[Haskell-beginners] Re: how to define a user datatype consisting of instances of String?

On Thu, 23 Oct 2008 15:22:17 +0900, Benjamin L. Russell wrote:

Here's a slight revision; would this work?

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 <- sidedieshes == "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 <- sidedieshes == "garlic bread" = ("chicken", "garlic bread", "Merlot") | sidedish <- sidedieshes == "mozzarella sticks" = ("chicken", "mozzarella sticks", "Sauvignon Blanc") | sidedish <- sidedieshes == "caviar"= ("chicken", "caviar", "Merlot") | entree <- entrees == "tuna" = | sidedish <- sidedieshes == "garlic bread" = ("tuna", "garlic bread", "Sauvignon Blanc") | sidedish <- sidedieshes == "mozzarella sticks" = ("tuna", "mozzarella sticks", "Merlot") | sidedish <- sidedieshes == "caviar"= ("tuna", "caviar", "Merlot")

Sorry; my earlier revision contained some typos where "sidedishes" was misspelled as "sidedieshes." Here is a corrected version: 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") -- Benjamin L. Russell