hw2: init

hw2/hs/mapExample.hs

@@ -0,0 +1,12 @@
+import Data.Map (Map)
+import qualified Data.Map as Map
+
+m = Map.empty
+
+m' = Map.insert "a" 42 m
+
+main = do
+  case (Map.lookup "a" m') of
+    Just i -> putStrLn $ show i
+    _      -> error "Key is not in the map"
+