{- | parses an entity type (subject, predicate or object) followed by a
comma separated list of IRIs -}
rdfSymbItems :: GenParser Char st SymbItems
rdfSymbItems = do
    ext <- optionMaybe rdfEntityType
    iris <- rdfSymbs
    return $ SymbItems ext iris

-- | parse a comma separated list of uris
rdfSymbItems :: GenParser Char st SymbItems
rdfSymbItems = do
    ext <- optionMaybe rdfEntityType
    iris <- rdfSymbs
    return $ SymbItems ext iris

-- | parse a comma separated list of uris
rdfSymbItems = do
    ext <- optionMaybe rdfEntityType
    iris <- rdfSymbs
    return $ SymbItems ext iris

-- | parse a comma separated list of uris