// Method-style builtins on arrays, strings, dicts, and numbers

var a = [1, 2];
assert(a.len() == 2, "array.len()");
a.push(3, 4);
assert(a.len() == 4, "array.push(...)");
assert(a.pop() == 4, "array.pop() value");
assert(a.len() == 3, "array.pop() length");
assert(a[2] == 3, "array after push/pop");

var s = "hello";
assert(s.len() == 5, "string.len()");

var d = {"x": 1, "y": 2};
assert(d.len() == 2, "dict.len()");
var ks = d.keys();
var vs = d.values();
assert(ks.len() == 2, "dict.keys().len()");
assert(vs.len() == 2, "dict.values().len()");
assert(d.has("x"), "dict.has(true)");
assert(!d.has("z"), "dict.has(false)");

var n = 3.9;
assert(n.toInt() == 3, "number.toInt()");