- MySQL mode added to the interpreter

[helm.git] / helm / hxp / hxpXML.ml

diff --git a/helm/hxp/hxpXML.ml b/helm/hxp/hxpXML.ml
new file mode 100644 (file)
index 0000000..7c4dc4c
--- /dev/null
+++ b/helm/hxp/hxpXML.ml
@@ -0,0 +1,91 @@
+(* Copyright (C) 2000, HELM Team.
+ * 
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ * 
+ * HELM is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA  02111-1307, USA.
+ * 
+ * For details, see the HELM World-Wide-Web page,
+ * http://www.cs.unibo.it/helm/.
+ *)
+
+(*  AUTOR: Ferruccio Guidi <fguidi@cs.unibo.it>
+ *)
+
+module T = HxpTypes
+
+module type Type = sig
+
+   type handle
+   
+   val start     : string -> bool -> handle
+
+   val stop     : handle -> unit 
+
+   val next     : handle -> T.xml_object   
+
+   val xnext    : handle -> handle * T.xml_xobject
+
+   val scan_for : handle -> T.xml_xobject -> handle
+
+end 
+
+module Make : Type = struct 
+
+   module L = HxpLexer
+   
+   module P = HxpParser
+
+   type mode_t = Text of in_channel * Lexing.lexbuf 
+               | GZip of Gzip.in_channel * Lexing.lexbuf
+
+   type handle = {mode : mode_t; level : int}
+               
+   let start s filter =
+      let gread gch s n = Gzip.input gch s 0 n in
+      if filter then    
+         let gch = Gzip.open_in (s ^ ".gz") in 
+         let glb = Lexing.from_function (gread gch) in 
+         {mode = GZip (gch, glb); level = 0}
+      else
+         let ch = open_in s in
+        let lb = Lexing.from_channel ch in 
+         {mode = Text (ch, lb); level = 0}
+
+   let stop = function
+      | {mode = GZip (gch, _)} -> Gzip.close_in gch
+      | {mode = Text (ch, _)}  -> close_in ch
+
+   let next h =
+      let lexbuf = match h.mode with
+         | GZip (_, glb) -> glb
+        | Text (_, lb)  -> lb
+      in
+      P.xml L.xml_token lexbuf
+
+   let xnext h =
+      let obj = next h in
+      match obj with
+      | T.XML_Open _  -> {h with level = succ h.level}, (obj, h.level)
+      | T.XML_Close _ -> {h with level = pred h.level}, (obj, pred h.level)
+      | _             -> h, (obj, h.level)
+
+   let rec scan_for h xobj = 
+      let h, curr_xobj = xnext h in
+      if curr_xobj = xobj then h else scan_for h xobj
+
+end