Expanding the abbreviated words from a file in Haskell - haskell

Question

I am new at working with files in haskell.I wrote a code to check for occurence of words in a .c file. words are listed in a .txt file .
for example:
abbreviations.txt
ix=index
ctr=counter
tbl=table
Another file is:
main.c
main ()
{
ix = 1
for (ctr =1; ctr < 10; ctr++)
{
tbl[ctr] = ix
}
}
on encountering ix it should be expanded to index and same for ctr and tbl.
This is the code I wrote to check for occurrences(not yet to replace the encountered words)
import System.Environment
import System.IO
import Data.Char
import Control.Monad
import Data.Set
main = do
s <- getLine
f <- readFile "abbreviations.txt"
g <- readFile s
let dict = fromList (lines f)
mapM_ (spell dict) (words g)
spell d w = when (w `member` d) (putStrLn w)
On executing the code it is giving no output.
Instead of the upper code,I tried reading a file using hgetLine then converting it into list of words using words
getLines' h = do
isEOF <- hIsEOF h
if isEOF then
return ()
else
do
line <- hGetLine h
list<-remove (return (words line))
getLines' h
-- print list
main = do
inH <- openFile "abbreviations.txt" ReadMode
getLines' inH
hClose inH
remove [] = []
remove (x:xs)| x == "=" = remove xs
| otherwise = x:remove (xs)
But its giving me errors relating to IO() ,is there any other way in which I could do the following.
Where am I going wrong?
Thank you for any help.

Answer 1

First, there is a problem with your spell function. It should also have an else clause with it:
spell :: (Show a, Ord a) => Set a -> a -> IO ()
spell d w = if (w `member` d)
then print d
else return ()
Also, note that I have changed your putStrLn to print and added a type signature to your code.
On executing the code it is giving no output.
That's because, it's always going to the else clause in your spell function. If you try to trace up the execution of your program, then you will note that, your dict variable will actually contain this Set: ["ctr=counter","ix=index","tbl=table"] and it doesn't contains the words of the file main.c. I hope this will be sufficient to get you started.