitly created when referring to a function by name (without calling it).

let f = add

Higher-Order Functions

Functions can be passed around and used to create higher-order functions.

fn lazily_add(x: i32, f: fn() -> i32) -> i32 {
    x + f()
}

fn get_16() -> i32 {
    16
}

fn add_16(x: i32) -> i32 {
    lazily_add(x, get_16)
}