regular expression patterns

src/GF/Source/AbsGF.hs

@@ -224,6 +224,7 @@ data Patt =
  | PSeq Patt Patt
  | PRep Patt
  | PAs Ident Patt
+ | PNeg Patt
   deriving (Eq,Ord,Show)
 
 data PattAss =

src/GF/Source/GF.cf

@@ -225,6 +225,7 @@ PDisj.  Patt   ::= Patt "|" Patt1 ;
 PSeq.   Patt   ::= Patt "+" Patt1 ;
 PRep.   Patt1  ::= Patt2 "*" ;
 PAs.    Patt1  ::= Ident "@" Patt2 ;
+PNeg.   Patt1  ::= "-" Patt2 ;
 
 coercions Patt 2 ;
 

src/GF/Source/GrammarToSource.hs

@@ -202,6 +202,7 @@ trp p = case p of
     PAlt p q -> P.PDisj (trp p) (trp q)
     PSeq p q -> P.PSeq (trp p) (trp q)
     PRep p   -> P.PRep (trp p)
+    PNeg p   -> P.PNeg (trp p)
 
 
 trAssign (lab, (mty, t)) = maybe (P.LDDef x t') (\ty -> P.LDFull x (trt ty) t') mty

src/GF/Source/ParGF.y

@@ -456,6 +456,7 @@ Patt1 : Ident ListPatt { PC $1 $2 }
   | Ident '.' Ident ListPatt { PQC $1 $3 $4 }
   | Patt2 '*' { PRep $1 }
   | Ident '@' Patt2 { PAs $1 $3 }
+  | '-' Patt2 { PNeg $2 }
   | Patt2 { $1 }
 
 

src/GF/Source/PrintGF.hs

@@ -402,6 +402,7 @@ instance Print Patt where
    PSeq patt0 patt -> prPrec i 0 (concatD [prt 0 patt0 , doc (showString "+") , prt 1 patt])
    PRep patt -> prPrec i 1 (concatD [prt 2 patt , doc (showString "*")])
    PAs id patt -> prPrec i 1 (concatD [prt 0 id , doc (showString "@") , prt 2 patt])
+   PNeg patt -> prPrec i 1 (concatD [doc (showString "-") , prt 2 patt])
 
   prtList es = case es of
    [x] -> (concatD [prt 2 x])

src/GF/Source/SourceToGrammar.hs

@@ -559,7 +559,8 @@ transPatt x = case x of
   PDisj p1 p2 -> liftM2 G.PAlt (transPatt p1) (transPatt p2)
   PSeq p1 p2  -> liftM2 G.PSeq (transPatt p1) (transPatt p2)
   PRep p      -> liftM  G.PRep (transPatt p)
-  PAs x p     -> liftM2 G.PAs (transIdent x) (transPatt p)
+  PNeg p      -> liftM  G.PNeg (transPatt p)
+  PAs x p     -> liftM2 G.PAs  (transIdent x) (transPatt p)