for: (from, to, f) => {
	index: from;
	loop {
		if not(inf(index, to)) break true;
		f(index);
		index <- add(index, 1)
	}
};

array_new: () => {
	r: obj();
	r <- set(r, "len", 0);
	r
};

array_len: (self) => {
	get(self, "len")
};

array_get: (self, index) => {
	get(self, str(index))
};

array_push: (self, e) => {
	i: array_len(self);
	self <- set(self, str(i), e);

	len: add (i, 1);
	self <- set(self, "len", len);
	self
};

array_pop: (self) => {
	l: array_len(self);
	if eq(l, 0) return false;
	
	i: sub(l, 1);
	e: array_get(self, i);
	self <- set(self, str(i), false);
	
	r: obj();
	r <- set(r, "tail", e);
	r <- set(r, "rest", self);
	r
};

array_print: (self) => {
	l: array_len(self);
	r: "[";
	for(0, l, (i) => {
		r <- add(r, array_get(self, i));
		r <- add(r, ", ")
	});
	r <- add(r, "]");
	out(r)
};

main: () => {
	a: array_new();
	a <- array_push(a, 1);
	a <- array_push(a, 2);
	a <- array_push(a, 3);
	a <- array_push(a, 4);
	array_print(a)
};

main();