Find first SO chat message in Haskell

Question

I have made some simple functions to find the first SO chat message. How can I improve my code?

Even if there is a stackoverflow link that will get the job done (I'd be glad to know), I'd like to improve upon my already written code.

import Network.HTTP
import Text.Regex.Posix
type UserID = String
type MessageLink = String
type PageNumber = Integer
findLast :: UserID -> IO MessageLink
findLast = searchLast 1 "Not found" 
searchLast :: PageNumber -> MessageLink -> UserID -> IO MessageLink 
searchLast pg lnk id = do
 let link = "http://chat.stackoverflow.com/users/" ++
 id ++ "?tab=recent&page=" ++ show pg 
 c <- simpleHTTP (getRequest link) >>= getResponseBody
 let match = c =~ "/transcript/[^\"]+" :: [[String]]
 if null (c =~ "monologue" :: String)
 then return $ "http://chat.stackoverflow.com" ++ lnk
 else searchLast (pg + 1) (head . last $ match) id

• 200_success: Follow-up question

Answer 1

• Avoid partial functions like head and last.
• http://chat.stackoverflow.com is repeated twice in searchLast. Maybe throw it into its own let-binding to make the function more DRY.