setjs implements a a Set API inspired by Python. There are some differences, though. The biggest difference is that the API is immutable by design. There is a basic set structure and functions that operate upon it. Consider the API below:
var a = set(4, 3, 4, 3); // set accepts arbitrary amount of items and may be empty
var b = set(4, 5);
set.count(a); // 2
set.contains(a, 3); // true
set.equals(a, a); // true
set.equals(a, set()); // false
set.union(a, b); // {3, 4, 5}
set.intersection(a, b); // {4}
set.difference(a, b); // {5}
set.symmetricDifference(a, b); // {3, 5}The functions above may be used to perform various manipulations on sets.
MIT.