new kernel basic_ag (with absolute local references)

[helm.git] / helm / software / lambda-delta / basic_ag / bagEnvironment.ml

diff --git a/helm/software/lambda-delta/basic_ag/bagEnvironment.ml b/helm/software/lambda-delta/basic_ag/bagEnvironment.ml
new file mode 100644 (file)
index 0000000..5e6c9f1
--- /dev/null
+++ b/helm/software/lambda-delta/basic_ag/bagEnvironment.ml
@@ -0,0 +1,35 @@
+(*
+    ||M||  This file is part of HELM, an Hypertextual, Electronic        
+    ||A||  Library of Mathematics, developed at the Computer Science     
+    ||T||  Department, University of Bologna, Italy.                     
+    ||I||                                                                
+    ||T||  HELM is free software; you can redistribute it and/or         
+    ||A||  modify it under the terms of the GNU General Public License   
+    \   /  version 2 or (at your option) any later version.              
+     \ /   This software is distributed as is, NO WARRANTY.              
+      V_______________________________________________________________ *)
+
+module U = NUri
+module L = Log
+module H = U.UriHash
+module B = Bag
+
+exception ObjectNotFound of B.message
+
+let hsize = 7000 
+let env = H.create hsize
+let entry = ref 0
+
+(* Internal functions *******************************************************)
+
+let error uri = raise (ObjectNotFound (L.items1 (U.string_of_uri uri)))
+
+(* Interface functions ******************************************************)
+
+let set_obj f obj =
+   let _, uri, b = obj in
+   let obj = !entry, uri, b in
+   incr entry; H.add env uri obj; f obj
+
+let get_obj f uri =
+   try f (H.find env uri) with Not_found -> error uri