This big commit addresses two problems:

  1- Management of the name-space in a modular development / sharing of non-logical objects.
  2- Performance of atomic module operations (adding a module to the environment, subtyping ...).

1-
There are 3 module constructions which derive equalities on fields from a module to another:
Let P be a module path and foo a field of P

Module M := P.

Module M.
 Include P.
 ...
End M.

Declare Module K : S with Module M := P.

In this 3 cases we don't want to be bothered by the duplication of names. 
Of course, M.foo delta reduce to P.foo but many non-logical features of coq 
do not work modulo conversion (they use eq_constr or constr_pat object). 
To engender a transparent name-space (ie using P.foo or M.foo is the same thing) 
we quotient the name-space by the equivalence relation on names induced by the 
3 constructions above.
To implement this, the types constant and mutual_inductive are now couples of 
kernel_names. The first projection correspond to the name used by the user and the second
projection to the canonical name, for example the internal name of M.foo is
(M.foo,P.foo). 
So:
*************************************************************************************
*  Use the eq_(con,mind,constructor,gr,egr...) function and not = on names values   *
*************************************************************************************

Map and Set indexed on names are ordered on user name for the kernel side
and on canonical name outside. Thus we have sharing of notation, hints... for free 
(also for a posteriori declaration of them, ex: a notation on M.foo will be 
avaible on P.foo). If you want to use this, use the appropriate compare function
defined in name.ml or libnames.ml.


2-
No more time explosion (i hoppe) when using modules i have re-implemented atomic
module operations so that they are all linear in the size of the module. We also
have no more unique identifier (internal module names) for modules, it is now based 
on a section_path like mechanism => we have less substitutions to perform at require,
module closing and subtyping but we pre-compute more information hence if we instanciate 
several functors then we have bigger vo.


Last thing, the checker will not work well on vo(s) that contains one of the 3 constructions
above, i will work on it soon...



git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@12406 85f007b7-540e-0410-9357-904b9bb8a0f7

3 files changed, 113 insertions, 0 deletions

diff --git a/lib/lib.mllib b/lib/lib.mllib
index 2321abd1b0..56fe32cbd5 100644
--- a/lib/lib.mllib
+++ b/lib/lib.mllib
@@ -13,6 +13,7 @@ Edit
 Gset
 Gmap
 Tlm
+tries
 Gmapl
 Profile
 Explore
diff --git a/lib/tries.ml b/lib/tries.ml
new file mode 100644
index 0000000000..1159ea2331
--- /dev/null
+++ b/lib/tries.ml
@@ -0,0 +1,78 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+
+
+module Make = 
+  functor (X : Set.OrderedType) ->
+    functor (Y : Map.OrderedType) ->
+struct
+  module T_dom = Set.Make(X) 
+  module T_codom = Map.Make(Y) 
+
+  type t = Node of T_dom.t * t T_codom.t
+
+  let codom_to_list m = T_codom.fold (fun x y l -> (x,y)::l) m []
+
+  let codom_rng m = T_codom.fold (fun _ y acc -> y::acc) m []
+
+  let codom_dom m = T_codom.fold (fun x _ acc -> x::acc) m []
+
+  let empty = Node (T_dom.empty, T_codom.empty)
+
+  let map (Node (_,m)) lbl = T_codom.find lbl m
+
+  let xtract (Node (hereset,_)) = T_dom.elements hereset
+    
+  let dom (Node (_,m)) = codom_dom m
+
+  let in_dom (Node (_,m)) lbl = T_codom.mem lbl m
+
+  let is_empty_node (Node(a,b)) = (T_dom.elements a = []) & (codom_to_list b = [])
+
+let assure_arc m lbl =
+  if T_codom.mem lbl m then 
+    m
+  else 
+    T_codom.add lbl (Node (T_dom.empty,T_codom.empty)) m
+
+let cleanse_arcs (Node (hereset,m)) =
+  let l = codom_rng m in 
+  Node(hereset, if List.for_all is_empty_node l then T_codom.empty else m)
+
+let rec at_path f (Node (hereset,m)) = function
+  | [] -> 
+      cleanse_arcs (Node(f hereset,m))
+  | h::t ->
+      let m = assure_arc m h in 
+      cleanse_arcs (Node(hereset,
+                         T_codom.add h (at_path f (T_codom.find h m) t) m))
+
+let add tm (path,v) =
+  at_path (fun hereset -> T_dom.add v hereset) tm path
+    
+let rmv tm (path,v) =
+  at_path (fun hereset -> T_dom.remove v hereset) tm path
+
+let app f tlm = 
+  let rec apprec pfx (Node(hereset,m)) =
+    let path = List.rev pfx in 
+    T_dom.iter (fun v -> f(path,v)) hereset;
+    T_codom.iter (fun l tm -> apprec (l::pfx) tm) m
+  in 
+  apprec [] tlm
+    
+let to_list tlm = 
+  let rec torec pfx (Node(hereset,m)) =
+    let path = List.rev pfx in 
+    List.flatten((List.map (fun v -> (path,v)) (T_dom.elements hereset))::
+		 (List.map (fun (l,tm) -> torec (l::pfx) tm) (codom_to_list m)))
+  in 
+  torec [] tlm
+
+end
diff --git a/lib/tries.mli b/lib/tries.mli
new file mode 100644
index 0000000000..342c81ecdc
--- /dev/null
+++ b/lib/tries.mli
@@ -0,0 +1,34 @@
+
+
+
+
+
+module Make :
+  functor (X : Set.OrderedType) ->
+    functor (Y : Map.OrderedType) ->
+sig
+     
+  type t 
+    
+  val empty : t
+      
+  (* Work on labels, not on paths. *)
+
+  val map : t -> Y.t -> t
+
+  val xtract : t -> X.t list
+    
+  val dom : t -> Y.t list
+
+  val in_dom : t -> Y.t -> bool
+
+  (* Work on paths, not on labels. *)
+
+  val add : t -> Y.t list * X.t -> t
+  
+  val rmv : t -> Y.t list * X.t -> t 
+
+  val app : ((Y.t list * X.t) -> unit) -> t -> unit
+    
+  val to_list : t -> (Y.t list * X.t) list
+end