From 6cb6e929f1e0eebf11368aa89509065f1db77a7e Mon Sep 17 00:00:00 2001
From: Andreas Abel <andreas.abel@ifi.lmu.de>
Date: Mon, 1 Jan 2018 23:47:44 +0100
Subject: [PATCH] [ BNF.cf ] Fixed #215: allow extra semicolons between LBNF
 defs.

---
 .gitignore                        |  1 +
 source/src/BNF.cf                 | 15 +++++++++++++--
 source/src/ParBNF.y               |  2 ++
 testing/src/ParameterizedTests.hs |  2 +-
 4 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/.gitignore b/.gitignore
index 81aea3f9..e399a3d7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -32,3 +32,4 @@ cabal.sandbox.config
 /source/src/LexBNF.info
 /source/src/ParBNF.hs
 /source/src/ParBNF.info
+/source/src/TestBNF
diff --git a/source/src/BNF.cf b/source/src/BNF.cf
index 51088e71..57a8cf46 100644
--- a/source/src/BNF.cf
+++ b/source/src/BNF.cf
@@ -25,14 +25,25 @@ DefAll.   LDef ::= Def ;
 DefSome.  LDef ::= [Ident] ":" Def ;
 LDefView. LDef ::= "views" [Ident] ;
 
-separator LDef ";" ;
+-- separator LDef ";" ;
+[].       [LDef] ::= ;
+(:[]).    [LDef] ::= LDef ;
+(:).      [LDef] ::= LDef ";" [LDef] ;
+-- extra semicolons allowed
+_.        [LDef] ::= ";" [LDef] ;
+
 separator nonempty Ident "," ;
 
 -- A Grammar is a sequence of definitions
 
 Grammar . Grammar ::= [Def] ;
 
-separator Def ";" ;
+-- separator Def ";" ;  -- Note: this still permits a final semicolon.
+[].       [Def] ::= ;
+(:[]).    [Def] ::= Def ;
+(:).      [Def] ::= Def ";" [Def] ;
+-- extra semicolons allowed
+_.        [Def] ::= ";" [Def] ;
 
 -- The rules of the grammar
 Rule .    Def ::= Label "." Cat "::=" [Item] ;
diff --git a/source/src/ParBNF.y b/source/src/ParBNF.y
index 72209f52..cc563074 100644
--- a/source/src/ParBNF.y
+++ b/source/src/ParBNF.y
@@ -111,6 +111,7 @@ ListLDef :: { [LDef] }
 ListLDef : {- empty -} { [] }
          | LDef { (:[]) $1 }
          | LDef ';' ListLDef { (:) $1 $3 }
+         | ';' ListLDef { $2 }
 ListIdent :: { [Ident] }
 ListIdent : Ident { (:[]) $1 } | Ident ',' ListIdent { (:) $1 $3 }
 Grammar :: { Grammar }
@@ -119,6 +120,7 @@ ListDef :: { [Def] }
 ListDef : {- empty -} { [] }
         | Def { (:[]) $1 }
         | Def ';' ListDef { (:) $1 $3 }
+        | ';' ListDef { $2 }
 Def :: { Def }
 Def : Label '.' Cat '::=' ListItem { AbsBNF.Rule $1 $3 (reverse $5) }
     | 'comment' String { AbsBNF.Comment $2 }
diff --git a/testing/src/ParameterizedTests.hs b/testing/src/ParameterizedTests.hs
index dbee7f65..1eeb3885 100644
--- a/testing/src/ParameterizedTests.hs
+++ b/testing/src/ParameterizedTests.hs
@@ -49,7 +49,7 @@ exitCodeTest params =
     makeShellyTest "Test program exits with code 1 on failure" $
         withTmpDir $ \tmp -> do
             cd tmp
-            writefile "Abra.cf" "F. C ::= \"abracadabra\";"
+            writefile "Abra.cf" ";; F. C ::= \"abracadabra\" ;"  -- leading semicolon for #215
             tpBnfc params "Abra.cf"
             tpBuild params
             setStdin "bad"