Re: [Haskell-cafe] Mixing IO and STM

Also, if you are trying to display a line that looks like insert 5 or consume 6 then consider using

putStrLn ("insert " ++ show r) putStrLn ("consume " ++ show r)

instead of

print ("insert " ++ show r) print ("consume " ++ show r)

to avoid printing out the extra quotation marks. The function print is defined in the prelude as

print :: Show a => a -> IO () print x = putStrLn (show x)

also, you could do:

putStrLn $ "insert " ++ show r

because the $ infix operator is just a tightly binding function application... you can think of it as a sort of left parenthesis that automatically adds a right parenthesis at the end of your expression. Jared.