Functions

Functions in Nubo can be declared by name or created inline as values.

Named Functions

Use the fn keyword to declare a function:

fn add(a: int, b: int) int {
    return a + b
}

println(add(2, 3))

Void Functions

Use void when a function does not return a value:

fn say(message: string) void {
    println(message)
}

say("Hello")

Anonymous Functions

Anonymous functions can be assigned to variables or passed as arguments:

let add = fn(a: int, b: int) int {
    return a + b
}

println(add(1, 2))

They are especially useful for callbacks:

let total: int = 0

bytes("hello").map(int).each(fn(n: int) {
    total = total + n
})

println(total)

Returning Values

Use return to return a value from a function:

type hasLen: iface {
    length() int
}

fn length(obj: hasLen) int {
    return obj.length()
}

Function Parameters

Parameters are written with a name and type:

fn greet(name: string) void {
    println("Hello", name)
}

Interface Parameters

A function can accept any value matching an inline interface:

type hasLen: iface {
    length() int
}

fn len(obj: hasLen) int {
    return obj.length()
}

const name: string = "John"
println(len(name))