diff options
Diffstat (limited to 'lib/ur/monad.ur')
| -rw-r--r-- | lib/ur/monad.ur | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/lib/ur/monad.ur b/lib/ur/monad.ur index 356173fd..d6690839 100644 --- a/lib/ur/monad.ur +++ b/lib/ur/monad.ur @@ -34,6 +34,19 @@ fun foldR2 [K] [m] (_ : monad m) [tf1 :: K -> Type] [tf2 :: K -> Type] [tr :: {K (fn _ _ => return i) [_] fl +fun foldR3 [K] [m] (_ : monad m) [tf1 :: K -> Type] [tf2 :: K -> Type] [tf3 :: K -> Type] [tr :: {K} -> Type] + (f : nm :: Name -> t :: K -> rest :: {K} + -> [[nm] ~ rest] => + tf1 t -> tf2 t -> tf3 t -> tr rest -> m (tr ([nm = t] ++ rest))) + (i : tr []) [r :: {K}] (fl : folder r) = + Top.fold [fn r :: {K} => $(map tf1 r) -> $(map tf2 r) -> $(map tf3 r) -> m (tr r)] + (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest] + (acc : _ -> _ -> _ -> m (tr rest)) r1 r2 r3 => + acc' <- acc (r1 -- nm) (r2 -- nm) (r3 -- nm); + f [nm] [t] [rest] ! r1.nm r2.nm r3.nm acc') + (fn _ _ _ => return i) + [_] fl + fun mapR [K] [m] (_ : monad m) [tf :: K -> Type] [tr :: K -> Type] (f : nm :: Name -> t :: K -> tf t -> m (tr t)) = @@foldR [m] _ [tf] [fn r => $(map tr r)] |