annotate lib/ur/listPair.ur @ 1511:e717e2b56b21

Tutorial: link to demo and manual
author Adam Chlipala <adam@chlipala.net>
date Sun, 17 Jul 2011 14:49:52 -0400
parents 1c2f335297b7
children 5c30eea7aa78
rev   line source
adamc@850 1 fun foldlAbort [a] [b] [c] f =
adamc@846 2 let
adamc@850 3 fun foldlAbort' acc ls1 ls2 =
adamc@846 4 case (ls1, ls2) of
adamc@846 5 ([], []) => Some acc
adamc@846 6 | (x1 :: ls1, x2 :: ls2) =>
adamc@846 7 (case f x1 x2 acc of
adamc@846 8 None => None
adamc@850 9 | Some acc' => foldlAbort' acc' ls1 ls2)
adamc@846 10 | _ => None
adamc@846 11 in
adamc@850 12 foldlAbort'
adamc@846 13 end
adamc@846 14
adamc@826 15 fun mapX [a] [b] [ctx ::: {Unit}] f =
adamc@801 16 let
adamc@801 17 fun mapX' ls1 ls2 =
adamc@801 18 case (ls1, ls2) of
adamc@801 19 ([], []) => <xml/>
adamc@801 20 | (x1 :: ls1, x2 :: ls2) => <xml>{f x1 x2}{mapX' ls1 ls2}</xml>
adamc@801 21 | _ => error <xml>ListPair.mapX: Unequal list lengths</xml>
adamc@801 22 in
adamc@801 23 mapX'
adamc@801 24 end
adamc@844 25
adamc@844 26 fun all [a] [b] f =
adamc@844 27 let
adamc@844 28 fun all' ls1 ls2 =
adamc@844 29 case (ls1, ls2) of
adamc@844 30 ([], []) => True
adamc@844 31 | (x1 :: ls1, x2 :: ls2) => f x1 x2 && all' ls1 ls2
adamc@844 32 | _ => False
adamc@844 33 in
adamc@844 34 all'
adamc@844 35 end