remove the transfer modules. We don't need anything special, a transfer module is module without concrete syntax

src/GF/Grammar/Binary.hs

@@ -37,7 +37,6 @@ instance (Ord i, Binary i, Binary a) => Binary (ModInfo i a) where
 
 instance (Binary i) => Binary (ModuleType i) where
   put MTAbstract       = putWord8 0
-  put (MTTransfer i j) = putWord8 1 >> put (i,j)
   put MTResource       = putWord8 2
   put (MTConcrete i)   = putWord8 3 >> put i
   put MTInterface      = putWord8 4
@@ -45,7 +44,6 @@ instance (Binary i) => Binary (ModuleType i) where
   get = do tag <- getWord8
            case tag of
              0 -> return MTAbstract
-             1 -> get >>= \(i,j) -> return (MTTransfer i j)
              2 -> return MTResource
              3 -> get >>= return . MTConcrete
              4 -> return MTInterface

src/GF/Grammar/Parser.y

@@ -91,7 +91,6 @@ import GF.Compile.Update (buildAnyTree)
  'resource'   { T_resource  }
  'strs'       { T_strs      }
  'table'      { T_table     }
- 'transfer'   { T_transfer  }
  'variants'   { T_variants  }
  'where'      { T_where     }
  'with'       { T_with      }
@@ -143,7 +142,6 @@ ModType
   | 'interface' Ident                    { (MTInterface,     $2) }
   | 'concrete'  Ident 'of' Ident         { (MTConcrete $4,   $2) }
   | 'instance'  Ident 'of' Ident         { (MTInstance $4,   $2) }
-  | 'transfer'  Ident ':' Open '->' Open { (MTTransfer $4 $6,$2) }
 
 ModHeaderBody :: { ( [(Ident,MInclude Ident)]
                    , Maybe (Ident,MInclude Ident,[(Ident,Ident)])
@@ -701,11 +699,6 @@ checkInfoType (MTInstance _)   (id,pos,info) =
     ResValue _   -> return ()
     ResOper  _ _ -> return ()
     _            -> failLoc (fst pos) "illegal definition in instance module" 
-checkInfoType (MTTransfer _ _) (id,pos,info) =
-  case info of
-    AbsCat _ _   -> return ()
-    AbsFun _ _ _ -> return ()
-    _            -> failLoc (fst pos) "illegal definition in transfer module" 
 
 
 mkAlts cs = case cs of

src/GF/Grammar/Printer.hs

@@ -58,7 +58,6 @@ ppModule q (mn, ModInfo mtype mstat opts exts with opens _ jments _) =
       modTypeDoc =
         case mtype of
           MTAbstract         -> text "abstract"  <+> ppIdent mn
-          MTTransfer src dst -> text "transfer"  <+> ppIdent mn <+> colon <+> ppOpenSpec src <+> text "->" <+> ppOpenSpec dst
           MTResource         -> text "resource"  <+> ppIdent mn
           MTConcrete abs     -> text "concrete"  <+> ppIdent mn <+> text "of" <+> ppIdent abs
           MTInterface        -> text "interface" <+> ppIdent mn