Cleanup GHC 8 redundant constraints

yesod-auth-oauth/Yesod/Auth/OAuth.hs

@@ -83,7 +83,7 @@ authOAuth oauth mkCreds = AuthPlugin name dispatch login
         let oaUrl = render $ tm $ oauthUrl name
         [whamlet| <a href=#{oaUrl}>Login via #{name} |]
 
-mkExtractCreds :: YesodAuth m => Text -> String -> Credential -> IO (Creds m)
+mkExtractCreds :: Text -> String -> Credential -> IO (Creds m)
 mkExtractCreds name idName (Credential dic) = do
   let mcrId = decodeUtf8With lenientDecode <$> lookup (encodeUtf8 $ T.pack idName) dic
   case mcrId of

yesod-auth/Yesod/Auth.hs

@@ -167,7 +167,7 @@ class (Yesod master, PathPiece (AuthId master), RenderMessage master FormMessage
     -- >             lift $ redirect HomeR   -- or any other Handler code you want
     -- >         defaultLoginHandler
     -- 
-    loginHandler :: AuthHandler master Html
+    loginHandler :: HandlerT Auth (HandlerT master IO) Html
     loginHandler = defaultLoginHandler
 
     -- | Used for i18n of messages provided by this package.

yesod-auth/Yesod/Auth/Email.hs

@@ -297,7 +297,7 @@ class ( YesodAuth site
     -- Default: 'defaultRegisterHandler'.
     --
     -- @since: 1.2.6
-    registerHandler :: AuthHandler site Html
+    registerHandler :: HandlerT Auth (HandlerT site IO) Html
     registerHandler = defaultRegisterHandler
 
     -- | Handler called to render the \"forgot password\" page.
@@ -307,7 +307,7 @@ class ( YesodAuth site
     -- Default: 'defaultForgotPasswordHandler'.
     --
     -- @since: 1.2.6
-    forgotPasswordHandler :: AuthHandler site Html
+    forgotPasswordHandler :: HandlerT Auth (HandlerT site IO) Html
     forgotPasswordHandler = defaultForgotPasswordHandler
 
     -- | Handler called to render the \"set password\" page.  The
@@ -323,7 +323,7 @@ class ( YesodAuth site
          -- field for the old password should be presented.
          -- Otherwise, just two fields for the new password are
          -- needed.
-      -> AuthHandler site TypedContent
+      -> HandlerT Auth (HandlerT site IO) TypedContent
     setPasswordHandler = defaultSetPasswordHandler
 
 authEmail :: (YesodAuthEmail m) => AuthPlugin m
@@ -405,7 +405,7 @@ emailLoginHandler toParent = do
 -- | Default implementation of 'registerHandler'.
 --
 -- @since 1.2.6
-defaultRegisterHandler :: YesodAuthEmail master => AuthHandler master Html
+defaultRegisterHandler :: YesodAuthEmail master => HandlerT Auth (HandlerT master IO) Html
 defaultRegisterHandler = do
     (widget, enctype) <- lift $ generateFormPost registrationForm
     toParentRoute <- getRouteToParent
@@ -502,7 +502,7 @@ getForgotPasswordR = forgotPasswordHandler
 -- | Default implementation of 'forgotPasswordHandler'.
 --
 -- @since 1.2.6
-defaultForgotPasswordHandler :: YesodAuthEmail master => AuthHandler master Html
+defaultForgotPasswordHandler :: YesodAuthEmail master => HandlerT Auth (HandlerT master IO) Html
 defaultForgotPasswordHandler = do
     (widget, enctype) <- lift $ generateFormPost forgotPasswordForm
     toParent <- getRouteToParent
@@ -636,7 +636,7 @@ getPasswordR = do
 -- | Default implementation of 'setPasswordHandler'.
 --
 -- @since 1.2.6
-defaultSetPasswordHandler :: YesodAuthEmail master => Bool -> AuthHandler master TypedContent
+defaultSetPasswordHandler :: YesodAuthEmail master => Bool -> HandlerT Auth (HandlerT master IO) TypedContent
 defaultSetPasswordHandler needOld = do
     messageRender <- lift getMessageRender
     toParent <- getRouteToParent
@@ -823,7 +823,10 @@ loginLinkKey = "_AUTH_EMAIL_LOGIN_LINK"
 -- | Set 'loginLinkKey' to the current time.
 --
 -- @since 1.2.1
-setLoginLinkKey :: (YesodAuthEmail site, MonadHandler m, HandlerSite m ~ site) => AuthId site -> m ()
+--setLoginLinkKey :: (MonadHandler m) => AuthId site -> m ()
+setLoginLinkKey :: (MonadHandler m, YesodAuthEmail (HandlerSite m))
+                => AuthId (HandlerSite m)
+                -> m ()
 setLoginLinkKey aid = do
     now <- liftIO getCurrentTime
     setSession loginLinkKey $ TS.pack $ show (toPathPiece aid, now)

yesod-auth/Yesod/Auth/GoogleEmail.hs

@@ -71,7 +71,7 @@ authGoogleEmail =
         completeHelper posts
     dispatch _ _ = notFound
 
-completeHelper :: YesodAuth master => [(Text, Text)] -> AuthHandler master TypedContent
+completeHelper :: [(Text, Text)] -> AuthHandler master TypedContent
 completeHelper gets' = do
       master <- lift getYesod
       eres <- lift $ try $ OpenId.authenticateClaimed gets' (authHttpManager master)

yesod-core/Yesod/Core/Class/Yesod.hs

@@ -442,10 +442,9 @@ sameSiteSession s = (fmap . fmap) secureSessionCookies
 -- headers are ignored over HTTP.
 --
 -- Since 1.4.7
-sslOnlyMiddleware :: Yesod site
-                     => Int -- ^ minutes
-                     -> HandlerT site IO res
-                     -> HandlerT site IO res
+sslOnlyMiddleware :: Int -- ^ minutes
+                  -> HandlerT site IO res
+                  -> HandlerT site IO res
 sslOnlyMiddleware timeout handler = do
     addHeader "Strict-Transport-Security"
               $ T.pack $ concat [ "max-age="
@@ -496,8 +495,7 @@ defaultCsrfCheckMiddleware handler =
 -- For details, see the "AJAX CSRF protection" section of "Yesod.Core.Handler".
 --
 -- Since 1.4.14
-csrfCheckMiddleware :: Yesod site
-                    => HandlerT site IO res
+csrfCheckMiddleware :: HandlerT site IO res
                     -> HandlerT site IO Bool -- ^ Whether or not to perform the CSRF check.
                     -> CI S8.ByteString -- ^ The header name to lookup the CSRF token from.
                     -> Text -- ^ The POST parameter name to lookup the CSRF token from.
@@ -512,7 +510,7 @@ csrfCheckMiddleware handler shouldCheckFn headerName paramName = do
 -- The cookie's path is set to @/@, making it valid for your whole website.
 --
 -- Since 1.4.14
-defaultCsrfSetCookieMiddleware :: Yesod site => HandlerT site IO res -> HandlerT site IO res
+defaultCsrfSetCookieMiddleware :: HandlerT site IO res -> HandlerT site IO res
 defaultCsrfSetCookieMiddleware handler = setCsrfCookie >> handler
 
 -- | Takes a 'SetCookie' and overrides its value with a CSRF token, then sets the cookie. See 'setCsrfCookieWithCookie'.
@@ -522,7 +520,7 @@ defaultCsrfSetCookieMiddleware handler = setCsrfCookie >> handler
 -- Make sure to set the 'setCookiePath' to the root path of your application, otherwise you'll generate a new CSRF token for every path of your app. If your app is run from from e.g. www.example.com\/app1, use @app1@. The vast majority of sites will just use @/@.
 --
 -- Since 1.4.14
-csrfSetCookieMiddleware :: Yesod site => HandlerT site IO res -> SetCookie -> HandlerT site IO res
+csrfSetCookieMiddleware :: HandlerT site IO res -> SetCookie -> HandlerT site IO res
 csrfSetCookieMiddleware handler cookie = setCsrfCookieWithCookie cookie >> handler
 
 -- | Calls 'defaultCsrfSetCookieMiddleware' and 'defaultCsrfCheckMiddleware'.
@@ -546,7 +544,7 @@ defaultCsrfMiddleware :: Yesod site => HandlerT site IO res -> HandlerT site IO
 defaultCsrfMiddleware = defaultCsrfSetCookieMiddleware . defaultCsrfCheckMiddleware
 
 -- | Convert a widget to a 'PageContent'.
-widgetToPageContent :: (Eq (Route site), Yesod site)
+widgetToPageContent :: Yesod site
                     => WidgetT site IO ()
                     -> HandlerT site IO (PageContent (Route site))
 widgetToPageContent w = do

yesod-core/Yesod/Core/Handler.hs

@@ -1119,13 +1119,13 @@ lookupPostParam :: (MonadResource m, MonadHandler m)
 lookupPostParam = fmap listToMaybe . lookupPostParams
 
 -- | Lookup for POSTed files.
-lookupFile :: (MonadHandler m, MonadResource m)
+lookupFile :: MonadHandler m
            => Text
            -> m (Maybe FileInfo)
 lookupFile = fmap listToMaybe . lookupFiles
 
 -- | Lookup for POSTed files.
-lookupFiles :: (MonadHandler m, MonadResource m)
+lookupFiles :: MonadHandler m
             => Text
             -> m [FileInfo]
 lookupFiles pn = do

yesod-core/Yesod/Core/Json.hs

@@ -189,7 +189,7 @@ jsonEncodingOrRedirect :: (MonadHandler m, J.ToJSON a)
 jsonEncodingOrRedirect = jsonOrRedirect' J.toEncoding
 #endif
 
-jsonOrRedirect' :: (MonadHandler m, J.ToJSON a)
+jsonOrRedirect' :: MonadHandler m
             => (a -> b)
             -> Route (HandlerSite m) -- ^ Redirect target
             -> a            -- ^ Data to send via JSON

yesod-core/Yesod/Core/Types.hs

@@ -462,7 +462,12 @@ instance MonadMask m => MonadMask (WidgetT site m) where
     WidgetT $ \e -> uninterruptibleMask $ \u -> unWidgetT (a $ q u) e
       where q u (WidgetT b) = WidgetT (u . b)
 
+-- CPP to avoid a redundant constraints warning
+#if MIN_VERSION_base(4,9,0)
+instance (MonadIO m, MonadBase IO m, MonadThrow m) => MonadResource (WidgetT site m) where
+#else
 instance (Applicative m, MonadIO m, MonadBase IO m, MonadThrow m) => MonadResource (WidgetT site m) where
+#endif
     liftResourceT f = WidgetT $ \hd -> liftIO $ (, mempty) <$> runInternalState f (handlerResource hd)
 
 instance MonadIO m => MonadLogger (WidgetT site m) where

yesod-form/Yesod/Form/Fields.hs

@@ -439,13 +439,13 @@ $newline never
 |]) -- inside
 
 -- | Creates a @\<select>@ tag for selecting multiple options.
-multiSelectFieldList :: (Eq a, RenderMessage site FormMessage, RenderMessage site msg)
+multiSelectFieldList :: (Eq a, RenderMessage site msg)
                      => [(msg, a)]
                      -> Field (HandlerT site IO) [a]
 multiSelectFieldList = multiSelectField . optionsPairs
 
 -- | Creates a @\<select>@ tag for selecting multiple options.
-multiSelectField :: (Eq a, RenderMessage site FormMessage)
+multiSelectField :: Eq a
                  => HandlerT site IO (OptionList a)
                  -> Field (HandlerT site IO) [a]
 multiSelectField ioptlist =
@@ -477,12 +477,12 @@ radioFieldList :: (Eq a, RenderMessage site FormMessage, RenderMessage site msg)
 radioFieldList = radioField . optionsPairs
 
 -- | Creates an input with @type="checkbox"@ for selecting multiple options.
-checkboxesFieldList :: (Eq a, RenderMessage site FormMessage, RenderMessage site msg) => [(msg, a)]
+checkboxesFieldList :: (Eq a, RenderMessage site msg) => [(msg, a)]
                      -> Field (HandlerT site IO) [a]
 checkboxesFieldList = checkboxesField . optionsPairs
 
 -- | Creates an input with @type="checkbox"@ for selecting multiple options.
-checkboxesField :: (Eq a, RenderMessage site FormMessage)
+checkboxesField :: Eq a
                  => HandlerT site IO (OptionList a)
                  -> Field (HandlerT site IO) [a]
 checkboxesField ioptlist = (multiSelectField ioptlist)
@@ -569,7 +569,7 @@ $newline never
 --
 --   Note that this makes the field always optional.
 --
-checkBoxField :: Monad m => RenderMessage (HandlerSite m) FormMessage => Field m Bool
+checkBoxField :: Monad m => Field m Bool
 checkBoxField = Field
     { fieldParse = \e _ -> return $ checkBoxParser e
     , fieldView  = \theId name attrs val _ -> [whamlet|
@@ -757,7 +757,7 @@ selectFieldHelper outside onOpt inside opts' = Field
                     Just y -> Right $ Just y
 
 -- | Creates an input with @type="file"@.
-fileField :: (Monad m, RenderMessage (HandlerSite m) FormMessage)
+fileField :: Monad m
           => Field m FileInfo
 fileField = Field
     { fieldParse = \_ files -> return $
@@ -803,7 +803,6 @@ $newline never
     return (res, (fv :), ints', Multipart)
 
 fileAFormOpt :: MonadHandler m
-             => RenderMessage (HandlerSite m) FormMessage
              => FieldSettings (HandlerSite m)
              -> AForm m (Maybe FileInfo)
 fileAFormOpt fs = AForm $ \(master, langs) menvs ints -> do

yesod-form/Yesod/Form/Functions.hs

@@ -243,8 +243,7 @@ generateFormPost
     -> m (xml, Enctype)
 generateFormPost form = first snd `liftM` postHelper form Nothing
 
-postEnv :: (MonadHandler m, MonadResource m)
-        => m (Maybe (Env, FileEnv))
+postEnv :: MonadHandler m => m (Maybe (Env, FileEnv))
 postEnv = do
     req <- getRequest
     if requestMethod (reqWaiRequest req) == "GET"
@@ -279,7 +278,7 @@ runFormGet form = do
 --
 -- Since 1.3.11
 generateFormGet'
-    :: (RenderMessage (HandlerSite m) FormMessage, MonadHandler m)
+    :: MonadHandler m
     => (Html -> MForm m (FormResult a, xml))
     -> m (xml, Enctype)
 generateFormGet' form = first snd `liftM` getHelper form Nothing

yesod-form/Yesod/Form/MassInput.hs

@@ -44,7 +44,7 @@ up i = do
 
 -- | Generate a form that accepts 0 or more values from the user, allowing the
 -- user to specify that a new row is necessary.
-inputList :: (m ~ HandlerT site IO, xml ~ WidgetT site IO (), RenderMessage site FormMessage)
+inputList :: (xml ~ WidgetT site IO (), RenderMessage site FormMessage)
           => Html
           -- ^ label for the form
           -> ([[FieldView site]] -> xml)
@@ -119,8 +119,7 @@ $newline never
     up 1
     return res
 
-fixme :: (xml ~ WidgetT site IO ())
-      => [Either xml (FormResult a, [FieldView site])]
+fixme :: [Either xml (FormResult a, [FieldView site])]
       -> (FormResult [a], [xml], [[FieldView site]])
 fixme eithers =
     (res, xmls, map snd rest)

yesod-static/Yesod/EmbeddedStatic.hs

@@ -59,7 +59,6 @@ import Network.Wai.Application.Static (staticApp)
 import System.IO.Unsafe (unsafePerformIO)
 import Yesod.Core
           ( HandlerT
-          , Yesod(..)
           , YesodSubDispatch(..)
           )
 import Yesod.Core.Types
@@ -82,7 +81,7 @@ import Yesod.EmbeddedStatic.Generators
 embeddedResourceR :: [T.Text] -> [(T.Text, T.Text)] -> Route EmbeddedStatic
 embeddedResourceR = EmbeddedResourceR
 
-instance Yesod master => YesodSubDispatch EmbeddedStatic (HandlerT master IO) where
+instance YesodSubDispatch EmbeddedStatic (HandlerT master IO) where
     yesodSubDispatch YesodSubRunnerEnv {..} req = resp
         where
             master = yreSite ysreParentEnv
@@ -176,8 +175,7 @@ mkEmbeddedStatic dev esName gen = do
 -- >     addStaticContent = embedStaticContent getStatic StaticR mini
 -- >         where mini = if development then Right else minifym
 -- >     ...
-embedStaticContent :: Yesod site
-                   => (site -> EmbeddedStatic)   -- ^ How to retrieve the embedded static subsite from your site
+embedStaticContent :: (site -> EmbeddedStatic)   -- ^ How to retrieve the embedded static subsite from your site
                    -> (Route EmbeddedStatic -> Route site) -- ^ how to convert an embedded static route
                    -> (BL.ByteString -> Either a BL.ByteString) -- ^ javascript minifier
                    -> AddStaticContent site

yesod-static/Yesod/EmbeddedStatic/Internal.hs

@@ -28,7 +28,6 @@ import Yesod.Core
           ( HandlerT
           , ParseRoute(..)
           , RenderRoute(..)
-          , Yesod(..)
           , getYesod
           , liftIO
           )
@@ -140,8 +139,7 @@ type AddStaticContent site = T.Text -> T.Text -> BL.ByteString
                           -> HandlerT site IO (Maybe (Either T.Text (Route site, [(T.Text, T.Text)])))
 
 -- | Helper for embedStaticContent and embedLicensedStaticContent.
-staticContentHelper :: Yesod site
-                    => (site -> EmbeddedStatic)
+staticContentHelper :: (site -> EmbeddedStatic)
                     -> (Route EmbeddedStatic -> Route site)
                     -> (BL.ByteString -> Either a BL.ByteString)
                     -> AddStaticContent site

yesod-test/Yesod/Test.hs

@@ -760,8 +760,7 @@ followRedirect = do
 -- > (Right (ResourceR resourceId)) <- getLocation
 --
 -- @since 1.5.4
-getLocation :: (Yesod site, ParseRoute site)
-            => YesodExample site (Either T.Text (Route site))
+getLocation :: ParseRoute site => YesodExample site (Either T.Text (Route site))
 getLocation = do
   mr <- getResponse
   case mr of
@@ -829,9 +828,7 @@ setUrl url' = do
 -- > import Data.Aeson
 -- > request $ do
 -- >   setRequestBody $ encode $ object ["age" .= (1 :: Integer)]
-setRequestBody :: (Yesod site)
-               => BSL8.ByteString
-               -> RequestBuilder site ()
+setRequestBody :: BSL8.ByteString -> RequestBuilder site ()
 setRequestBody body = ST.modify $ \rbd -> rbd { rbdPostData = BinaryPostData body }
 
 -- | Adds the given header to the request; see "Network.HTTP.Types.Header" for creating 'Header's.
@@ -859,8 +856,7 @@ addRequestHeader header = ST.modify $ \rbd -> rbd
 -- >   byLabel "First Name" "Felipe"
 -- >   setMethod "PUT"
 -- >   setUrl NameR
-request :: Yesod site
-        => RequestBuilder site ()
+request :: RequestBuilder site ()
         -> YesodExample site ()
 request reqBuilder = do
     YesodExampleData app site oldCookies mRes <- ST.get

yesod-websockets/Yesod/WebSockets.hs

@@ -130,10 +130,10 @@ webSocketsOptionsWith wsConnOpts buildAr inner = do
                     sink
 
 -- | Wrapper for capturing exceptions
-wrapWSE :: (MonadIO m, WS.WebSocketsData a) => (WS.Connection -> a -> IO ())-> a -> WebSocketsT m (Either SomeException ())
+wrapWSE :: MonadIO m => (WS.Connection -> a -> IO ())-> a -> WebSocketsT m (Either SomeException ())
 wrapWSE ws x = ReaderT $ liftIO . tryAny . flip ws x
 
-wrapWS :: (MonadIO m, WS.WebSocketsData a) => (WS.Connection -> a -> IO ()) -> a -> WebSocketsT m ()
+wrapWS :: MonadIO m => (WS.Connection -> a -> IO ()) -> a -> WebSocketsT m ()
 wrapWS ws x = ReaderT $ liftIO . flip ws x
 
 -- | Receive a piece of data from the client.

yesod/Yesod/Default/Main.hs

@@ -41,8 +41,7 @@ import Control.Concurrent.MVar (newEmptyMVar, putMVar, takeMVar)
 --   > main :: IO ()
 --   > main = defaultMain (fromArgs parseExtra) makeApplication
 --
-defaultMain :: (Show env, Read env)
-            => IO (AppConfig env extra)
+defaultMain :: IO (AppConfig env extra)
             -> (AppConfig env extra -> IO Application)
             -> IO ()
 defaultMain load getApp = do
@@ -60,8 +59,7 @@ type LogFunc = Loc -> LogSource -> LogLevel -> LogStr -> IO ()
 -- @Application@ to install Warp exception handlers.
 --
 -- Since 1.2.5
-defaultMainLog :: (Show env, Read env)
-               => IO (AppConfig env extra)
+defaultMainLog :: IO (AppConfig env extra)
                -> (AppConfig env extra -> IO (Application, LogFunc))
                -> IO ()
 defaultMainLog load getApp = do
@@ -113,8 +111,7 @@ defaultRunner f app = do
 -- | Run your development app using a custom environment type and loader
 --   function
 defaultDevelApp
-    :: (Show env, Read env)
-    => IO (AppConfig env extra) -- ^ A means to load your development @'AppConfig'@
+    :: IO (AppConfig env extra) -- ^ A means to load your development @'AppConfig'@
     -> (AppConfig env extra -> IO Application) -- ^ Get your @Application@
     -> IO (Int, Application)
 defaultDevelApp load getApp = do