diff options
| -rw-r--r-- | src/gleam/set.gleam | 15 | ||||
| -rw-r--r-- | test/gleam/set_test.gleam | 7 |
2 files changed, 22 insertions, 0 deletions
diff --git a/src/gleam/set.gleam b/src/gleam/set.gleam index 12bfba1..9e64b07 100644 --- a/src/gleam/set.gleam +++ b/src/gleam/set.gleam @@ -218,6 +218,21 @@ pub fn filter( Set(dict.filter(in: set.dict, keeping: fn(m, _) { predicate(m) })) } +/// Creates a new set from a given set with the result of applying the given +/// function to each member. +/// +/// ## Examples +/// +/// ```gleam +/// map(from_list([1, 2, 3, 4], fn(x) { x * 2 })) +/// // -> [2, 4, 6, 8] +/// ``` +pub fn map(set: Set(member), with fun: fn(member) -> mapped) -> Set(mapped) { + fold(over: set, from: new(), with: fn(acc, member) { + insert(acc, fun(member)) + }) +} + /// Creates a new set from a given set with all the same entries except any /// entry found on the given list. /// diff --git a/test/gleam/set_test.gleam b/test/gleam/set_test.gleam index 908fe29..46d4d13 100644 --- a/test/gleam/set_test.gleam +++ b/test/gleam/set_test.gleam @@ -83,6 +83,13 @@ pub fn fold_test() { |> should.equal(13) } +pub fn map_test() { + [1, 2, 3, 4] + |> set.from_list + |> set.map(with: fn(x) { x * 2 }) + |> should.equal(set.from_list([2, 4, 6, 8])) +} + pub fn filter_test() { [1, 4, 6, 3, 675, 44, 67] |> set.from_list() |