From: bjorn@bringert.net <unknown>
Date: Tue, 19 Sep 2006 01:06:06 +0000 (+0000)
Subject: First documentation on stand-alone instance deriving.
X-Git-Tag: 2006-10-05~11
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=9c5aa098ab000536caf3ac5f61d901d146d3e9d8

First documentation on stand-alone instance deriving.
---

diff --git a/docs/users_guide/glasgow_exts.xml b/docs/users_guide/glasgow_exts.xml
index f8ad5c1..b46bf30 100644
--- a/docs/users_guide/glasgow_exts.xml
+++ b/docs/users_guide/glasgow_exts.xml
@@ -3727,6 +3727,33 @@ the standard method is used or the one described here.)
 
 </sect2>
 
+<sect2 id="stand-alone-deriving">
+<title>Stand-alone deriving declarations</title>
+
+<para>
+GHC now allows stand-alone <literal>deriving</literal> declarations:
+</para>
+
+<programlisting>
+  data Foo = Bar Int | Baz String
+
+  deriving Eq for Foo
+</programlisting>
+
+<para>Deriving instances of multi-parameter type classes for newtypes is
+also allowed:</para>
+
+<programlisting>
+  newtype Foo a = MkFoo (State Int a)
+
+  deriving (MonadState Int) for Foo
+</programlisting>
+
+<para>
+</para>
+
+</sect2>
+
 <sect2 id="typing-binds">
 <title>Generalised typing of mutually recursive bindings</title>