circular lists

_oasis

@@ -41,7 +41,7 @@ Library "containers"
                     UnionFind, SmallSet, Leftistheap, AbsSet, CSM, MultiMap,
                     ActionMan, BV, QCheck, BencodeOnDisk, Show, TTree,
                     HGraph, Automaton, Conv, Levenshtein, Bidir, Iteratee,
-                    Ty, Tell, BencodeStream, RatTerm, Cause, KMP
+                    Ty, Tell, BencodeStream, RatTerm, Cause, KMP, CircList
   BuildDepends:     unix
 
 Library "containers_thread"

_tags

@@ -1,5 +1,5 @@
 # OASIS_START
-# DO NOT EDIT (digest: 13877dc814f0b2dee886bafc27842dfc)
+# DO NOT EDIT (digest: e6a4388a1190cdbd6a00960fb2e08d7f)
 # Ignore VCS directories, you can use the same kind of rule outside
 # OASIS_START/STOP if you want to exclude directories that contains
 # useless stuff for the build process
@@ -63,6 +63,7 @@
 "ratTerm.cmx": for-pack(Containers)
 "cause.cmx": for-pack(Containers)
 "KMP.cmx": for-pack(Containers)
+"circList.cmx": for-pack(Containers)
 # Library containers_thread
 "threads/containers_thread.cmxs": use_containers_thread
 <threads/*.ml{,i}>: package(threads)

circList.ml

@@ -0,0 +1,114 @@
+
+(*
+copyright (c) 2013-2014, simon cruanes
+all rights reserved.
+
+redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.  redistributions in binary
+form must reproduce the above copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other materials provided with
+the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*)
+
+(** {1 Functional Circular List}
+
+Those are infinite lists that are built from a finite list of
+elements, and cycles through them. *)
+
+type 'a t = {
+  front : 'a list;
+  f_len : int;
+  rear : 'a list;
+  r_len : int;
+}
+(* invariant: if front=[] then rear=[] *)
+
+let make f f_len r r_len = match f with
+  | [] ->
+      assert (f_len = 0);
+      { front=List.rev r; f_len=r_len; rear=[]; r_len=0; }
+  | _::_ -> {front=f; f_len; rear=r; r_len; }
+
+let singleton x = make [x] 1 [] 0
+
+let of_list l = make l (List.length l) [] 0
+
+let length l = l.f_len + l.r_len
+
+let cons x l = make (x::l.front) (l.f_len+1) l.rear l.r_len
+
+let snoc l x = make l.front l.f_len (x::l.rear) (l.r_len+1)
+
+let next l = match l.front with
+  | [] -> assert false
+  | x::l' ->
+      x, make l' (l.f_len-1) l.rear l.r_len
+
+let rev l = make l.rear l.r_len l.front l.f_len
+
+let find p l =
+  let rec _find p i l =
+    if i = 0 then None
+    else
+      let x, l' = next l in
+      if p x then Some x else _find p (i-1) l'
+  in
+  _find p (length l) l
+
+let mem ?(eq=fun x y -> x=y) x l =
+  match find (eq x) l with
+  | None -> false
+  | Some _ -> true
+
+let exists p l = match find p l with
+  | None -> false
+  | Some _ -> true
+
+let for_all p l =
+  let rec _check i l =
+    i = 0 ||
+    ( let x, l' = next l in
+      p x && _check (i-1) l')
+  in
+  _check (length l) l
+
+let fold f acc l =
+  let rec _fold acc i l =
+    if i=0 then acc
+    else
+      let x, l' = next l in
+      let acc = f acc x in
+      _fold acc (i-1) l'
+  in
+  _fold acc (length l) l
+
+type 'a gen = unit -> 'a option
+type 'a sequence = ('a -> unit) -> unit
+
+let gen l =
+  let l = ref l in
+  fun () ->
+    let x, l' = next !l in
+    l := l';
+    Some x
+
+let seq l k =
+  let r' = lazy (List.rev l.rear) in
+  while true do
+    List.iter k l.front;
+    List.iter k (Lazy.force r')
+  done

circList.mli

@@ -0,0 +1,81 @@
+
+(*
+copyright (c) 2013-2014, simon cruanes
+all rights reserved.
+
+redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.  redistributions in binary
+form must reproduce the above copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other materials provided with
+the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*)
+
+(** {1 Functional Circular List}
+
+Those are infinite lists that are built from a finite list of
+elements, and cycles through them.
+Unless specified otherwise, operations have an amortized cost in O(1). *)
+
+type +'a t
+
+val singleton : 'a -> 'a t
+(** list that cycles on one element *)
+
+val of_list : 'a list -> 'a t
+(** build a circular list from a list. Linear in the length
+    of the list *)
+
+val length : 'a t -> int
+(** length of the cycle. *)
+
+val cons : 'a -> 'a t -> 'a t
+(** [cons x l] adds [x] at the beginning of [l] *)
+
+val snoc : 'a t -> 'a -> 'a t
+(** [snoc l x] adds [x] at the end of [l] *)
+
+val next : 'a t -> 'a * 'a t
+(** obtain the next element, and the list rotated by one. *)
+
+val rev : 'a t -> 'a t
+(** reverse the traversal (goes right-to-left from now). *)
+
+val find : ('a -> bool) -> 'a t -> 'a option
+(** [find p l] returns [Some x] where [p x] is [true]
+    and [x] belongs to [l], or [None] if no such
+    element exists *)
+
+val mem : ?eq:('a -> 'a -> bool) -> 'a -> 'a t -> bool
+(** does the element belong to the infinite list? *)
+
+val exists : ('a -> bool) -> 'a t -> bool
+
+val for_all : ('a -> bool) -> 'a t -> bool
+
+val fold : ('b -> 'a -> 'b) -> 'b -> 'a t -> 'b
+(** fold through each element of the list exactly once. *)
+
+(** {2 Iterators} *)
+
+type 'a gen = unit -> 'a option
+type 'a sequence = ('a -> unit) -> unit
+
+val gen : 'a t -> 'a gen
+(** Generator on elements of the list *)
+
+val seq : 'a t -> 'a sequence
+(** Sequence of elements of the list *)

containers.mlpack

@@ -1,5 +1,5 @@
 # OASIS_START
-# DO NOT EDIT (digest: 404fe51c40218ed7bf430446cec5efde)
+# DO NOT EDIT (digest: 157f88a0bbe94188791880b268b7df2a)
 Cache
 Deque
 Gen
@@ -48,4 +48,5 @@ BencodeStream
 RatTerm
 Cause
 KMP
+CircList
 # OASIS_STOP

containers.odocl

@@ -1,5 +1,5 @@
 # OASIS_START
-# DO NOT EDIT (digest: 404fe51c40218ed7bf430446cec5efde)
+# DO NOT EDIT (digest: 157f88a0bbe94188791880b268b7df2a)
 Cache
 Deque
 Gen
@@ -48,4 +48,5 @@ BencodeStream
 RatTerm
 Cause
 KMP
+CircList
 # OASIS_STOP

setup.ml

@@ -1,7 +1,7 @@
 (* setup.ml generated for the first time by OASIS v0.3.0 *)
 
 (* OASIS_START *)
-(* DO NOT EDIT (digest: b545212f57a5e5b473eeea4866484af0) *)
+(* DO NOT EDIT (digest: 6abff81b4f6ff21a732c0e62491fa464) *)
 (*
    Regenerated by OASIS v0.4.4
    Visit http://oasis.forge.ocamlcore.org for more information and
@@ -7006,7 +7006,8 @@ let setup_t =
                            "BencodeStream";
                            "RatTerm";
                            "Cause";
-                           "KMP"
+                           "KMP";
+                           "CircList"
                         ];
                       lib_pack = true;
                       lib_internal_modules = [];
@@ -7393,7 +7394,7 @@ let setup_t =
        };
      oasis_fn = Some "_oasis";
      oasis_version = "0.4.4";
-     oasis_digest = Some "\228\227\"@\138\216\007\132\190[\139\215a\153B<";
+     oasis_digest = Some "\174j\228\162\204\138v>\191a1\251\130\209\232\003";
      oasis_exec = None;
      oasis_setup_args = [];
      setup_update = false
@@ -7401,6 +7402,6 @@ let setup_t =
 
 let setup () = BaseSetup.setup setup_t;;
 
-# 7405 "setup.ml"
+# 7406 "setup.ml"
 (* OASIS_STOP *)
 let () = setup ();;