Set

A set represents a collection, which is structurally a duplicate, unordered array.

assert Set.from([1, 2, 3, 2, 1]) == {1, 2, 3}
assert {1, 2} == {1, 1, 2} # duplicates are automatically removed
assert {1, 2} == {2, 1}

Sets can perform set operations.

assert 1 in {1, 2, 3}
assert not 1 in {}
assert {1} or {2} == {1, 2}
assert {1, 2} and {2, 3} == {2}
assert {1, 2} not {2} == {1}

A set is a homogeneous collection. In order for objects of different classes to coexist, they must be homogenized.

s: {Int or Str} = {"a", 1, "b", -1}

Sets as types

Sets can also be treated as types. Such types are called Enum types.

i: {1, 2, 3} = 1
assert i in {1, 2, 3}

Elements of the set are directly elements of the type. Note that the sets themselves are different.

mut_set = {1, 2, 3}.into {Int; !3}
mut_set.insert!(4)