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Diffstat (limited to 'lib/ur/option.ur')
| -rw-r--r-- | lib/ur/option.ur | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/ur/option.ur b/lib/ur/option.ur index 0aa07a2d..5c89fc9d 100644 --- a/lib/ur/option.ur +++ b/lib/ur/option.ur @@ -1,5 +1,11 @@ datatype t = datatype Basis.option +val monad = mkMonad {Return = @@Some, + Bind = fn [a] [b] (m1 : t a) (m2 : a -> t b) => + case m1 of + None => None + | Some v => m2 v} + fun eq [a] (_ : eq a) = mkEq (fn x y => case (x, y) of |