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| author |  Adam Chlipala <adam@chlipala.net> | 2018-04-14 15:15:07 -0400 |
|---|---|---|
| committer | Adam Chlipala <adam@chlipala.net> | 2018-04-14 15:15:07 -0400 |
| commit | 0cadb1a719bc515af2449ac966e545a6599aee4d (patch) | |
| tree | a350817dec17293fa409151d868ec6a4f87f3a8c /lib/ur/list.ur | |
| parent | 1fef19035d2f3388e9ab0dad1889a4cad5c1ca3e (diff) | |
List.findM
Diffstat (limited to 'lib/ur/list.ur')
| -rw-r--r-- | lib/ur/list.ur | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/lib/ur/list.ur b/lib/ur/list.ur index a7296552..95d6fbc8 100644 --- a/lib/ur/list.ur +++ b/lib/ur/list.ur @@ -255,6 +255,21 @@ fun find [a] f = find' end +fun findM [m] (_ : monad m) [a] f = + let + fun find' ls = + case ls of + [] => return None + | x :: ls => + b <- f x; + if b then + return (Some x) + else + find' ls + in + find' + end + fun search [a] [b] f = let fun search' ls = |