6 files changed, 79 insertions, 2 deletions
diff --git a/demo/ref.ur b/demo/ref.ur
index 4030b6fa..1e406dd9 100644
--- a/demo/ref.ur
+++ b/demo/ref.ur
@@ -1,11 +1,9 @@
 structure IR = RefFun.Make(struct
                                type t = int
-                               val inj = _
                            end)
 
 structure SR = RefFun.Make(struct
                                type t = string
-                               val inj = _
                            end)
 
 fun main () =
diff --git a/demo/tree.ur b/demo/tree.ur
new file mode 100644
index 00000000..06a30cf9
--- /dev/null
+++ b/demo/tree.ur
@@ -0,0 +1,15 @@
+table t : { Id : int, Parent : option int, Nam : string }
+
+open TreeFun.Make(struct
+                      val tab = t
+                  end)
+
+fun row r = <xml>
+  #{[r.Id]}: {[r.Nam]}
+</xml>
+
+fun main () =
+    xml <- tree row None;
+    return <xml><body>
+      {xml}
+    </body></xml>
diff --git a/demo/tree.urp b/demo/tree.urp
new file mode 100644
index 00000000..2270dd06
--- /dev/null
+++ b/demo/tree.urp
@@ -0,0 +1,6 @@
+debug
+database dbname=tree
+sql tree.sql
+
+treeFun
+tree
diff --git a/demo/tree.urs b/demo/tree.urs
new file mode 100644
index 00000000..6ac44e0b
--- /dev/null
+++ b/demo/tree.urs
@@ -0,0 +1 @@
+val main : unit -> transaction page
diff --git a/demo/treeFun.ur b/demo/treeFun.ur
new file mode 100644
index 00000000..60633695
--- /dev/null
+++ b/demo/treeFun.ur
@@ -0,0 +1,35 @@
+functor Make(M : sig
+                 type key
+                 con id :: Name
+                 con parent :: Name
+                 con cols :: {Type}
+                 constraint [id] ~ [parent]
+                 constraint [id, parent] ~ cols
+
+                 val key_inj : sql_injectable key
+                 val option_key_inj : sql_injectable (option key)
+
+                 table tab : [id = key, parent = option key] ++ cols
+             end) = struct
+
+    open M
+
+    fun tree (f : $([id = key, parent = option key] ++ cols) -> xbody)
+             (root : option M.key) =
+        let
+            fun recurse (root : option key) =
+                queryX' (SELECT * FROM tab WHERE tab.{parent} = {root})
+                        (fn r =>
+                            children <- recurse (Some r.Tab.id);
+                            return <xml>
+                              <li> {f r.Tab}</li>
+                              
+                              <ul>
+                                {children}
+                              </ul>
+                            </xml>)
+        in
+            recurse root
+        end
+
+end
diff --git a/demo/treeFun.urs b/demo/treeFun.urs
new file mode 100644
index 00000000..501a0575
--- /dev/null
+++ b/demo/treeFun.urs
@@ -0,0 +1,22 @@
+functor Make(M : sig
+                 type key
+                 con id :: Name
+                 con parent :: Name
+                 con cols :: {Type}
+                 constraint [id] ~ [parent]
+                 constraint [id, parent] ~ cols
+
+                 val key_inj : sql_injectable key
+                 val option_key_inj : sql_injectable (option key)
+
+                 table tab : [id = key, parent = option key] ++ cols
+             end) : sig
+
+    con id = M.id
+    con parent = M.parent
+
+    val tree : ($([id = M.key, parent = option M.key] ++ M.cols) -> xbody)
+               -> option M.key
+               -> transaction xbody
+
+end