From 0ed89c569f95d884fb8107a555f8a03672a0fffd Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <e.dolstra@tudelft.nl>
Date: Tue, 5 Feb 2008 13:38:07 +0000
Subject: [PATCH] * Fix the parsing of

    ''
      '${foo}'
    ''

  where the antiquote should work as expected, instead of giving the
  string "'${foo}'".
---
 src/libexpr/lexer.l | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/libexpr/lexer.l b/src/libexpr/lexer.l
index cf90f2939..b7c1d19f8 100644
--- a/src/libexpr/lexer.l
+++ b/src/libexpr/lexer.l
@@ -124,7 +124,7 @@ inherit     { return INHERIT; }
 <STRING>.   return yytext[0]; /* just in case: shouldn't be reached */
 
 \'\'(\ *\n)?     { BEGIN(IND_STRING); return IND_STRING_OPEN; }
-<IND_STRING>([^\$\']|\$[^\{\']|\'[^\'])+ {
+<IND_STRING>([^\$\']|\$[^\{\']|\'[^\'\$])+ {
                    yylval->t = makeIndStr(toATerm(yytext));
                    return IND_STR;
                  }
@@ -142,6 +142,10 @@ inherit     { return INHERIT; }
                  }
 <IND_STRING>\$\{ { BEGIN(INITIAL); return DOLLAR_CURLY; }
 <IND_STRING>\'\' { BEGIN(INITIAL); return IND_STRING_CLOSE; }
+<IND_STRING>\'   {
+                   yylval->t = makeIndStr(toATerm("'"));
+                   return IND_STR;
+                 }
 <IND_STRING>.    return yytext[0]; /* just in case: shouldn't be reached */
 
 {PATH}      { yylval->t = toATerm(yytext); return PATH; /* !!! alloc */ }