{-
scontext -> class | "(" class1 "," ... "," classn ")"    (n>=0)
simpleclass -> tycls tyvar
         (other case in Haskell report at 'class' is not supported in Helium
          because we do not have type variable application)
-}

scontext :: HParser ContextItems
scontext = 
    do { c <- simpleclass; return [c] }
    <|>
    parens (commas simpleclass)
scontext :: HParser ContextItems
scontext = 
    do { c <- simpleclass; return [c] }
    <|>
    parens (commas simpleclass)
scontext = 
    do { c <- simpleclass; return [c] }
    <|>
    parens (commas simpleclass)