update documentation for PostfixOperators

diff --git a/docs/users_guide/glasgow_exts.xml b/docs/users_guide/glasgow_exts.xml
index 784f569..2169bba 100644 (file)
--- a/docs/users_guide/glasgow_exts.xml
+++ b/docs/users_guide/glasgow_exts.xml
@@ -1176,8 +1176,9 @@ fromInteger :: Integer -> Bool -> Bool
 <title>Postfix operators</title>
 
 <para>
-GHC allows a small extension to the syntax of left operator sections, which
-allows you to define postfix operators.  The extension is this:  the left section
+  The <option>-XPostfixOperators</option> flag enables a small
+extension to the syntax of left operator sections, which allows you to
+define postfix operators.  The extension is this: the left section
 <programlisting>
   (e !)
 </programlisting>
@@ -1194,10 +1195,6 @@ That is, the operator must be a function of two arguments.  GHC allows it to
 take only one argument, and that in turn allows you to write the function
 postfix.
 </para>
-<para>Since this extension goes beyond Haskell 98, it should really be enabled
-by a flag; but in fact it is enabled all the time.  (No Haskell 98 programs
-change their behaviour, of course.)
-</para>
 <para>The extension does not extend to the left-hand side of function
 definitions; you must define such a function in prefix form.</para>