From 9043add656177eeac1491a73d2f3ab92bec0013c Mon Sep 17 00:00:00 2001
From: Benjamin Barenblat <bbaren@debian.org>
Date: Sat, 29 Dec 2018 14:31:27 -0500
Subject: Imported Upstream version 8.8.2

---
 lib/hashcons.ml | 182 --------------------------------------------------------
 1 file changed, 182 deletions(-)
 delete mode 100644 lib/hashcons.ml

(limited to 'lib/hashcons.ml')

diff --git a/lib/hashcons.ml b/lib/hashcons.ml
deleted file mode 100644
index 4eaacf91..00000000
--- a/lib/hashcons.ml
+++ /dev/null
@@ -1,182 +0,0 @@
-(************************************************************************)
-(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
-(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2016     *)
-(*   \VV/  **************************************************************)
-(*    //   *      This file is distributed under the terms of the       *)
-(*         *       GNU Lesser General Public License Version 2.1        *)
-(************************************************************************)
-
-(* Hash consing of datastructures *)
-
-(* The generic hash-consing functions (does not use Obj) *)
-
-(* [t] is the type of object to hash-cons
- * [u] is the type of hash-cons functions for the sub-structures
- *   of objects of type t (u usually has the form (t1->t1)*(t2->t2)*...).
- * [hashcons u x] is a function that hash-cons the sub-structures of x using
- *   the hash-consing functions u provides.
- * [eq] is a comparison function. It is allowed to use physical equality
- *   on the sub-terms hash-consed by the hashcons function.
- * [hash] is the hash function given to the Hashtbl.Make function
- *
- * Note that this module type coerces to the argument of Hashtbl.Make.
- *)
-
-module type HashconsedType =
-  sig
-    type t
-    type u
-    val hashcons :  u -> t -> t
-    val eq : t -> t -> bool
-    val hash : t -> int
-  end
-
-(** The output is a function [generate] such that [generate args] creates a
-    hash-table of the hash-consed objects, together with [hcons], a function
-    taking a table and an object, and hashcons it. For simplicity of use, we use
-    the wrapper functions defined below. *)
-
-module type S =
-  sig
-    type t
-    type u
-    type table
-    val generate : u -> table
-    val hcons : table -> t -> t
-    val stats : table -> Hashset.statistics
-  end
-
-module Make (X : HashconsedType) : (S with type t = X.t and type u = X.u) =
-  struct
-    type t = X.t
-    type u = X.u
-
-    (* We create the type of hashtables for t, with our comparison fun.
-     * An invariant is that the table never contains two entries equals
-     * w.r.t (=), although the equality on keys is X.eq. This is
-     * granted since we hcons the subterms before looking up in the table.
-     *)
-    module Htbl = Hashset.Make(X)
-
-    type table = (Htbl.t * u)
-
-    let generate u =
-      let tab = Htbl.create 97 in
-      (tab, u)
-
-    let hcons (tab, u) x =
-      let y = X.hashcons u x in
-      Htbl.repr (X.hash y) y tab
-
-    let stats (tab, _) = Htbl.stats tab
-
-  end
-
-(* A few useful wrappers:
- * takes as argument the function [generate] above and build a function of type
- * u -> t -> t that creates a fresh table each time it is applied to the
- * sub-hcons functions. *)
-
-(* For non-recursive types it is quite easy. *)
-let simple_hcons h f u =
-  let table = h u in
-  fun x -> f table x
-
-(* For a recursive type T, we write the module of sig Comp with u equals
- * to (T -> T) * u0
- * The first component will be used to hash-cons the recursive subterms
- * The second one to hashcons the other sub-structures.
- * We just have to take the fixpoint of h
- *)
-let recursive_hcons h f u =
-  let loop = ref (fun _ -> assert false) in
-  let self x = !loop x in
-  let table = h (self, u) in
-  let hrec x = f table x in
-  let () = loop := hrec in
-  hrec
-
-(* Basic hashcons modules for string and obj. Integers do not need be
-   hashconsed.  *)
-
-module type HashedType = sig type t val hash : t -> int end
-
-(* list *)
-module Hlist (D:HashedType) =
-  Make(
-    struct
-      type t = D.t list
-      type u = (t -> t) * (D.t -> D.t)
-      let hashcons (hrec,hdata) = function
-        | x :: l -> hdata x :: hrec l
-        | l -> l
-      let eq l1 l2 =
-        l1 == l2 ||
-          match l1, l2 with
-          | [], [] -> true
-          | x1::l1, x2::l2 -> x1==x2 && l1==l2
-          | _ -> false
-      let rec hash accu = function
-      | [] -> accu
-      | x :: l ->
-        let accu = Hashset.Combine.combine (D.hash x) accu in
-        hash accu l
-      let hash l = hash 0 l
-    end)
-
-(* string *)
-module Hstring = Make(
-  struct
-    type t = string
-    type u = unit
-    let hashcons () s =(* incr accesstr;*) s
-    external eq : string -> string -> bool = "caml_string_equal" "noalloc"
-    (** Copy from CString *)
-    let rec hash len s i accu =
-      if i = len then accu
-      else
-        let c = Char.code (String.unsafe_get s i) in
-        hash len s (succ i) (accu * 19 + c)
-
-    let hash s =
-      let len = String.length s in
-      hash len s 0 0
-  end)
-
-(* Obj.t *)
-exception NotEq
-
-(* From CAMLLIB/caml/mlvalues.h *)
-let no_scan_tag = 251
-let tuple_p obj = Obj.is_block obj && (Obj.tag obj < no_scan_tag)
-
-let comp_obj o1 o2 =
-  if tuple_p o1 && tuple_p o2 then
-    let n1 = Obj.size o1 and n2 = Obj.size o2 in
-      if n1=n2 then
-        try
-          for i = 0 to pred n1 do
-            if not (Obj.field o1 i == Obj.field o2 i) then raise NotEq
-          done; true
-        with NotEq -> false
-      else false
-  else o1=o2
-
-let hash_obj hrec o =
-  begin
-    if tuple_p o then
-      let n = Obj.size o in
-        for i = 0 to pred n do
-          Obj.set_field o i (hrec (Obj.field o i))
-        done
-  end;
-  o
-
-module Hobj = Make(
-  struct
-    type t = Obj.t
-    type u = (Obj.t -> Obj.t) * unit
-    let hashcons (hrec,_) = hash_obj hrec
-    let eq = comp_obj
-    let hash = Hashtbl.hash
-  end)
-- 
cgit v1.2.3