diff options
| -rw-r--r-- | src/gleam/list.gleam | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/src/gleam/list.gleam b/src/gleam/list.gleam index 0622147..869fc10 100644 --- a/src/gleam/list.gleam +++ b/src/gleam/list.gleam @@ -1480,6 +1480,16 @@ pub fn combinations(items: List(a), by n: Int) -> List(List(a)) { } } +fn do_combinations_by_2(items: List(a)) -> List(List(tuple(a, a))) { + case items { + [] -> [] + [x, ..xs] -> { + let first_combinations = map(xs, with: fn(other) { tuple(x, other) }) + [first_combinations, combinations_by_2(xs)] + } + } +} + /// Return unique pair combinations of elements in the list /// /// ## Examples @@ -1490,11 +1500,6 @@ pub fn combinations(items: List(a), by n: Int) -> List(List(a)) { /// ``` /// pub fn combinations_by_2(items: List(a)) -> List(tuple(a, a)) { - case items { - [] -> [] - [x, ..xs] -> { - let first_combinations = map(xs, with: fn(other) { tuple(x, other) }) - append(first_combinations, combinations_by_2(xs)) - } - } + do_combinations_by_2(items) + |> flatten } |