Create Setter.hs

Author: ztk37

haskell/Setter.hs

@@ -0,0 +1,25 @@
+module Main (main) where
+
+data Record = Record
+  { recordA :: String
+  , recordB :: String
+  , recordC :: String
+  } deriving (Show)
+
+setter :: String -> String -> Record -> Record
+setter "a" v r = r { recordA = v }
+setter "b" v r = r { recordB = v }
+setter "c" v r = r { recordC = v }
+setter _ _ r = r
+
+xs :: [(String, String)]
+xs =
+  [ ("a", "damn")
+  , ("c", "fib")
+  , ("g", "derp")
+  , ("b", "bar")
+  , ("a", "foo")
+  ]
+    
+main :: IO ()
+main = print $ foldr (\(k, v) r -> setter k v r) (Record "" "" "") xs