Implicit parameters: Difference between revisions
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{{GHCUsersGuide| | {{GHCUsersGuide|glasgow_exts|implicit-parameters|Implicit Parameters section}} | ||
Working example: | Working example: |
Revision as of 23:03, 13 November 2016
The GHC Users Guide has Implicit Parameters section.
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]))