On 20 June 2011 20:05, Jeremy Shaw
Hello,
How is this actually different from web-routes (which already supports automatic url deriving via Template Haskell, generics, or quasi-quotation)?
1) Erm, it's actually documented? ;-)
You suggest that web-routes requires a single URL type for all the routes and that your code allows for multiple types. But I do not see how that is actually done.
2) {-# LANGUAGE RecordWildCards, DeriveDataTypeable #-} import Data.Data import Data.List import Data.Maybe import Web.URL.Generic data Event = Event { eventId :: Integer -- ^ The event id. , eventScope :: Bool -- ^ Show the scope? , eventLayout :: Layout -- ^ Layout for the page. } deriving (Data,Typeable,Show) data Layout = Wide | Thin | Collapsed deriving (Typeable,Data,Show,Enum) data Home = Home deriving (Data,Typeable,Show) router :: String -> IO String router url = fromMaybe (error "404!") (listToMaybe $ mapMaybe ($ url) routes) routes :: [String -> Maybe (IO String)] routes = [route eventPage ,route homePage] route :: Data a => (a -> IO String) -> (String -> Maybe (IO String)) route handler url = case parseURLPath url of Just a -> Just $ handler a Nothing -> Nothing eventPage :: Event -> IO String eventPage Event{..} = return $ "Event page! Layout: " ++ show eventLayout homePage :: Home -> IO String homePage Home = return $ "Home page! Click here to go to the event page: " ++ formatURLPath Event { eventId = 1, eventScope = False, eventLayout = Thin } λ> router "/event/id/1/layout/wide" Loading package syb-0.1.0.2 ... linking ... done. Loading package transformers-0.2.2.0 ... linking ... done. Loading package mtl-2.0.1.0 ... linking ... done. "Event page! Layout: Wide" λ> router "/home" "Home page! Click here to go to the event page: /event/id/1/layout/thin" λ> router "" *** Exception: 404!