Changes for the new IO library, mainly base-package modules moving around

[ghc-hetmet.git] / docs / users_guide / using.xml

diff --git a/docs/users_guide/using.xml b/docs/users_guide/using.xml
index f769d28..478a6bc 100644 (file)
--- a/docs/users_guide/using.xml
+++ b/docs/users_guide/using.xml
@@ -120,7 +120,7 @@ module X where
        <listitem>
          <para>Most non-mode flags fall into this category.  A dynamic flag
            may be used on the command line, in a
-           <literal>GHC_OPTIONS</literal> pragma in a source file, or set
+           <literal>OPTIONS_GHC</literal> pragma in a source file, or set
            using <literal>:set</literal> in GHCi.</para>
        </listitem>
       </varlistentry>
@@ -844,7 +844,8 @@ ghc -c Foo.hs</screen>
     <option>-fwarn-deprecated-flags</option>,
     <option>-fwarn-duplicate-exports</option>,
     <option>-fwarn-missing-fields</option>,
-    <option>-fwarn-missing-methods</option>, and
+    <option>-fwarn-missing-methods</option>,
+    <option>-fwarn-lazy-unlifted-bindings</option>, and
     <option>-fwarn-dodgy-foreign-imports</option>.  The following
     flags are
     simple ways to select standard &ldquo;packages&rdquo; of warnings:
@@ -992,7 +993,7 @@ foreign import "&amp;f" f :: FunPtr t
        <listitem>
          <indexterm><primary><option>-fwarn-dodgy-imports</option></primary>
          </indexterm>
-         <para>Causes a warning to be emitted when a a datatype
+         <para>Causes a warning to be emitted when a datatype
       <literal>T</literal> is imported
       with all constructors, i.e. <literal>T(..)</literal>, but has been
       exported abstractly, i.e. <literal>T</literal>.</para>
@@ -1000,6 +1001,20 @@ foreign import "&amp;f" f :: FunPtr t
       </varlistentry>
 
       <varlistentry>
+       <term><option>-fwarn-lazy-unlifted-bindings</option>:</term>
+       <listitem>
+         <indexterm><primary><option>-fwarn-lazy-unlifted-bindings</option></primary>
+         </indexterm>
+         <para>Causes a warning to be emitted when an unlifted type
+      is bound in a way that looks lazy, e.g.
+      <literal>where (I# x) = ...</literal>. Use
+      <literal>where !(I# x) = ...</literal> instead. This will be an
+      error, rather than a warning, in GHC 6.14.
+      </para>
+       </listitem>
+      </varlistentry>
+
+      <varlistentry>
        <term><option>-fwarn-duplicate-exports</option>:</term>
        <listitem>
          <indexterm><primary><option>-fwarn-duplicate-exports</option></primary></indexterm>
@@ -1175,6 +1190,11 @@ f foo = foo { x = 6 }
           typographical errors that turn into hard-to-find bugs, e.g.,
           in the inadvertent capture of what would be a recursive call in
           <literal>f = ... let f = id in ... f ...</literal>.</para>
+          <para>The warning is suppressed for names beginning with an underscore.  For example
+          <programlisting>
+             f x = do { _ignore &lt;- this; _ignore &lt;- that; return (the other) }
+          </programlisting>
+         </para>
        </listitem>
       </varlistentry>