On Thu, 23 Oct 2008 15:27:34 +0900, Benjamin L.Russell
module Wine where
data Wine = Red | White data Red = "Merlot" data White = "Sauvignon Blanc" data Entree = "pork" | "chicken" | "tuna" data SideDish = "garlic bread" | "mozzarella sticks" | "caviar"
wine :: [Entree] -> [SideDish] -> [(Entree, SideDish, Wine)] wine entrees sidedishes | entree <- entrees == "pork" = | sidedish <- sidedishes == "garlic bread" = ("pork", "garlic bread", "Merlot") | sidedish <- sidedishes == "mozzarella sticks" = ("pork", "mozzarella sticks", "Merlot") | sidedish <- sidedishes == "caviar" = ("pork", "caviar", "Sauvignon Blanc") | entree <- entrees == "chicken" = | sidedish <- sidedishes == "garlic bread" = ("chicken", "garlic bread", "Merlot") | sidedish <- sidedishes == "mozzarella sticks" = ("chicken", "mozzarella sticks", "Sauvignon Blanc") | sidedish <- sidedishes == "caviar"= ("chicken", "caviar", "Merlot") | entree <- entrees == "tuna" = | sidedish <- sidedishes == "garlic bread" = ("tuna", "garlic bread", "Sauvignon Blanc") | sidedish <- sidedishes == "mozzarella sticks" = ("tuna", "mozzarella sticks", "Merlot") | sidedish <- sidedishes == "caviar"= ("tuna", "caviar", "Merlot")
I just thought of a revision using the guards within an instance of unlines and map. This approach eliminates the need for the Wine, Red, and White datatypes. However, since two elements of type String need to be extracted at each step, I am not sure of the syntax. Would this approach a solution? module Wine where data Entree = "pork" | "chicken" | "tuna" data SideDish = "garlic bread" | "mozzarella sticks" | "caviar" wine :: Show a => [Entree] -> [SideDish] -> String wine entrees sidedishes = unlines (map entree entrees) (map sidedish sidedishes) where (entree Entree) (sidedish SideDish) = | entree == "pork" = | sidedish == "garlic bread" = "(" ++ show entree ++ ", " ++ show sidedish ++ ", Merlot)" | sidedish == "mozzarella sticks" = "(" ++ show entree ++ ", " ++ show sidedish ++ ", Merlot)" | sidedish == "caviar" = "(" ++ show entree ++ ", " ++ show sidedish ++ ", Sauvignon Blanc)" | entree == "chicken" = | sidedish == "garlic bread" = "(" ++ show entree ++ ", " ++ show sidedish ++ ", Merlot)" | sidedish == "mozzarella sticks" = "(" ++ show entree ++ ", " ++ show sidedish ++ ", Sauvignon Blanc)" | sidedish == "caviar"= "(" ++ show entree ++ ", " ++ show sidedish ++ ", Merlot)" | entree == "tuna" = | sidedish == "garlic bread" = "(" ++ show entree ++ ", " ++ show sidedish ++ ", Sauvignon Blanc)" | sidedish == "mozzarella sticks" = "(" ++ show entree ++ ", " ++ show sidedish ++ ", Merlot)" | sidedish == "caviar"= "(" ++ show entree ++ ", " ++ show sidedish ++ ", Merlot)" -- Benjamin L. Russell