DISCLAIMER

==========

This big patch is commited here with a HUGE experimental tag on it. It
is probably not a finished job. The aim of committing it now, as
agreed with Hugo, is to get some feedback from potential users to
identify more clearly the directions the implementation could take. So
please feel free to mail me any remarks, bug reports or advices at
<puech@cs.unibo.it>.

Here are the changes induced by it :

For the user
============

* Search tools have been reimplemented to be faster and more
  general. Affected are [SearchPattern], [SearchRewrite] and [Search]
  (not [SearchAbout] yet). Changes are:

  - All of them accept general constructions, and previous syntactical
    limitations are abolished. In particular, one can for example
    [SearchPattern (nat -> Prop)], which will find [isSucc], but also
    [le], [gt] etc.

  - Patterns are typed. This means that you cannot search mistyped
    expressions anymore. I'm not sure if it's a good or a bad thing
    though (especially regarding coercions)...

* New tool to automatically infer (some) Record/Typeclasses instances.
  Usage : [Record/Class *Infer* X := ...] flags a record/class as
  subject to instance search. There is also an option to
  activate/deactivate the search [Set/Unset Autoinstance].  It works
  by finding combinations of definitions (actually all kinds of
  objects) which forms a record instance, possibly parameterized. It
  is activated at two moments:

  - A complete search is done when defining a new record, to find all
    possible instances that could have been formed with past
    definitions. Example: 

      Require Import List.
      Record Infer Monoid A (op:A->A->A) e := 
        { assoc : forall x y z, op x (op y z) = op (op x y) z; 
          idl : forall x, x = op x e ; 
          idr : forall x, x = op e x }.

      new instance Monoid_autoinstance_1 : (Monoid nat plus 0)
      [...]

  - At each new declaration (Definition, Axiom, Inductive), a search
    is made to find instances involving the new object. Example:

      Parameter app_nil_beg : forall A (l:list A), l = nil ++ l.

      new instance Build_Monoid_autoinstance_12 :
      (forall H : Type, Monoid (list H) app nil) :=
      (fun H : Type =>
      Build_Monoid (list H) app nil ass_app (app_nil_beg H)
      (app_nil_end H))


For the developper
==================

* New yet-to-be-named datastructure in [lib/dnet.ml]. Should do
  efficient one-to-many or many-to-one non-linear first-order
  filtering, faster than traditional methods like discrimination nets
  (so yes, the name of the file should probably be changed).

* Comes with its application to Coq's terms
  [pretyping/term_dnet.ml]. Terms are represented so that you can
  search for patterns under products as fast as you would do not under
  products, and facilities are provided to express other kind of
  searches (head of application, under equality, whatever you need
  that can be expressed as a pattern)

* A global repository of all objects defined and imported is
  maintained [toplevel/libtypes.ml], with all search facilities
  described before.

* A certain kind of proof search in [toplevel/autoinstance.ml]. For
  the moment it is specialized on finding instances, but it should be
  generalizable and reusable (more on this in a few months :-).


The bad news
============

* Compile time should increase by 0 to 15% (depending on the size of
  the Requires done). This could be optimized greatly by not
  performing substitutions on modules which are not functors I
  think. There may also be some inefficiency sources left in my code
  though...

* Vo's also gain a little bit of weight (20%). That's inevitable if I
  wanted to store the big datastructure of objects, but could also be
  optimized some more.


git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@11794 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 109 insertions, 0 deletions

diff --git a/toplevel/libtypes.ml b/toplevel/libtypes.ml
new file mode 100644
index 0000000000..6fd49b15b9
--- /dev/null
+++ b/toplevel/libtypes.ml
@@ -0,0 +1,109 @@
+(************************************************************************)
+(*  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        *)
+(************************************************************************)
+
+open Term
+open Summary
+open Libobject
+
+(* 
+ * Module construction
+ *)
+  
+let reduce c = Reductionops.head_unfold_under_prod 
+  (Auto.Hint_db.transparent_state (Auto.searchtable_map "typeclass_instances"))
+  (Global.env()) Evd.empty c
+
+module TypeDnet = Term_dnet.Make(struct 
+				   type t = Libnames.global_reference
+				   let compare = Pervasives.compare
+				   let subst s gr = fst (Libnames.subst_global s gr)
+				   let constr_of = Global.type_of_global
+				 end)
+  (struct let reduce = reduce 
+	  let direction = false end)
+
+type result = Libnames.global_reference * (constr*existential_key) * Termops.subst
+
+let all_types = ref TypeDnet.empty
+let defined_types = ref TypeDnet.empty
+
+(*
+ * Bookeeping & States
+ *)
+
+let freeze () = 
+  (!all_types,!defined_types)
+
+let unfreeze (lt,dt) = 
+  all_types := lt; 
+  defined_types := dt
+
+let init () = 
+  all_types := TypeDnet.empty; 
+  defined_types := TypeDnet.empty
+
+let _ = 
+  declare_summary "type-library-state"
+    { freeze_function = freeze;
+      unfreeze_function = unfreeze;
+      init_function = init;
+      survive_module = false;
+      survive_section = false }
+
+let load (_,d) =
+(*  Profile.print_logical_stats !all_types;
+  Profile.print_logical_stats d;*)
+  all_types := TypeDnet.union d !all_types 
+
+let subst s t = TypeDnet.subst s t
+(*
+let subst_key = Profile.declare_profile "subst"
+let subst a b = Profile.profile2 subst_key TypeDnet.subst a b
+
+let load_key = Profile.declare_profile "load"
+let load a = Profile.profile1 load_key load a
+*)
+let (input,output) = 
+  declare_object
+    { (default_object "LIBTYPES") with
+	load_function = (fun _ -> load);
+	subst_function = (fun (_,s,t) -> subst s t);
+	export_function = (fun x -> Some x);
+	classify_function = (fun (_,x) -> Substitute x) 
+    }
+
+let update () = Lib.add_anonymous_leaf (input !defined_types)
+
+(* 
+ * Search interface
+ *)
+
+let search_pattern pat = TypeDnet.search_pattern !all_types pat
+let search_concl pat = TypeDnet.search_concl !all_types pat
+let search_head_concl pat = TypeDnet.search_head_concl !all_types pat
+let search_eq_concl eq pat = TypeDnet.search_eq_concl !all_types eq pat
+
+let add typ gr =
+  defined_types := TypeDnet.add typ gr !defined_types;
+  all_types := TypeDnet.add typ gr !all_types
+(*
+let add_key = Profile.declare_profile "add"
+let add a b = Profile.profile1 add_key add a b
+*)
+    
+(* 
+ * Hooks declaration 
+ *)
+
+let _ = Declare.add_cache_hook 
+  ( fun sp ->
+      let gr = Nametab.absolute_reference sp in
+      let ty = Global.type_of_global gr in
+      add ty gr )
+
+let _ = Declaremods.set_end_library_hook update