annotate lib/ur/listPair.ur @ 839:b2413e4dd109

List library additions; fix another substructure unification bug
author Adam Chlipala <adamc@hcoop.net>
date Sat, 06 Jun 2009 14:09:30 -0400
parents 78504d97410b
children 74a1e3bdf430
rev   line source
adamc@826 1 fun mapX [a] [b] [ctx ::: {Unit}] f =
adamc@801 2 let
adamc@801 3 fun mapX' ls1 ls2 =
adamc@801 4 case (ls1, ls2) of
adamc@801 5 ([], []) => <xml/>
adamc@801 6 | (x1 :: ls1, x2 :: ls2) => <xml>{f x1 x2}{mapX' ls1 ls2}</xml>
adamc@801 7 | _ => error <xml>ListPair.mapX: Unequal list lengths</xml>
adamc@801 8 in
adamc@801 9 mapX'
adamc@801 10 end