Functions

A function call expression looks in cellox the same as it does in C.

foo(1);

Function definitions in cellox use the fun keyword and can return different types by the same function. A practical example would be a function that returns a number, or a boolean.

fun foo(number)
{
    if(a >= 0) 
        return false;
    return number ** 0.5; // Returns the square root of the number
}

Function declarations are statements, which gives you the ability to declare a local function inside another function.

fun fibonacci()
{
	var x = 0;
	var temp = 0;
	var b = 1;
	fun number()
	{
	     temp = x;
	     x = b;
	     b = temp + x;
	     return temp;
	}
	return number;
}

var fibo = fibonacci();
for (var j = 0; j < 10; j += 1) 
    printf("{}\n", fibo());