Mercurial > urweb
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 |