From 0c8acc3997f5c0b841d61f0d32597cc2f2bf66b1 Mon Sep 17 00:00:00 2001
From: Ian Lynagh <igloo@earth.li>
Date: Sat, 14 Jan 2012 14:59:40 +0000
Subject: [PATCH] Improve the documentation of the Num superclass changes in
the release notes
---
docs/users_guide/7.4.1-notes.xml | 56 ++++++++++++++++++++++++++++++++
1 file changed, 56 insertions(+)
diff --git a/docs/users_guide/7.4.1-notes.xml b/docs/users_guide/7.4.1-notes.xml
index 3bbe89c56e95..f90847cda593 100644
--- a/docs/users_guide/7.4.1-notes.xml
+++ b/docs/users_guide/7.4.1-notes.xml
@@ -16,6 +16,40 @@
</para>
<itemizedlist>
+ <listitem>
+ <para>
+ The <literal>Num</literal> class no longer has
+ <literal>Eq</literal> or <literal>Show</literal>
+ superclasses. A number of other classes and
+ functions have therefore gained explicit
+ <literal>Eq</literal> or <literal>Show</literal>
+ constraints, rather than relying on a
+ <literal>Num</literal> constraint to provide them.
+ </para>
+
+ <para>
+ You can make code that works with both
+ Haskell98/Haskell2010 and GHC by:
+ <itemizedlist>
+ <listitem>
+ <para>
+ Whenever you make a <literal>Num</literal> instance
+ of a type, also make <literal>Show</literal> and
+ <literal>Eq</literal> instances, and
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Whenever you give a function, instance or class a
+ <literal>Num t</literal> constraint, also give it
+ <literal>Show t</literal> and
+ <literal>Eq t</literal> constraints.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </para>
+ </listitem>
+
<listitem>
<para>
There is a new feature Safe Haskell
@@ -1079,6 +1113,28 @@ Subject: [PATCH 0695/1074] Add an RTS eventlog tracing class for user messages
constraints, rather than relying on a
<literal>Num</literal> constraint to provide them.
</para>
+
+ <para>
+ You can make code that works with both
+ Haskell98/Haskell2010 and GHC by:
+ <itemizedlist>
+ <listitem>
+ <para>
+ Whenever you make a <literal>Num</literal> instance
+ of a type, also make <literal>Show</literal> and
+ <literal>Eq</literal> instances, and
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Whenever you give a function, instance or class a
+ <literal>Num t</literal> constraint, also give it
+ <literal>Show t</literal> and
+ <literal>Eq t</literal> constraints.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </para>
</listitem>
<listitem>
--
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