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Diffstat (limited to 'src/gleam/set.gleam')
| -rw-r--r-- | src/gleam/set.gleam | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/src/gleam/set.gleam b/src/gleam/set.gleam index a654200..09e92a5 100644 --- a/src/gleam/set.gleam +++ b/src/gleam/set.gleam @@ -1,5 +1,6 @@ import gleam/map.{Map} import gleam/result +import gleam/list /// A set is a collection of unique elements of the same type. /// @@ -65,6 +66,8 @@ pub fn contains(in set: Set(element), this member: element) -> Bool { /// Remove an element from a set. If the set does not contain the element then /// the set is returned unchanged. /// +/// This function runs in logarithmic time. +/// /// ## Examples /// /// > new() |> insert(2) |> delete(2) |> contains(1) @@ -79,6 +82,8 @@ pub fn delete(from set: Set(element), this member: element) -> Set(element) { /// The list has no specific ordering, any unintentional ordering may change in /// future versions of Gleam or Erlang. /// +/// This function runs in linear time. +/// /// ## Examples /// /// > new() |> insert(2) |> to_list @@ -87,3 +92,22 @@ pub fn delete(from set: Set(element), this member: element) -> Set(element) { pub fn to_list(set: Set(element)) -> List(element) { map.keys(set.map) } + +/// Create a new set of the elements in a given list. +/// +/// This function runs in loglinear time. +/// +/// ## Examples +/// +/// > import gleam/list +/// > [1, 1, 2, 4, 3, 2] |> from_list |> to_list |> list.sort +/// [1, 3, 3, 4] +/// +pub fn from_list(elements: List(element)) -> Set(element) { + let map = list.fold( + over: elements, + from: map.new(), + with: fn(k, m) { map.insert(m, k, []) }, + ) + Set(map) +} |