diff options
| -rw-r--r-- | lib/ur/monad.ur | 14 | ||||
| -rw-r--r-- | lib/ur/monad.urs | 10 |
2 files changed, 24 insertions, 0 deletions
diff --git a/lib/ur/monad.ur b/lib/ur/monad.ur index 689e6b26..211b6cbd 100644 --- a/lib/ur/monad.ur +++ b/lib/ur/monad.ur @@ -78,3 +78,17 @@ fun mapR2 [K] [m] (_ : monad m) [tf1 :: K -> Type] [tf2 :: K -> Type] [tr :: K - v' <- f [nm] [t] v1 v2; return (acc ++ {nm = v'})) {} + +fun foldMapR [K] [m] (_ : monad m) [tf :: K -> Type] [tf' :: K -> Type] [tr :: {K} -> Type] + (f : nm :: Name -> t :: K -> rest :: {K} + -> [[nm] ~ rest] => + tf t -> tr rest -> m (tf' t * tr ([nm = t] ++ rest))) + (i : tr []) [r ::: {K}] (fl : folder r) = + @Top.fold [fn r :: {K} => $(map tf r) -> m ($(map tf' r) * tr r)] + (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest] + (acc : _ -> m ($(map tf' rest) * tr rest)) r => + p <- acc (r -- nm); + p' <- f [nm] [t] [rest] ! r.nm p.2; + return ({nm = p'.1} ++ p.1, p'.2)) + (fn _ => return ({}, i)) + fl diff --git a/lib/ur/monad.urs b/lib/ur/monad.urs index 05f201e0..cf20dd0f 100644 --- a/lib/ur/monad.urs +++ b/lib/ur/monad.urs @@ -50,3 +50,13 @@ val mapR2 : K --> m ::: (Type -> Type) -> monad m -> tr :: (K -> Type) -> (nm :: Name -> t :: K -> tf1 t -> tf2 t -> m (tr t)) -> r ::: {K} -> folder r -> $(map tf1 r) -> $(map tf2 r) -> m ($(map tr r)) + +val foldMapR : K --> m ::: (Type -> Type) -> monad m + -> tf :: (K -> Type) + -> tf' :: (K -> Type) + -> tr :: ({K} -> Type) + -> (nm :: Name -> t :: K -> rest :: {K} + -> [[nm] ~ rest] => + tf t -> tr rest -> m (tf' t * tr ([nm = t] ++ rest))) + -> tr [] + -> r ::: {K} -> folder r -> $(map tf r) -> m ($(map tf' r) * tr r) |