First you should check the universe repository
sudo gedit /etc/apt/sources.list and add
deb http://us.archive.ubuntu.com/ubuntu saucy main universe
line in sources.list if it is not in this file.
Then update : sudo apt-get update
Last install haskell :
sudo apt-get install haskell-platform
Now we try to write first haskell program and build it.
Firstly open a text editor and write
main = putStrLn "Hello, World!"
Then save as first.hs In terminal give command like this : ghc -o hello first.hs then ./hello
Welcome the Functional Programming World and Haskell.