[lib] Split auxiliary libraries into Coq-specific and general.

Up to this point the `lib` directory contained two different library
archives, `clib.cma` and `lib.cma`, which a rough splitting between
Coq-specific libraries and general-purpose ones.

We know split the directory in two, as to make the distinction clear:

- `clib`: contains libraries that are not Coq specific and implement
  common data structures and programming patterns. These libraries
  could be eventually replace with external dependencies and the rest
  of the code base wouldn't notice much.

- `lib`: contains Coq-specific common libraries in widespread use
  along the codebase, but that are not considered part of other
  components. Examples are printing, error handling, or flags.

In some cases we have coupling due to utility files depending on Coq
specific flags, however this commit doesn't modify any files, but only
moves them around, further cleanup is welcome, as indeed a few files
in `lib` should likely be placed in `clib`.

Also note that `Deque` is not used ATM.

1 files changed, 56 insertions, 0 deletions

diff --git a/clib/hashset.mli b/clib/hashset.mli
new file mode 100644
index 000000000..ec79205a5
--- /dev/null
+++ b/clib/hashset.mli
@@ -0,0 +1,56 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2017     *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+(** Adapted from Damien Doligez, projet Para, INRIA Rocquencourt,
+    OCaml stdlib. *)
+
+(** The following functor is a specialized version of [Weak.Make].
+    Here, 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 EqType = sig
+  type t
+  val eq : t -> t -> bool
+end
+
+type statistics = {
+  num_bindings: int;
+  num_buckets: int;
+  max_bucket_length: int;
+  bucket_histogram: int array
+}
+
+module type S = sig
+  type elt
+  (** Type of hashsets elements. *)
+  type t
+  (** Type of hashsets. *)
+  val create : int -> t
+  (** [create n] creates a fresh hashset with initial size [n]. *)
+  val clear : t -> unit
+  (** Clear the contents of a hashset. *)
+  val repr : int -> elt -> t -> elt
+  (** [repr key constr set] uses [key] to look for [constr]
+      in the hashet [set]. If [constr] is in [set], returns the
+      specific representation that is stored in [set]. Otherwise,
+      [constr] is stored in [set] and will be used as the canonical
+      representation of this value in the future. *)
+  val stats : t -> statistics
+  (** Recover statistics on the table. *)
+end
+
+module Make (E : EqType) : 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
+  val combine5 : int -> int -> int -> int -> int -> int
+end