Temporary commit.

[SXSI/xpathcomp.git] / src / grammar.ml

diff --git a/src/grammar.ml b/src/grammar.ml
index 6537cb2..7795150 100644 (file)
--- a/src/grammar.ml
+++ b/src/grammar.ml
@@ -1,7 +1,84 @@
 type t
 
+type node = [ `Grammar ] Node.t
+type symbol = [ `Terminal | `NonTerminal | `Parameter ] Node.t
+
+type p_symbol = [ `Parameter ] Node.t
+type n_symbol = [ `NonTerminal ] Node.t
+type t_symbol = [ `Terminal ] Node.t
+
+type partial = Node of n_symbol * partial array | Leaf of node
+
+
+
+
+external is_nil : t -> t_symbol -> bool = "caml_grammar_is_nil"
+external get_tag : t -> t_symbol -> string = "caml_grammar_get_tag"
+
+external get_symbol_at : t -> symbol -> node -> symbol = "caml_grammar_get_symbol_at"
+external first_child : t -> symbol -> node -> node = "caml_grammar_first_child"
+external next_sibling : t -> symbol -> node -> node = "caml_grammar_next_sibling"
+
+
+let is_non_terminal (n : symbol) =
+  let n = Node.to_int n in
+  n land 3 == 0
+
+let is_terminal (n : symbol) =
+  let n = Node.to_int n in
+  n land 3 == 1
+
+let is_parameter (n : symbol) =
+  let n = Node.to_int n in
+  n land 3 == 2
+
+
+external parameter : symbol -> p_symbol = "%identity"
+external terminal : symbol -> t_symbol = "%identity"
+external non_terminal : symbol -> n_symbol = "%identity"
+
+
+let num_params (n : n_symbol) =
+  let n = Node.to_int n in
+  (n lsr 2) land 0xf
+
 external load : Unix.file_descr -> bool -> t = "caml_grammar_load"
 
+
+
+let traversal g =
+  let start_symbol = (Node.of_int 0) in
+  let rec start_loop idx =
+    if idx >= Node.null then begin
+      let symbol = get_symbol_at g start_symbol idx in
+      if is_terminal symbol then
+       let ts = terminal symbol in
+       if is_nil g ts then () else
+         let str = get_tag g ts in
+         Printf.printf "<%s>%!" str;
+         start_loop (first_child g start_symbol idx);
+         start_loop (next_sibling g start_symbol idx);
+         Printf.printf "</%s>%!" str;
+      else
+       let tn = non_terminal symbol in
+       let nparam = num_params tn in
+       let child = ref (first_child g start_symbol idx) in
+       let a_param = Array.init nparam
+         (fun _ -> let c = !child in
+                   child := next_sibling g start_symbol c;
+                   c)
+       in
+       rule_loop tn a_param
+    end
+  and rule_loop (nterm : [ `NonTerminal | `Terminal ] Node.t)  a_param =
+    let 
+
+  in
+  start_loop (Node.of_int 0)
+;;
+
+
+
 let load filename bp =
   let fd = Unix.openfile filename [ Unix.O_RDONLY ] 0o600 in
   let g =
@@ -11,3 +88,4 @@ let load filename bp =
   Unix.close fd;
   g
 
+