Mercurial > urweb
annotate lib/ur/option.ur @ 845:6725d73c3c31
Mark current as effectful; add List functions
| author | Adam Chlipala <adamc@hcoop.net> |
|---|---|
| date | Tue, 09 Jun 2009 11:12:34 -0400 |
| parents | 74a1e3bdf430 |
| children | 0d30e6338c65 |
| rev | line source |
|---|---|
| adamc@841 | 1 datatype t = datatype Basis.option |
| adamc@841 | 2 |
| adamc@841 | 3 fun isSome [a] x = |
| adamc@841 | 4 case x of |
| adamc@841 | 5 None => False |
| adamc@841 | 6 | Some _ => True |
| adamc@844 | 7 |
| adamc@844 | 8 fun mp [a] [b] f x = |
| adamc@844 | 9 case x of |
| adamc@844 | 10 None => None |
| adamc@844 | 11 | Some y => Some (f y) |