fun abs(n: Numeric) {
	if n < 0:
		return -n;
	return n;
}

fun min(x, y) {
    if x < y:
        return x;
    return y;
}

fun max(x, y) {
    if x > y:
        return x;
    return y;
}

Func  = type(abs);
NFunc = type(print);
Numeric = int | float;
Callable = Func | NFunc;
Collection = List | Map;

# Stringify a number between 0 and 9.
fun stringFromDigit(digit: int) {
	assert(digit >= 0 and digit <= 9);
	return string.chr(string.ord("0") + digit);
}

# Stringify an unsigned integer
fun stringFromInteger(n: int) {

	# This function returns the magnitude of the
	# argument and the power of 10 with the same
	# magnitude.
	fun getIntegerMagnitude(n: int) {
		assert(n >= 0);
		magn = 0;
		powr = 1;
		# Basically grow the power until it's
		# bigger than the input.
		while n >= powr * 10: {
			powr = 10 * powr;
			magn = 1 + magn;
		}
		return magn, powr;
	}

	negative = (n < 0);
	
	# Get the power of 10 with the
	# magnitude of the input.
	_, power = getIntegerMagnitude(n);

	temp = abs(n); # Temporary copy of the input
	text = ""; # The output we're about to compute

	while power >= 1: {
		# Pop the leftmost digit from [temp].
		digit = temp / power; # Get the leftmost digit
		temp  = temp % power; # Remove it

		# Add the digit to the output.
		text = string.cat(text, stringFromDigit(digit));

		# Prep for the next iteration.
		power = power / 10;
	}

	if negative:
		text = string.cat("-", text);
	return text;
}

fun floatFromInteger(n: int)
	return 1.0 * n;

fun integerFromDigit(char: String) {
    res = ord(char) - ord('0');
    if res < 0 or res > 9:
    	error("String isn't a digit");
    return res;
}

fun append(array: List, item)
	array[count(array)] = item;