Function Type - Func<ARGS..., RET>

The function type is a special type that represents a function. It is used to define functions and to call functions by storing them in variables.

Generic Arguments

ARGS...

An exhaustive list of arguments that the function takes. This may be empty if the function does not take any arguments.

This list takes in each element except the last one.

RET

The return type of the function. This may be void if the function does not return anything.

Examples

Assigning named function and calling it from the reference variable

def add(a: num, b: num) -> num {
        return a + b;
}

var add_func: Func<num, num, num> = add;
var result: num = add_func(2, 3);
print(result); // -> 5

Assigning anonymous lambda function and calling it from the reference variable

var add_func: Func<num, num, num> = (a: num, b: num): num -> {
        return a + b;
};

var result: num = add_func(2, 3);
print(result); // -> 5

Assigning anonymous lambda function with no arguments and calling it from the reference variable

var hello_func: Func<void> = (): void -> {
        print("Hello, World!");
};

hello_func(); // -> "Hello, World!"

Passing on a function as a function argument

def forEach(values: Array<num>, func: Func<num, void>) -> void {
    for (var i: num = 0; i < len(values); i++) {
        func(values[i]);
    }
}

var f: Func<num, void> = (arg: num): void -> {
    print(arg ** arg);
};
forEach([1, 2, 3, 4, 5, 6, 7, 8, 9], f);
// ->
// 1
// 4
// 27
// 256
// 3125
// 46656
// 823543
// 16777216
// 387420489