[commit: ghc] wip/merge: template-haskell: Missing instances for Rational and (). (10f9097)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : wip/merge
Link       : http://ghc.haskell.org/trac/ghc/changeset/10f90970375a53971593fb4dcf52b0242a78eaf8/ghc

>---------------------------------------------------------------

commit 10f90970375a53971593fb4dcf52b0242a78eaf8
Author: Mathieu Boespflug <m at tweag.io>
Date:   Tue Nov 18 22:21:15 2014 -0600

    template-haskell: Missing instances for Rational and ().
    
    Test Plan: ./validate
    
    Reviewers: austin
    
    Reviewed By: austin
    
    Subscribers: thomie, carter
    
    Differential Revision: https://phabricator.haskell.org/D492


>---------------------------------------------------------------

10f90970375a53971593fb4dcf52b0242a78eaf8
 docs/users_guide/7.10.1-notes.xml                        |  5 +++++
 libraries/template-haskell/Language/Haskell/TH/Syntax.hs | 11 +++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/docs/users_guide/7.10.1-notes.xml b/docs/users_guide/7.10.1-notes.xml
index 2e509e1..0cf3f61 100644
--- a/docs/users_guide/7.10.1-notes.xml
+++ b/docs/users_guide/7.10.1-notes.xml
@@ -176,6 +176,11 @@
                  Various features unsupported in quotations were previously
                  silently ignored. These now cause errors.
                </para>
+
+                <para>
+                    <literal>Lift</literal> instances were added for
+                    <literal>()</literal> and <literal>Ratio</literal>.
+               </para>
            </listitem>
        </itemizedlist>
     </sect3>
diff --git a/libraries/template-haskell/Language/Haskell/TH/Syntax.hs b/libraries/template-haskell/Language/Haskell/TH/Syntax.hs
index 48199a4..9813095 100644
--- a/libraries/template-haskell/Language/Haskell/TH/Syntax.hs
+++ b/libraries/template-haskell/Language/Haskell/TH/Syntax.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE CPP, DeriveDataTypeable, PolymorphicComponents,
-             RoleAnnotations, DeriveGeneric #-}
+             RoleAnnotations, DeriveGeneric, TypeSynonymInstances,
+             FlexibleInstances #-}
 
 -----------------------------------------------------------------------------
 -- |
@@ -454,7 +455,10 @@ instance Lift Integer where
   lift x = return (LitE (IntegerL x))
 
 instance Lift Int where
-  lift x= return (LitE (IntegerL (fromIntegral x)))
+  lift x = return (LitE (IntegerL (fromIntegral x)))
+
+instance Lift Rational where
+  lift x = return (LitE (RationalL x))
 
 instance Lift Char where
   lift x = return (LitE (CharL x))
@@ -478,6 +482,9 @@ liftString :: String -> Q Exp
 -- Used in TcExpr to short-circuit the lifting for strings
 liftString s = return (LitE (StringL s))
 
+instance Lift () where
+  lift () = return (ConE (tupleDataName 0))
+
 instance (Lift a, Lift b) => Lift (a, b) where
   lift (a, b)
     = liftM TupE $ sequence [lift a, lift b]