yesod/yesod-core/test/YesodCoreTest/ParameterizedSite/PolyShow.hs

29 lines
597 B
Haskell

{-# LANGUAGE
TypeFamilies, QuasiQuotes, TemplateHaskell, MultiParamTypeClasses
, OverloadedStrings, StandaloneDeriving, FlexibleInstances
#-}
module YesodCoreTest.ParameterizedSite.PolyShow
( PolyShow (..)
) where
import Yesod.Core
-- | Parameterized with 'Show' constraint
data PolyShow a = PolyShow a
mkYesod "(Show a) => PolyShow a" [parseRoutes|
/ HomeR GET
|]
instance Show a => Yesod (PolyShow a)
getHomeR :: Show a => Handler a Html
getHomeR = do
PolyShow x <- getYesod
defaultLayout
[whamlet|
<p>
Stub #{show x}
|]