--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/navigation.urs	Fri May 06 23:00:22 2011 -0430
@@ -0,0 +1,66 @@
+(* A navigation is a collection of navigation bars (menus) made of links of
+ * which up to one may be marked as active, optional isolated links not part of
+ * menu bars and also optional message or status zones containing xml.  The
+ * programmer can provide a way to format these elements into a collection of
+ * pieces of xml which can then be inserted into themes. *)
+
+functor Make(M : sig
+                 con linkPos :: {Unit}
+                 (* The collection of isolated links.  Should be inferred. *)
+
+                 val linkFolder : folder linkPos
+                 (* Implementation detail; should be inferred. *) 
+
+                 con navbarPos :: {Unit}
+                 (* The collection of navbars. *)
+ 
+                 con msgPos :: {Unit}
+                 (* The collection of optional status or message xml pieces. *)
+
+                 val msgFolder : folder msgPos
+                 (* Implementation detail; should be inferred. *)
+
+                 con linkStyles :: {Type} = mapU (option css_class) linkPos
+                 (* The collection of isolated links, with an optional CSS class
+                  * which will be applied to that link. *) 
+
+                 con themePos :: {Unit}
+                 (* The positions in the theme to generate xml for. *)
+
+                 val linkStyles : $linkStyles
+                 (* The input optional link positions and styles. *)
+
+                 val formatNav : $(mapU xbody navbarPos) -> $(mapU xbody linkPos) -> $(mapU xbody msgPos)
+                                 -> $(mapU xbody themePos)
+                 (* The way to format the collections of navbars, links and message
+                  * zones into pieces of xml for the theme positions. *)
+
+             end) : sig
+
+    con modeLs :: {Type} -> Type = fn r :: {Type} => $(map Navbar.mode r)
+    con barLs :: {Type} -> Type = fn r :: {Type} => $(map Navbar.navBar r)
+
+    con linkLs :: {Unit} -> Type = fn r :: {Unit} => $(mapU (option Navbar.navItem) r)
+    con msgLs :: {Unit} -> Type = fn r :: {Unit} => $(mapU (option xbody) r)
+
+    class shape
+
+    val shape_npos : shape $(mapU xbody M.navbarPos)
+
+    con crush :: {Type} -> Type = fn r :: {Type} => $(map (fn _ => xbody) r) 
+
+    con navigation :: {Type} -> Type = fn m :: {Type} => {Nav : barLs m,
+                                                          Link : linkLs M.linkPos,
+                                                          Msg : msgLs M.msgPos}
+    (* Represents a complete navigation ensemble. *)                                                     
+
+    val mkNav : m ::: {Type} -> shape (crush m) -> modeLs m -> barLs m
+                -> linkLs M.linkPos -> msgLs M.msgPos
+                -> navigation m
+    (* Builds a navigation from input elements of navbars, isolated links and messages. *) 
+
+    val toXml : m ::: {Type} -> folder m -> shape (crush m) -> modeLs m 
+                -> navigation m -> $(mapU xbody M.themePos)
+    (* Renders a navigation to xml pieces suitable for inclusion in a theme. *)
+
+end