X-Git-Url: http://git.nguyen.vg/gitweb/?a=blobdiff_plain;f=tree.ml;h=2218c2843f913208ce5e758fd99ccf266b82fd82;hb=8dbe70986b1229d003298d945992852fb27c7aee;hp=6c3cc1bf483f0a650010a1524a75269c2263562e;hpb=7dea5fd8bedede27d4d601f85630a249bfab420b;p=SXSI%2Fxpathcomp.git

diff --git a/tree.ml b/tree.ml
index 6c3cc1b..2218c28 100644
--- a/tree.ml
+++ b/tree.ml
@@ -18,8 +18,11 @@ sig
   val tag_pool : t -> Tag.pool
   val string : t -> string
   val descr : t -> descr
+  val is_node : t -> bool
   val left : t -> t
   val right : t -> t
+  val first_child : t -> t
+  val next_sibling : t -> t
   val parent : t -> t
   val id : t -> int
   val tag : t -> Tag.t
@@ -185,6 +188,7 @@ struct
 			       let compare = (-) end)
 			
     end
+    let is_node = function { node=Node(_) } -> true | _ -> false
     let get_string t (i:string_content) = Text.get_text t.doc i
     open Tree      	       
     let node_of_t t = { doc= t;