From 00635452b96eaa7cdef8239b5c02c59fd9b9e593 Mon Sep 17 00:00:00 2001
From: Andrew Martin <amartin@layer3com.com>
Date: Tue, 21 Jul 2015 11:07:52 -0400
Subject: [PATCH 1/4] Add IsString instance for WidgetT site m ()

---
 yesod-core/Yesod/Core/Types.hs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/yesod-core/Yesod/Core/Types.hs b/yesod-core/Yesod/Core/Types.hs
index 5fa5c3d3..f41bcbd0 100644
--- a/yesod-core/Yesod/Core/Types.hs
+++ b/yesod-core/Yesod/Core/Types.hs
@@ -48,7 +48,7 @@ import qualified Network.Wai.Parse                  as NWP
 import           System.Log.FastLogger              (LogStr, LoggerSet, toLogStr, pushLogStr)
 import qualified System.Random.MWC                  as MWC
 import           Network.Wai.Logger                 (DateCacheGetter)
-import           Text.Blaze.Html                    (Html)
+import           Text.Blaze.Html                    (Html, toHtml)
 import           Text.Hamlet                        (HtmlUrl)
 import           Text.Julius                        (JavascriptUrl)
 import           Web.Cookie                         (SetCookie)
@@ -250,6 +250,10 @@ instance (a ~ (), Monad m) => Monoid (WidgetT site m a) where
     mempty = return ()
     mappend x y = x >> y
 instance (a ~ (), Monad m) => Semigroup (WidgetT site m a)
+instance Monad m => IsString (WidgetT site m ()) where
+    fromString = toWidget . toHtml . T.pack
+      where toWidget x = WidgetT $ const $ return $ ((), GWData (Body (const x)) 
+                         mempty mempty mempty mempty mempty mempty)
 
 type RY master = Route master -> [(Text, Text)] -> Text
 

From 4e354c9e07fb099707d03e3cd48e1d4171996599 Mon Sep 17 00:00:00 2001
From: Andrew Martin <amartin@layer3com.com>
Date: Tue, 21 Jul 2015 11:37:09 -0400
Subject: [PATCH 2/4] Improve type inference for WidgetT IsString instance

---
 yesod-core/Yesod/Core/Types.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/yesod-core/Yesod/Core/Types.hs b/yesod-core/Yesod/Core/Types.hs
index f41bcbd0..d96f10bf 100644
--- a/yesod-core/Yesod/Core/Types.hs
+++ b/yesod-core/Yesod/Core/Types.hs
@@ -250,7 +250,7 @@ instance (a ~ (), Monad m) => Monoid (WidgetT site m a) where
     mempty = return ()
     mappend x y = x >> y
 instance (a ~ (), Monad m) => Semigroup (WidgetT site m a)
-instance Monad m => IsString (WidgetT site m ()) where
+instance (Monad m, a ~ ()) => IsString (WidgetT site m a) where
     fromString = toWidget . toHtml . T.pack
       where toWidget x = WidgetT $ const $ return $ ((), GWData (Body (const x)) 
                          mempty mempty mempty mempty mempty mempty)

From 66ed3148664cc045dad8c446f4384044d89339e5 Mon Sep 17 00:00:00 2001
From: Christopher Reichert <creichert07@gmail.com>
Date: Tue, 21 Jul 2015 11:50:21 -0500
Subject: [PATCH 3/4] Document IsString instance for WidgetT.

---
 yesod-core/Yesod/Core/Types.hs | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/yesod-core/Yesod/Core/Types.hs b/yesod-core/Yesod/Core/Types.hs
index d96f10bf..331238c0 100644
--- a/yesod-core/Yesod/Core/Types.hs
+++ b/yesod-core/Yesod/Core/Types.hs
@@ -250,9 +250,16 @@ instance (a ~ (), Monad m) => Monoid (WidgetT site m a) where
     mempty = return ()
     mappend x y = x >> y
 instance (a ~ (), Monad m) => Semigroup (WidgetT site m a)
+
+-- | Any type with an 'IsString' instance can be trivially
+-- promoted to a widget.
+--
+-- For example, in a yesod-scaffold site you could use:
+--
+-- @getHomeR = do defaultLayout "Widget text"@
 instance (Monad m, a ~ ()) => IsString (WidgetT site m a) where
     fromString = toWidget . toHtml . T.pack
-      where toWidget x = WidgetT $ const $ return $ ((), GWData (Body (const x)) 
+      where toWidget x = WidgetT $ const $ return $ ((), GWData (Body (const x))
                          mempty mempty mempty mempty mempty mempty)
 
 type RY master = Route master -> [(Text, Text)] -> Text

From a5a627db58ac41e37067f047889ca3b803285f7c Mon Sep 17 00:00:00 2001
From: Christopher Reichert <creichert07@gmail.com>
Date: Tue, 21 Jul 2015 13:19:00 -0500
Subject: [PATCH 4/4] Clarify IsString instance for Widget only works with
 Strings.

---
 yesod-core/Yesod/Core/Types.hs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/yesod-core/Yesod/Core/Types.hs b/yesod-core/Yesod/Core/Types.hs
index 331238c0..2c39f90d 100644
--- a/yesod-core/Yesod/Core/Types.hs
+++ b/yesod-core/Yesod/Core/Types.hs
@@ -251,8 +251,7 @@ instance (a ~ (), Monad m) => Monoid (WidgetT site m a) where
     mappend x y = x >> y
 instance (a ~ (), Monad m) => Semigroup (WidgetT site m a)
 
--- | Any type with an 'IsString' instance can be trivially
--- promoted to a widget.
+-- | A 'String' can be trivially promoted to a widget.
 --
 -- For example, in a yesod-scaffold site you could use:
 --