search.hs

import Data.List

data Person = Person { name, address :: String} deriving Show

ps = [ Person "Tarou" "Tokyo"
     , Person "Jirou" "Osaka"
     , Person "Saburou" "Nagoya"
     ]

getAddress n ps = case find ((== n) . name) ps of
                    Just x  -> address x
                    Nothing -> n ++ " ha imasen"

main =  mapM_ (putStrLn . flip getAddress ps) ["Tarou","Hanako"]