Install haskell and your first program Guess Number

Build Tools

Nix

Stack

https://docs.haskellstack.org/en/stable/README/

make sure stack --version outputs latest stack version, currently Version 1.6.5.

stack upgrade

Editor Integration

VScode with haskell-ide-engine

Haskell Syntax Highlight

haskell-ide-engine

Install on MacOS, you need to install icu4c on your machine.

git clone https://github.com/haskell/haskell-ide-engine
cd haskell-ide-engine
make

Old way

brew install icu4c && brew link icu4c --force
stack install text-icu --extra-lib-dirs=/usr/local/opt/icu4c/lib --extra-include-dirs=/usr/local/opt/icu4c/include

stack install hoogle

hoogle generate
stack install

Stack

stack version

stack upgrade

Your first haskell program

stack new guessNumber simple

module Main where

import           Control.Monad
import           Data.Ord      (compare)
import           System.IO     (readLn)
import           System.Random (randomRIO)


guess :: Int -> IO ()
guess secretNumber = do
    print "guess a number"
    guessNumber <- readLn :: IO Int
    case compare guessNumber secretNumber of
        LT -> (print "Too Small!") >> (guess secretNumber)
        EQ -> print "You Win!"
        GT -> (print "Too big!") >> (guess secretNumber)


main :: IO ()
main = do
    secretNumber <- randomRIO (0, 100) :: IO Int
    guess secretNumber