primT :: ReadP Term
primT = do
  char primTag
  name <- munch1 isVarRestChar
  case Map.lookup name primsByName of
    Just p  -> return $ PrimT p
    Nothing -> pfail
primT :: ReadP Term
primT = do
  char primTag
  name <- munch1 isVarRestChar
  case Map.lookup name primsByName of
    Just p  -> return $ PrimT p
    Nothing -> pfail
primT = do
  char primTag
  name <- munch1 isVarRestChar
  case Map.lookup name primsByName of
    Just p  -> return $ PrimT p
    Nothing -> pfail