How to resolve issues when getting error: Not in scope

Question

*Main> :t putStrn

<interactive>:1:1:
Not in scope: `putStrn'
Perhaps you meant one of these:  
  `putStr' (imported from Prelude),  
  `putStrLn' (imported from Prelude)

Please note that I am practising haskell programming in emacs with haskell mode.

Even while using terminal, I am getting following error:

optimight@optimight:~$ ghci  
GHCi, version 7.4.1: http://www.haskell.org/ghc/  :? for help  
Loading package ghc-prim ... linking ... done. 
Loading package integer-gmp ... linking ... done.  
Loading package base ... linking ... done.  
Prelude> :set prompt ghci>  
ghci>:t putStrln   

<interactive>:1:1:  
    Not in scope: `putStrln'  
    Perhaps you meant one of these:  
      `putStrLn' (imported from Prelude),  
      `putStr' (imported from Prelude)

@Pikaurd: Yes, I am using after refering to the book- Learn you a Haskell for Good - topic 9.1 where it has written "Let's examine what we wrote. First, let's look at the type of the function putStrLn. ghci> :t putStrLn putStrLn :: String -> IO () ghci> :t putStrLn "hello, world" putStrLn "hello, world" :: IO () — Optimight
putStrn and putStrln are a different names than putStrLn. — ephemient

Greg Bacon Greg Bacon · Accepted Answer · 2012-07-29T01:20:11

The I/O action you are looking for is putStrLn. Note the capital L — Haskell symbols are case-sensitive — just before the final n, as in “put a string on a line of its own.”.

How to resolve issues when getting error: Not in scope

1 Answers