uriPair :: GenParser Char st (IRI, Maybe IRI)
uriPair = uriP >>= \ u -> do
    pToken $ toKey mapsTo
    u2 <- uriP
    return (u, Just u2)
  <|> return (u, Nothing)
uriPair :: GenParser Char st (IRI, Maybe IRI)
uriPair = uriP >>= \ u -> do
    pToken $ toKey mapsTo
    u2 <- uriP
    return (u, Just u2)
  <|> return (u, Nothing)
uriPair = uriP >>= \ u -> do
    pToken $ toKey mapsTo
    u2 <- uriP
    return (u, Just u2)
  <|> return (u, Nothing)