Initial version

app/Main.hs

 module Main where
 
+import Control.Monad
 import Lib
 
 main :: IO ()
-main = someFunc
+main = do
+  putStrLn "How many random integer numbers should we generate?"
+  count <- read <$> getLine :: IO Int
+  
+  putStrLn "What would be the minimum value of those numbers?"
+  min <- read <$> getLine :: IO Int
+  
+  putStrLn "What would be the maximum value of those numbers?"
+  max <- read <$> getLine :: IO Int
+
+  if count <= 0 then error "The count must be a positive number"
+  else if max < min then error "The minimum cannot be larger than the maximum"
+  else putStrLn $ "Very well, producing " ++
+                 (if count == 1 then "a number" else show count ++ " numbers") ++
+                 " between " ++ show min ++ " and " ++ show max ++ "!"
+  
+  putStrLn $ "In real life, we could emulate that with " ++
+             show count ++ " x " ++
+             show (max-min+1) ++ " sided dice rolls."
+             
+  forM_ [1..count] (generateNumber min max)
+

package.yaml

@@ -21,6 +21,7 @@ description:         Please see the README on GitHub at <https://github.com/gith
 
 dependencies:
 - base >= 4.7 && < 5
+- random >= 1.1
 
 library:
   source-dirs: src

src/Lib.hs

 module Lib
-    ( someFunc
+    ( generateNumber
     ) where
 
-someFunc :: IO ()
-someFunc = putStrLn "someFunc"
+import System.Random (randomRIO)
+
+generateNumber:: Int -> Int -> Int -> IO ()
+generateNumber min max n = do
+   number <- randomRIO (min, max) -- :: IO Integer  
+   putStrLn $ "The number " ++ show n ++ " is " ++ show number
+

twenty-one.cabal

@@ -4,7 +4,7 @@ cabal-version: 1.12
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: c82d45f7d53e0e4b5e6b1efd72b97d7d54433e71dd7cb846abcf37807b183ff3
+-- hash: cb97234e42a0696981bd86c74f9a64d2fa737b556dcddec6373e905d67968bf1
 
 name:           twenty-one
 version:        0.1.0.0
@@ -34,6 +34,7 @@ library
       src
   build-depends:
       base >=4.7 && <5
+    , random >=1.1
   default-language: Haskell2010
 
 executable twenty-one-exe
@@ -45,6 +46,7 @@ executable twenty-one-exe
   ghc-options: -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       base >=4.7 && <5
+    , random >=1.1
     , twenty-one
   default-language: Haskell2010
 
@@ -58,5 +60,6 @@ test-suite twenty-one-test
   ghc-options: -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       base >=4.7 && <5
+    , random >=1.1
     , twenty-one
   default-language: Haskell2010