map-syntax testing

mapK amnesia

module Main where

import qualified Data.Map as M
import Data.Map.Syntax

-- prints: Right (fromList [("blobz",10),("smootz",12)])

main = print . runMapSyntax M.lookup M.insert $ do
  foo
  mapK (++ "a") bar
  "extra" #! 1234
  mapK (++ "z") baz
  
foo = do
  "java" #! (1 :: Int)
  "haskel" #! 2

bar = do
  "c" #! 1
  "haskell" #! 3

baz = do
  "blob" #! 10
  "smoot" #! 12