the symbol for nonExist in the GF runtime should be the last. this simplifies the binary search in the C runtime

src/runtime/c/pgf/data.h

@@ -178,8 +178,8 @@ typedef enum {
 	PGF_SYMBOL_VAR,
 	PGF_SYMBOL_KS,
 	PGF_SYMBOL_KP,
-	PGF_SYMBOL_NE,
-	PGF_SYMBOL_BIND
+	PGF_SYMBOL_BIND,
+	PGF_SYMBOL_NE
 } PgfSymbolTag;
 
 typedef struct {

src/runtime/haskell/PGF/Data.hs

@@ -59,9 +59,9 @@ data Symbol
   | SymLit {-# UNPACK #-} !Int {-# UNPACK #-} !LIndex
   | SymVar {-# UNPACK #-} !Int {-# UNPACK #-} !Int
   | SymKS Token
-  | SymNE                           -- non exist
-  | SymBIND                         -- the special BIND token
   | SymKP [Symbol] [([Symbol],[String])]
+  | SymBIND                         -- the special BIND token
+  | SymNE                           -- non exist (this should be last constructor to simplify the binary search in the runtime)
   deriving (Eq,Ord,Show)
 data Production
   = PApply  {-# UNPACK #-} !FunId [PArg]