adamc@846: fun foldlPartial [a] [b] [c] f =
adamc@846:     let
adamc@846:         fun foldlPartial' acc ls1 ls2 =
adamc@846:             case (ls1, ls2) of
adamc@846:                 ([], []) => Some acc
adamc@846:               | (x1 :: ls1, x2 :: ls2) =>
adamc@846:                 (case f x1 x2 acc of
adamc@846:                      None => None
adamc@846:                    | Some acc' => foldlPartial' acc' ls1 ls2)
adamc@846:               | _ => None
adamc@846:     in
adamc@846:         foldlPartial'
adamc@846:     end
adamc@846: 
adamc@826: fun mapX [a] [b] [ctx ::: {Unit}] f =
adamc@801:     let
adamc@801:         fun mapX' ls1 ls2 =
adamc@801:             case (ls1, ls2) of
adamc@801:                 ([], []) => <xml/>
adamc@801:               | (x1 :: ls1, x2 :: ls2) => <xml>{f x1 x2}{mapX' ls1 ls2}</xml>
adamc@801:               | _ => error <xml>ListPair.mapX: Unequal list lengths</xml>
adamc@801:     in
adamc@801:         mapX'
adamc@801:     end
adamc@844: 
adamc@844: fun all [a] [b] f =
adamc@844:     let
adamc@844:         fun all' ls1 ls2 =
adamc@844:             case (ls1, ls2) of
adamc@844:                 ([], []) => True
adamc@844:               | (x1 :: ls1, x2 :: ls2) => f x1 x2 && all' ls1 ls2
adamc@844:               | _ => False
adamc@844:     in
adamc@844:         all'
adamc@844:     end