diff --git a/docs/users_guide/7.4.1-notes.xml b/docs/users_guide/7.4.1-notes.xml index 3bbe89c56e954aa3e5561174c9ed2cc987bdb645..f90847cda593dc08616c2782e7e8ef10251f8faa 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>