5 files changed, 35 insertions, 8 deletions
diff --git a/lib/js/urweb.js b/lib/js/urweb.js
index 3d4dbea2..dd66b55e 100644
--- a/lib/js/urweb.js
+++ b/lib/js/urweb.js
@@ -223,12 +223,17 @@ function lastParent() {
   return pos.parentNode;
 }
 
+function parent() {
+  return thisScript ? thisScript.parentNode : lastParent();
+}
+
 function addNode(node) {
   if (thisScript) {
     thisScript.parentNode.appendChild(node);
     thisScript.parentNode.removeChild(thisScript);
-  } else
+  } else {
     lastParent().appendChild(node);
+  }
 }
 
 function setHTML(html) {
@@ -266,10 +271,8 @@ function runScripts(node) {
 
 // Dynamic tree entry points
 
-var dynDepth = 0;
-
 function dyn(s) {
-  var x = document.createElement("span");
+  var x = parent();
   x.dead = false;
   x.signal = s;
   x.sources = null;
@@ -298,7 +301,6 @@ function dyn(s) {
     x.closures = cls.v;
     runScripts(x);
   };
-  addNode(x);
   populate(x);
 }
 
diff --git a/lib/ur/monad.ur b/lib/ur/monad.ur
index 41f44d3a..73001094 100644
--- a/lib/ur/monad.ur
+++ b/lib/ur/monad.ur
@@ -5,3 +5,5 @@ fun exec [m ::: Type -> Type] (_ : monad m) [ts ::: {Type}] r (fd : folder ts) =
         others <- acc;
         return ({nm = this} ++ others))
     (return {}) [ts] fd r
+
+fun ignore [m ::: Type -> Type] (_ : monad m) [t] (v : m t) = x <- v; return ()
diff --git a/lib/ur/monad.urs b/lib/ur/monad.urs
index cfe0ef8e..b3cb3d6f 100644
--- a/lib/ur/monad.urs
+++ b/lib/ur/monad.urs
@@ -1,2 +1,5 @@
 val exec : m ::: (Type -> Type) -> monad m -> ts ::: {Type}
            -> $(map m ts) -> folder ts -> m $ts
+
+val ignore : m ::: (Type -> Type) -> monad m -> t ::: Type
+             -> m t -> m unit
diff --git a/lib/ur/top.ur b/lib/ur/top.ur
index 785a9c8c..3dac7ff0 100644
--- a/lib/ur/top.ur
+++ b/lib/ur/top.ur
@@ -51,7 +51,7 @@ end
 
 fun not b = if b then False else True
 
-con idT (t :: Type) = t
+con id = K ==> fn t :: K => t
 con record (t :: {Type}) = $t
 con fst = K1 ==> K2 ==> fn t :: (K1 * K2) => t.1
 con snd = K1 ==> K2 ==> fn t :: (K1 * K2) => t.2
@@ -92,11 +92,24 @@ fun read_option [t ::: Type] (_ : read t) =
 fun txt [t] [ctx ::: {Unit}] [use ::: {Type}] (_ : show t) (v : t) =
     cdata (show v)
 
+fun mp [K] [tf1 :: K -> Type] [tf2 :: K -> Type] (f : t ::: K -> tf1 t -> tf2 t) [r :: {K}] (fl : folder r) =
+    fl [fn r :: {K} => $(map tf1 r) -> $(map tf2 r)]
+    (fn [nm :: Name] [t :: K] [rest :: {K}] [[nm] ~ rest] acc r =>
+        acc (r -- nm) ++ {nm = f r.nm})
+    (fn _ => {})
+
+fun map2 [K1] [K2] [tf1 :: K1 -> Type] [tf2 :: K2 -> Type] [tf :: K1 -> K2]
+         (f : t ::: K1 -> tf1 t -> tf2 (tf t)) [r :: {K1}] (fl : folder r) =
+    fl [fn r :: {K1} => $(map tf1 r) -> $(map tf2 (map tf r))]
+    (fn [nm :: Name] [t :: K1] [rest :: {K1}] [[nm] ~ rest] acc r =>
+        acc (r -- nm) ++ {nm = f r.nm})
+    (fn _ => {})
+
 fun foldUR [tf :: Type] [tr :: {Unit} -> Type]
            (f : nm :: Name -> rest :: {Unit}
                 -> [[nm] ~ rest] =>
                       tf -> tr rest -> tr ([nm] ++ rest))
-           (i : tr []) [r :: {Unit}] (fl : folder r)=
+           (i : tr []) [r :: {Unit}] (fl : folder r) =
     fl [fn r :: {Unit} => $(mapU tf r) -> tr r]
        (fn [nm :: Name] [t :: Unit] [rest :: {Unit}] [[nm] ~ rest] acc r =>
            f [nm] [rest] ! r.nm (acc (r -- nm)))
diff --git a/lib/ur/top.urs b/lib/ur/top.urs
index 4ed64075..33c90651 100644
--- a/lib/ur/top.urs
+++ b/lib/ur/top.urs
@@ -21,7 +21,7 @@ end
 
 val not : bool -> bool
 
-con idT = fn t :: Type => t
+con id = K ==> fn t :: K => t
 con record = fn t :: {Type} => $t
 con fst = K1 ==> K2 ==> fn t :: (K1 * K2) => t.1
 con snd = K1 ==> K2 ==> fn t :: (K1 * K2) => t.2
@@ -45,6 +45,13 @@ val read_option : t ::: Type -> read t -> read (option t)
 val txt : t ::: Type -> ctx ::: {Unit} -> use ::: {Type} -> show t -> t
           -> xml ctx use []
 
+val mp : K --> tf1 :: (K -> Type) -> tf2 :: (K -> Type)
+         -> (t ::: K -> tf1 t -> tf2 t)
+         -> r :: {K} -> folder r -> $(map tf1 r) -> $(map tf2 r)
+val map2 : K1 --> K2 --> tf1 :: (K1 -> Type) -> tf2 :: (K2 -> Type) -> tf :: (K1 -> K2)
+           -> (t ::: K1 -> tf1 t -> tf2 (tf t))
+           -> r :: {K1} -> folder r -> $(map tf1 r) -> $(map tf2 (map tf r))
+
 val foldUR : tf :: Type -> tr :: ({Unit} -> Type)
              -> (nm :: Name -> rest :: {Unit}
                  -> [[nm] ~ rest] =>