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  1. import qualified Data.Map as Map
  2. import Debug.Trace (trace)
  3. import Text.Show.Functions
  4.  
  5. main = do
  6.     print $ findWithDefault 123 "a" mapdata
  7.     print $ findWithDefault 123 "e" mapdata
  8.  
  9. mapdata = Map.fromList [("a", 123),("b",456),("c",999)]
  10.  
  11. findWithDefault = curry.(.uncurry Map.lookup).(`maybe` trace "existed").(trace "default")
  12.  
  13.  
Success #stdin #stdout #stderr 0s 8388607KB
comments (?)
stdin 
Standard input is empty
stdout 
123
123
stderr 
existed
default
https://ideone.com/RVpv4o
language:
Haskell (ghc 8.4.4)
created:
6 years ago
visibility:
public

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