容器中有什么东西可以让我获得Data.Set的子集吗？

Question

我找不到任何给定min和max的函数返回容器中任何结构的该间隔中的所有值。当然必须有......？

Answer 1

inRange :: Ord a => a -> a -> Set a -> Set a
inRange min max s = fst $ S.split max gt
  where (_, gt) = S.split min s

Answer 2

您可以使用Data.Set.filter

轻松编写此内容

import Data.Set (Set)
import qualified Data.Set as S

between :: Ord a => a -> a -> Set a -> Set a
between min_ max_ = S.filter (\x -> min_ <= x && x <= max_)

然后你可以用它作为

> between 3 7 $ S.fromList [1..10]
fromList [3, 4, 5, 6, 7]