From 26d92bb8921ac4e022cdc88bde8fc7bc617f8766 Mon Sep 17 00:00:00 2001
From: Ondrej Zajicek <santiago@crfreenet.org>
Date: Wed, 23 Mar 2011 12:49:53 +0100
Subject: A hack to distinguish if..else from else: in case.

The old BIRD grammar needs two lookaheads to distinguish if..else from
else: in case, which caused the parser to fail on some combinations of
both expressions.

This patch replaces two tokens 'else' ':' by one token 'else:' to fix
that.
---
 conf/cf-lex.l    |  5 +++++
 conf/confbase.Y  |  2 +-
 doc/bird.sgml    |  2 +-
 filter/config.Y  |  4 ++--
 filter/test.conf | 13 +++++++------
 5 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index c6e9a0e..828dfd2 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -137,6 +137,11 @@ WHITE [ \t]
   return NUM;
 }
 
+else: {
+  /* Hack to distinguish if..else from else: in case */
+  return ELSECOL;
+}
+
 ({ALPHA}{ALNUM}*|[']({ALNUM}|[-])*[']) {
   if(*yytext == '\'') {
     yytext[yyleng-1] = 0;
diff --git a/conf/confbase.Y b/conf/confbase.Y
index ce844ba..68960c2 100644
--- a/conf/confbase.Y
+++ b/conf/confbase.Y
@@ -48,7 +48,7 @@ CF_DECLS
   struct timeformat *tf;
 }
 
-%token END CLI_MARKER INVALID_TOKEN
+%token END CLI_MARKER INVALID_TOKEN ELSECOL
 %token GEQ LEQ NEQ AND OR
 %token PO PC
 %token <i> NUM ENUM
diff --git a/doc/bird.sgml b/doc/bird.sgml
index 7b6e97a..b5bdb93 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -837,7 +837,7 @@ prefix and prefix (returning true if first prefix is more specific than second o
 <M>command_1</M>; <M>command_2</M>; <M>...</M> }</cf> instead of either command. The <cf>else</cf>
 clause may be omitted. If the <cf><m>boolean expression</m></cf> is true, <cf><m>command1</m></cf> is executed, otherwise <cf><m>command2</m></cf> is executed.
 
-<p>The <cf>case</cf> is similar to case from Pascal. Syntax is <cf>case <m/expr/ { else |
+<p>The <cf>case</cf> is similar to case from Pascal. Syntax is <cf>case <m/expr/ { else: |
 <m/num_or_prefix [ .. num_or_prefix]/: <m/statement/ ; [ ... ] }</cf>. The expression after
 <cf>case</cf> can be of any type which can be on the left side of the &tilde; operator and anything that could
 be a member of a set is allowed before <cf/:/. Multiple commands are allowed without <cf/{}/ grouping.
diff --git a/filter/config.Y b/filter/config.Y
index 8ff2046..b9aa67f 100644
--- a/filter/config.Y
+++ b/filter/config.Y
@@ -305,11 +305,11 @@ switch_body: /* EMPTY */ { $$ = NULL; }
      $$->data = $4;
      $$->left = $1;
    }
- | switch_body ELSE ':' cmds {
+ | switch_body ELSECOL cmds {
      $$ = f_new_tree(); 
      $$->from.type = T_VOID; 
      $$->to.type = T_VOID;
-     $$->data = $4;
+     $$->data = $3;
      $$->left = $1;
    }
  ;
diff --git a/filter/test.conf b/filter/test.conf
index 40fff19..6d7a708 100644
--- a/filter/test.conf
+++ b/filter/test.conf
@@ -27,14 +27,15 @@ int local1;
 int local2;
 int i;
 {
-	printn "Function callme called arguments ", arg1, " and ", arg2, ":" ;
+	printn "Function callme called arguments ", arg1, " and ", arg2, ": " ;
 	i = arg2;
 
 	case arg1 {
-	2: print "dva"; print "jeste jednou dva";
-	3 .. 5: print "tri az pet";
-	else: print "neco jineho";
-	}	
+	2: printn "dva, "; printn "jeste jednou dva";
+	3 .. 5: if arg2 < 3 then printn "tri az pet";
+	else: printn "neco jineho";
+	}
+	print;
 }
 
 function fifteen()
@@ -247,7 +248,7 @@ string s;
 	callme ( 2, 2 );
 	callme ( 2, 2 );
 	callme ( 3, 2 );
-	callme ( 4, 2 );
+	callme ( 4, 4 );
 	callme ( 7, 2 );
 
 	i = fifteen();
-- 
cgit v1.2.3