From a24d1a15858df9574e491bf952a59e700cc75ecc Mon Sep 17 00:00:00 2001
From: Hugo Herbelin
Date: Mon, 5 Apr 2021 16:23:35 +0200
Subject: LStream: a library for streams with non-canonical locations.

---
 lib/lStream.mli | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 lib/lStream.mli

(limited to 'lib/lStream.mli')

diff --git a/lib/lStream.mli b/lib/lStream.mli
new file mode 100644
index 0000000000..fc9b5b5ce1
--- /dev/null
+++ b/lib/lStream.mli
@@ -0,0 +1,55 @@
+(************************************************************************)
+(*         *   The Coq Proof Assistant / The Coq Development Team       *)
+(*  v      *         Copyright INRIA, CNRS and contributors             *)
+(* <O___,, * (see version control and CREDITS file for authors & dates) *)
+(*   \VV/  **************************************************************)
+(*    //   *    This file is distributed under the terms of the         *)
+(*         *     GNU Lesser General Public License Version 2.1          *)
+(*         *     (see LICENSE file for the text of the license)         *)
+(************************************************************************)
+
+(** Extending streams with a (non-canonical) location function *)
+
+type 'a t
+val from : ?source:Loc.source -> (int -> ('a * Loc.t) option) -> 'a t
+
+(** Returning the loc of the last consumed element or the initial loc
+    if no element is consumed *)
+val current_loc : 'a t -> Loc.t
+
+(** Returning the loc of the max visited element or the initial loc
+    if no element is consumed *)
+val max_peek_loc : 'a t -> Loc.t
+
+(** Returning the loc starting after element [bp] (counting from 0)
+    and spanning up to already peeked element at position [ep], under
+    the assumption that [bp] <= [ep]; returns an empty interval if
+    [bp] = [ep]; returns the empty initial interval if additionally
+    [bp] = 0; fails if the elements have not been peeked yet *)
+val interval_loc : int -> int -> 'a t -> Loc.t
+
+(** Return location of an already peeked element at some position counting from 0;
+    fails if the element has not been peeked yet *)
+val get_loc : int -> 'a t -> Loc.t
+
+(** Lifted usual function on streams *)
+
+val count : 'a t -> int
+
+val peek : 'a t -> 'a option
+
+val npeek : int -> 'a t -> 'a list
+
+val junk : 'a t -> unit
+  (** consumes the next element if there is one *)
+
+val next : 'a t -> 'a
+  (** [next strm] returns and consumes the next element;
+      raise [Stream.Failure] if the stream is empty *)
+
+(** Other functions *)
+
+val peek_nth : int -> 'a t -> 'a
+  (** [peek_nth n strm] returns the nth element counting from 0 without
+      consuming the stream; raises [Stream.Failure] if not enough
+      elements *)
-- 
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