From b8d0c391b1df3556ce3d85c05ed391057261613b Mon Sep 17 00:00:00 2001
From: simonmar <unknown>
Date: Tue, 16 Oct 2001 10:50:11 +0000
Subject: [PATCH] [project @ 2001-10-16 10:50:11 by simonmar] mention that
 identifiers beginning with a double underscore are to be
 avoided in -fglasgow-exts mode.

---
 ghc/docs/users_guide/vs_haskell.sgml |   10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/ghc/docs/users_guide/vs_haskell.sgml b/ghc/docs/users_guide/vs_haskell.sgml
index e7e922a..7e0cc47 100644
--- a/ghc/docs/users_guide/vs_haskell.sgml
+++ b/ghc/docs/users_guide/vs_haskell.sgml
@@ -36,6 +36,16 @@
 	  single qualified operator rather than the two lexemes
 	  <literal>M</literal> and <literal>.\</literal>.</para>
 	</listitem>
+
+	<listitem>
+	  <para>When <option>-fglasgow-exts</option> is on, GHC
+	  reserves several keywords beginning with two underscores.
+	  This is due to the fact that GHC uses the same lexical
+	  analyser for interface file parsing as it does for source
+	  file parsing, and these keywords are used in interface
+	  files.  Do not use any identifiers beginning with a double
+	  underscore in <option>-fglasgow-exts</option> mode.</para>
+	</listitem>
       </itemizedlist>
     </sect3>
       
-- 
1.7.10.4