diff options
| -rw-r--r-- | src/gleam/list.gleam | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/src/gleam/list.gleam b/src/gleam/list.gleam index 662e3f7..570769d 100644 --- a/src/gleam/list.gleam +++ b/src/gleam/list.gleam @@ -1220,9 +1220,6 @@ pub fn window_by_2(l: List(a)) -> List(tuple(a, a)) { zip(l, drop(l, 1)) } -external fn erl_drop_while(fn(a) -> Bool, List(a)) -> List(a) = - "lists" "dropwhile" - /// Drops the first elements in a given list for which the predicate funtion returns `True`. /// /// ## Examples @@ -1234,12 +1231,16 @@ pub fn drop_while( in list: List(a), satisfying predicate: fn(a) -> Bool, ) -> List(a) { - erl_drop_while(predicate, list) + case list { + [] -> [] + [x, ..xs] -> + case predicate(x) { + True -> drop_while(xs, predicate) + False -> [x, ..xs] + } + } } -external fn erl_take_while(fn(a) -> Bool, List(a)) -> List(a) = - "lists" "takewhile" - /// Takes the first elements in a given list for which the predicate funtion returns `True`. /// /// ## Examples @@ -1251,5 +1252,12 @@ pub fn take_while( in list: List(a), satisfying predicate: fn(a) -> Bool, ) -> List(a) { - erl_take_while(predicate, list) + case list { + [] -> [] + [x, ..xs] -> + case predicate(x) { + True -> [x, ..take_while(xs, predicate)] + False -> [] + } + } } |