Functions

Function declarations

Three keywords mean the same thing — function, fn, and def:

function square(n) {
    return n * n
}
print(square(5))

The Java target wraps functions inside a Main class for you; other targets emit top-level functions (or func in Go).

Arguments passed positionally

function power(base, exp) {
    return base ** exp
}
print(power(2, 8))

def power(base, exp):
    return base ** exp

print(power(2, 8))

function power(base, exp) {
    return Math.pow(base, exp)
}
console.log(power(2, 8))

Typed parameters

If a parameter carries a type annotation, it is emitted typed:

function gcd(a int, b int) int {
    if b == 0 {
        return a
    }
    return gcd(b, a % b)
}
print(gcd(48, 18))

Typed functions are the reliable path to Go output that compiles, because untyped parameters produce invalid Go (n * n on interface{}). See Portability.

return

return works with and without a value. The Go emitter supplies return correctly even when a branch ends the function implicitly.

Lambdas

var double = (x) => x * 2
print(double(4))

Recursion and defaults

Recursion works (see gcd above). Default/optional parameters are not yet modeled — pass all arguments explicitly (Planned for default values).