Monad.foldMapR

1 files changed, 10 insertions, 0 deletions

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)