lib and main in separated modules

Main.hs

@@ -0,0 +1,31 @@
+#!/usr/bin/env runhaskell
+
+import RecipeCost
+
+-- * Example (in french for now)
+eau = Ingredient "Eau" 0.003
+savonMarseille = Ingredient "Savon de Marseille" 3.36
+bicarbonate = Ingredient "Bicarbonate de soude" 3.81
+vinaigreBlanc = Ingredient "Vinaigre blanc" 0.36
+
+lessive :: Recipe
+lessive = Recipe "Lessive"
+                 [ eau → 2.5
+                 , savonMarseille → 0.1
+                 , bicarbonate → 0.016
+                 , vinaigreBlanc → 0.03
+                 ]
+                 2.5
+                 30
+
+main = do
+    putStrLn "Calcul du coût des recettes\n"
+    putStrLn "* Lessive :"
+    print lessive
+    let lessiveTotalCost = recipeCost lessive
+        lessiveUnitCost = unitCost lessive lessiveTotalCost
+        lessiveUseCost = useCost lessive lessiveTotalCost
+    putStrLn $ "  * Prix Total = " ++ show lessiveTotalCost ++ "€"
+    putStrLn $ "  * Prix au litre = " ++ show lessiveUnitCost ++ "€"
+    putStrLn $ "  * Prix par utilisation = " ++ show lessiveUseCost ++ "€"
+

RecipeCost.hs

@@ -1,4 +1,4 @@
-#! /usr/bin/env runhaskell
+module RecipeCost where
 
 -- * Data types definition
 data Ingredient = Ingredient { ingredientName :: String
@@ -28,31 +28,3 @@ useCost (Recipe _ _ _ uses) totalCost = totalCost / uses
 
 (→) :: Ingredient -> Double -> UsedIngredient
 (→) ingredient qtt = UsedIngredient ingredient qtt
-
--- * Example (in french for now)
-eau = Ingredient "Eau" 0.003
-savonMarseille = Ingredient "Savon de Marseille" 3.36
-bicarbonate = Ingredient "Bicarbonate de soude" 3.81
-vinaigreBlanc = Ingredient "Vinaigre blanc" 0.36
-
-lessive :: Recipe
-lessive = Recipe "Lessive"
-                 [ eau → 2.5
-                 , savonMarseille → 0.1
-                 , bicarbonate → 0.016
-                 , vinaigreBlanc → 0.03
-                 ]
-                 2.5
-                 30
-
-main = do
-    putStrLn "Calcul du coût des recettes\n"
-    putStrLn "* Lessive :"
-    print lessive
-    let lessiveTotalCost = recipeCost lessive
-        lessiveUnitCost = unitCost lessive lessiveTotalCost
-        lessiveUseCost = useCost lessive lessiveTotalCost
-    putStrLn $ "  * Prix Total = " ++ show lessiveTotalCost ++ "€"
-    putStrLn $ "  * Prix au litre = " ++ show lessiveUnitCost ++ "€"
-    putStrLn $ "  * Prix par utilisation = " ++ show lessiveUseCost ++ "€"
-