Difference between revisions of "Implicit parameters"
Jump to navigation
Jump to search
m (Fix link to GHC doc) |
|||
| Line 7: | Line 7: | ||
import Data.List (sortBy) |
import Data.List (sortBy) |
||
| − | + | sortBy' :: (?cmp :: a -> a -> Ordering) => [a] -> [a] |
|
| − | + | sortBy' = sortBy ?cmp |
|
| + | |||
| + | sort :: Ord a => [a] -> [a] |
||
| + | sort = let ?cmp = compare in sortBy' |
||
| − | main = |
+ | main = putStrLn (show (sort [3,1,2])) |
[[Category:Language extensions]] |
[[Category:Language extensions]] |
||
Revision as of 14:19, 9 July 2016
The GHC manual on implicit parameters: [1].
Working example:
{-# LANGUAGE ImplicitParams #-}
import Data.List (sortBy)
sortBy' :: (?cmp :: a -> a -> Ordering) => [a] -> [a]
sortBy' = sortBy ?cmp
sort :: Ord a => [a] -> [a] sort = let ?cmp = compare in sortBy' main = putStrLn (show (sort [3,1,2]))