summaryrefslogtreecommitdiff
path: root/lib/hashtbl_alt.mli
diff options
context:
space:
mode:
authorGravatar Stephane Glondu <steph@glondu.net>2012-01-12 16:04:54 +0100
committerGravatar Stephane Glondu <steph@glondu.net>2012-01-12 16:04:54 +0100
commit39efc41237ec906226a3a53d7396d51173495204 (patch)
tree87cd58d72d43469d2a2a0a127c1060d7c9e0206b /lib/hashtbl_alt.mli
parent5fe4ac437bed43547b3695664974f492b55cb553 (diff)
parent97fefe1fcca363a1317e066e7f4b99b9c1e9987b (diff)
Remove non-DFSG contentsupstream/8.4_beta+dfsg
Diffstat (limited to 'lib/hashtbl_alt.mli')
-rw-r--r--lib/hashtbl_alt.mli41
1 files changed, 41 insertions, 0 deletions
diff --git a/lib/hashtbl_alt.mli b/lib/hashtbl_alt.mli
new file mode 100644
index 00000000..a22dbc28
--- /dev/null
+++ b/lib/hashtbl_alt.mli
@@ -0,0 +1,41 @@
+(************************************************************************)
+(* v * The Coq Proof Assistant / The Coq Development Team *)
+(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2010 *)
+(* \VV/ **************************************************************)
+(* // * This file is distributed under the terms of the *)
+(* * GNU Lesser General Public License Version 2.1 *)
+(************************************************************************)
+
+(* The following module is a specialized version of [Hashtbl] that is
+ a better space saver. Actually, [Hashcons] instanciates [Hashtbl.t]
+ with [constr] used both as a key and as an image. Thus, in each
+ cell of the internal bucketlist, there are two representations of
+ the same value. In this implementation, there is only one.
+
+ Besides, the responsibility of computing the hash function is now
+ given to the caller, which makes possible the interleaving of the
+ hash key computation and the hash-consing. *)
+
+module type Hashtype = sig
+ type t
+ val equals : t -> t -> bool
+end
+
+module type S = sig
+ type elt
+ (* [may_add_and_get key constr] uses [key] to look for [constr]
+ in the hash table [H]. If [constr] is in [H], returns the
+ specific representation that is stored in [H]. Otherwise,
+ [constr] is stored in [H] and will be used as the canonical
+ representation of this value in the future. *)
+ val may_add_and_get : int -> elt -> elt
+end
+
+module Make (E : Hashtype) : S with type elt = E.t
+
+module Combine : sig
+ val combine : int -> int -> int
+ val combinesmall : int -> int -> int
+ val combine3 : int -> int -> int -> int
+ val combine4 : int -> int -> int -> int -> int
+end