[project @ 2001-04-27 08:50:59 by simonmar]

add a note about requiring 'main' to be defined in module 'Main'.

diff --git a/ghc/docs/users_guide/ghci.sgml b/ghc/docs/users_guide/ghci.sgml
index 55e09bb..3f8783f 100644 (file)
--- a/ghc/docs/users_guide/ghci.sgml
+++ b/ghc/docs/users_guide/ghci.sgml
@@ -927,6 +927,21 @@ Prelude> :set -fno-glasgow-exts
     
     <variablelist>
       <varlistentry>
+       <term>GHCi complains about <function>main</function> not being
+       in scope when I load a module.</term>
+       <indexterm><primary><function>main</function></primary><secondary>with GHCi</secondary>
+       </indexterm>
+       <listitem>
+         <para>You probably omitted the <literal>module</literal>
+         declaration at the top of the module, which causes the
+         module name to default to <literal>Main</literal>.  In
+         Haskell, the <literal>Main</literal> module must define a
+         function called <function>main</function>.  Admittedly this
+         doesn't make a great deal of sense for an interpreter, but
+         the rule was kept for compatibility with GHC.</para>
+       </listitem>
+
+      <varlistentry>
        <term><literal>System.exit</literal> causes GHCi to exit!</term>
        <indexterm><primary><literal>System.exit</literal></primary><secondary>in
        GHCi</secondary></indexterm>