iterator

Iterators produce values lazily.

Creating iterators

// Examples:
var s = "hello";
var it = iter s;

// Creates an iterator internally
for(var c : s) {
    // ...
}

Property	Description	Example
`.available`	Returns whether the iterator has more values to produce	`it.available` → true
`.next`	Returns the next value and advances the iterator	`it.next` → h

var l = [1, 2, 4];
var s = "hello";

var it1 = iter l;
var it2 = iter s;

it1 == it2;  // false
it1 == it1;  // true
it2 == it2;  // true