Set

Sets are ordered, mutable collections with unique membership semantics.

Iteration preserves insertion order. Reinserting an existing value is a no-op and does not move it to the end.

Constructor

`Set iterable`

Builds a set from one iterable.

Fields

`len`

Returns the number of members.

Type

Int

Methods

`add value`

Adds value if it is not already present.

Parameters

Name	Type	Description
`value`		the value to insert

let s = Set [1, 2]
s.add 3
s.add 2
assert_eq [...s] [1, 2, 3]

`delete value`

Removes value if present.

Parameters

Name	Type	Description
`value`		the value to remove

Returns

Bool indicating whether a value was removed

`clear`

Removes all members.

let s = Set [1, 2]
s.clear()
assert_eq $s.len 0

`copy`

Returns a shallow copy of the Set.

Insertion order is preserved. Contained values are not recursively copied.

Returns

Set

`contains value`

Tests whether the Set contains value.

Parameters

Name	Type	Description
`value`		the value to test

Returns

Bool

`union other`

Returns a new Set containing all members from self, then first-seen members from other.

Parameters

Name	Type	Description
`other`	`Set`	other Set

Returns

Set

`intersect other`

Returns a new Set containing members that are present in both sets, in the receiver's insertion order.

Parameters

Name	Type	Description
`other`	`Set`	other Set

Returns

Set

`diff other`

Returns a new Set containing members from the receiver that are not present in other.

Parameters

Name	Type	Description
`other`	`Set`	other Set

Returns

Set

`sym_diff other`

Returns a new Set containing members present in exactly one of the two sets.

Parameters

Name	Type	Description
`other`	`Set`	other Set

Returns

Set

`is_subset other`

Returns true when every member of the receiver is present in other.

Parameters

Name	Type	Description
`other`	`Set`	other Set

Returns

Bool

`is_superset other`

Returns true when every member of other is present in the receiver.

Parameters

Name	Type	Description
`other`	`Set`	other Set

Returns

Bool

Operations

Iteration

Iterating a Set yields values in insertion order:

let s = Set [3, 1, 2, 1]
assert_eq [...s] [3, 1, 2]