[ BNF.cf ] Fixed #215: allow extra semicolons between LBNF defs.

.gitignore

@@ -32,3 +32,4 @@ cabal.sandbox.config
 /source/src/LexBNF.info
 /source/src/ParBNF.hs
 /source/src/ParBNF.info
+/source/src/TestBNF

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] ;

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 }

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"