snap-web-routes-0.3.0.0: Type safe URLs for Snap

Safe HaskellNone

Snap.Web.Routes.Types

Synopsis

Documentation

gets :: MonadState s m => (s -> a) -> m a

Gets specific component of the state, using a projection function supplied.

class Generic a

Representable types of kind *. This class is derivable in GHC with the DeriveGeneric flag on.

Instances

Generic Bool 
Generic Char 
Generic Double 
Generic Float 
Generic Int 
Generic Ordering 
Generic () 
Generic Void 
Generic [a] 
Generic (Maybe a) 
Generic (Max a) 
Generic (First a) 
Generic (Last a) 
Generic (WrappedMonoid m) 
Generic (Option a) 
Generic (Either a b) 
Generic (a, b) 
Generic (a, b, c) 
Generic (a, b, c, d) 
Generic (a, b, c, d, e) 
Generic (a, b, c, d, e, f) 
Generic (a, b, c, d, e, f, g) 

class Monad m => MonadRoute m where

Associated Types

type URL m1 :: *

Methods

askRouteFn :: m (URL m -> [(Text, Maybe Text)] -> Text)

Instances

MonadRoute m => MonadRoute (HeistT n m)

MonadRoute instance for HeistT.

Monad m => MonadRoute (RouteT url m) 

class PathInfo url where

Simple parsing and rendering for a type to and from URL path segments.

If you're using GHC 7.2 or later, you can use DeriveGeneric to derive instances of this class: 

 {-# LANGUAGE DeriveGeneric #-}
 data Sitemap = Home | BlogPost Int deriving Generic
 instance PathInfo Sitemap

This results in the following instance: 

 instance PathInfo Sitemap where
     toPathSegments Home = ["home"]
     toPathSegments (BlogPost x) = "blog-post" : toPathSegments x
     fromPathSegments = Home <$ segment "home"
                    <|> BlogPost <$ segment "blog-post" <*> fromPathSegments

And here it is in action: 

>>> toPathInfo (BlogPost 123)
"/blog-post/123"
>>> fromPathInfo "/blog-post/123" :: Either String Sitemap
Right (BlogPost 123)

To instead derive instances using TemplateHaskell, see web-routes-th.

Methods

toPathSegments :: url -> [Text]

fromPathSegments :: URLParser url

Instances