Haskell - Recursive data type

Hello! I'm trying to make a recursive data type consisting of a char and a link to the next char, which means that it is a string. Then I am trying to make a function that searche throught the List for a specific character:

data Test = NULL |                          
            Word Char Test  
                
searchChar::Test->Char->IO ()  
searchChar str cha = do result <- makeIO (findChar str cha)
                        if result == cha
                           then putStr [result]
                           else putStr "Not Found"

findChar::Test->Char->Char  
findChar (Word cha NULL) cha2 
  | cha == cha2 = cha
  | otherwise = ' ' 

findChar (Word cha pNext) cha2
  | cha == cha2 = cha
  | otherwise = findChar pNext cha2


makeIO::a->IO (a)
makeIO val = return(val)

makeVal::a->a
makeVal val = val

But when I call for the searchChar function like this:

searchChar ('H' ('e' ('l' ('l' ('o' (NULL)))))) 'e'
  

I'm getting this error by the Hugs interpretor:

ERROR - Type error in application
*** Expression     : 'H' ('e' ('l' ('l' ('o' NULL))))
*** Term           : 'H'
*** Type           : Char
*** Does not match : a -> b
  

I know it is the findChar function it is complaining about... something about the type I have in the findChar function, but I can't seem to figure out what is so bad about it... [edited by - bilsa on October 9, 2003 1:29:38 PM]