Data.ListのByつき関数
Data.ListにはByつき関数がありますが、ないものとあるものを並べてみました。
対応関係としては、
- Eq a が a -> a -> Bool
- Ord a が a -> a -> Ordering
となっています。
| 関数 | 型 | Byつき関数 | 型 |
|---|---|---|---|
| nub | Eq a => [a] -> [a] | nubBy | (a -> a -> Bool) -> [a] -> [a] |
| delete | Eq a => a -> [a] -> [a] | deleteBy | (a -> a -> Bool) -> a -> [a] -> [a] |
| (\\) | Eq a => [a] -> [a] -> [a] | deleteFirstsBy | (a -> a -> Bool) -> [a] -> [a] -> [a] |
| union | Eq a => [a] -> [a] -> [a] | unionBy | (a -> a -> Bool) -> [a] -> [a] -> [a] |
| intersect | Eq a => [a] -> [a] -> [a] | intersectBy | (a -> a -> Bool) -> [a] -> [a] -> [a] |
| group | Eq a => [a] -> a | groupBy | (a -> a -> Bool) -> [a] -> a |
| sort | Ord a => [a] -> [a] | sortBy | (a -> a -> Ordering) -> [a] -> [a] |
| insert | Ord a => a -> [a] -> [a] | insertBy | (a -> a -> Ordering) -> a -> [a] -> [a] |
| maximum | Ord a => [a] -> a | maximumBy | (a -> a -> Ordering) -> [a] -> a |
| minimum | Ord a => [a] -> a | minimumBy | (a -> a -> Ordering) -> [a] -> a |
(//)とdeleteFirstsByが対応している点が関数名からはわかりにくいですねぇ。
