[project @ 2005-06-13 14:36:01 by simonmar]

- Fix up documentation for about new automatic printing semantics
- Document :tags

diff --git a/ghc/docs/users_guide/ghci.xml b/ghc/docs/users_guide/ghci.xml
index a0210ea..cac0e11 100644 (file)
--- a/ghc/docs/users_guide/ghci.xml
+++ b/ghc/docs/users_guide/ghci.xml
@@ -63,6 +63,7 @@ Prelude>
    :show modules              show the currently loaded modules
    :show bindings             show the current bindings made at the prompt
 
+   :tags -e|-c                create tags file for Vi (-c) or Emacs (-e)
    :type <expr>               show the type of <expr>
    :kind <type>               show the kind of <type>
    :undef <cmd>               undefine user-defined command :<cmd>
@@ -428,16 +429,30 @@ Prelude>
       <literal>x</literal> in future statements, for example to print
       it as we did above.</para>
 
+      <para>GHCi will print the result of a statement if and only if: 
+       <itemizedlist>
+         <listitem>
+           <para>The statement is not a binding, or it is a monadic binding 
+             (<literal>p &lt;- e</literal>) that binds exactly one
+             variable.</para>
+         </listitem>
+         <listitem>
+           <para>The variable's type is not polymorphic, is not
+             <literal>()</literal>, and is an instance of
+             <literal>Show</literal></para>
+         </listitem>
+       </itemizedlist>
+      </para>
+
       <para>Of course, you can also bind normal non-IO expressions
       using the <literal>let</literal>-statement:</para>
 <screen>
 Prelude> let x = 42
-42
-Prelude> print x
+Prelude> x
 42
 Prelude>
 </screen>
-      <para>An important difference between the two types of binding
+      <para>Another important difference between the two types of binding
       is that the monadic bind (<literal>p &lt;- e</literal>) is
       <emphasis>strict</emphasis> (it evaluates <literal>e</literal>),
       whereas with the <literal>let</literal> form, the expression
@@ -448,22 +463,16 @@ Prelude> print x
 *** Exception: help!
 Prelude>
 </screen>
-<para>GHCi will print the result of a 
-<literal>x&lt;-e</literal> statement if and only if:
-<itemizedlist>
-<listitem><para>The statement binds exactly one variable</para></listitem>
-<listitem><para>The variable's type is not polymorphic, is not
-<literal>()</literal>,
-and is an instance of <literal>Show</literal>
-</para></listitem>
-</itemizedlist>
+
+      <para>Note that <literal>let</literal> bindings do not automatically
+       print the value bound, unlike monadic bindings.</para>
+
       <para>Any exceptions raised during the evaluation or execution
       of the statement are caught and printed by the GHCi command line
       interface (for more information on exceptions, see the module
       <literal>Control.Exception</literal> in the libraries
       documentation).</para>
 
-
       <para>Every new binding shadows any existing bindings of the
       same name, including entities that are in scope in the current
       module context.</para>
@@ -493,7 +502,7 @@ Prelude> let (x:xs) = [1..]
 x :: Integer
 xs :: [Integer]
 </screen>
-</para>
+
     </sect2>
 
     <sect2 id="ghci-scope">
@@ -1129,6 +1138,23 @@ Prelude> :. cmds.ghci
 
       <varlistentry>
        <term>
+         <literal>:tags -c|-e</literal>
+         <indexterm><primary><literal>:tags</literal></primary>
+         </indexterm>
+       </term>
+       <listitem>
+         <para>Generates a &ldquo;tags&rdquo; file for either Vi-style editors
+           (<literal>-c</literal>) or Emacs-style editors
+           (<literal>-e</literal>).  The file generated will be called
+           <filename>tags</filename> or <filename>TAGS</filename>
+           respectively.</para>
+
+          <para>See also <xref linkend="hasktags" />.</para>
+       </listitem>
+      </varlistentry>
+
+      <varlistentry>
+       <term>
          <literal>:type</literal> <replaceable>expression</replaceable>
          <indexterm><primary><literal>:type</literal></primary></indexterm>
         </term>