src/Tools/Metis/src/Stream.sig

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Tools/Metis/src/Stream.sig	Mon Sep 13 21:09:43 2010 +0200
@@ -0,0 +1,109 @@
+(* ========================================================================= *)
+(* A POSSIBLY-INFINITE STREAM DATATYPE FOR ML                                *)
+(* Copyright (c) 2001-2006 Joe Hurd, distributed under the GNU GPL version 2 *)
+(* ========================================================================= *)
+
+signature Stream =
+sig
+
+(* ------------------------------------------------------------------------- *)
+(* The stream type.                                                          *)
+(* ------------------------------------------------------------------------- *)
+
+datatype 'a stream = Nil | Cons of 'a * (unit -> 'a stream)
+
+(* If you're wondering how to create an infinite stream: *)
+(* val stream4 = let fun s4 () = Stream.Cons (4,s4) in s4 () end; *)
+
+(* ------------------------------------------------------------------------- *)
+(* Stream constructors.                                                      *)
+(* ------------------------------------------------------------------------- *)
+
+val repeat : 'a -> 'a stream
+
+val count : int -> int stream
+
+val funpows : ('a -> 'a) -> 'a -> 'a stream
+
+(* ------------------------------------------------------------------------- *)
+(* Stream versions of standard list operations: these should all terminate.  *)
+(* ------------------------------------------------------------------------- *)
+
+val cons : 'a -> (unit -> 'a stream) -> 'a stream
+
+val null : 'a stream -> bool
+
+val hd : 'a stream -> 'a  (* raises Empty *)
+
+val tl : 'a stream -> 'a stream  (* raises Empty *)
+
+val hdTl : 'a stream -> 'a * 'a stream  (* raises Empty *)
+
+val singleton : 'a -> 'a stream
+
+val append : 'a stream -> (unit -> 'a stream) -> 'a stream
+
+val map : ('a -> 'b) -> 'a stream -> 'b stream
+
+val maps :
+    ('a -> 's -> 'b * 's) -> ('s -> 'b stream) -> 's -> 'a stream -> 'b stream
+
+val zipwith : ('a -> 'b -> 'c) -> 'a stream -> 'b stream -> 'c stream
+
+val zip : 'a stream -> 'b stream -> ('a * 'b) stream
+
+val take : int -> 'a stream -> 'a stream  (* raises Subscript *)
+
+val drop : int -> 'a stream -> 'a stream  (* raises Subscript *)
+
+(* ------------------------------------------------------------------------- *)
+(* Stream versions of standard list operations: these might not terminate.   *)
+(* ------------------------------------------------------------------------- *)
+
+val length : 'a stream -> int
+
+val exists : ('a -> bool) -> 'a stream -> bool
+
+val all : ('a -> bool) -> 'a stream -> bool
+
+val filter : ('a -> bool) -> 'a stream -> 'a stream
+
+val foldl : ('a * 's -> 's) -> 's -> 'a stream -> 's
+
+val concat : 'a stream stream -> 'a stream
+
+val mapPartial : ('a -> 'b option) -> 'a stream -> 'b stream
+
+val mapsPartial :
+    ('a -> 's -> 'b option * 's) -> ('s -> 'b stream) -> 's ->
+    'a stream -> 'b stream
+
+val mapConcat : ('a -> 'b stream) -> 'a stream -> 'b stream
+
+val mapsConcat :
+    ('a -> 's -> 'b stream * 's) -> ('s -> 'b stream) -> 's ->
+    'a stream -> 'b stream
+
+(* ------------------------------------------------------------------------- *)
+(* Stream operations.                                                        *)
+(* ------------------------------------------------------------------------- *)
+
+val memoize : 'a stream -> 'a stream
+
+val listConcat : 'a list stream -> 'a stream
+
+val concatList : 'a stream list -> 'a stream
+
+val toList : 'a stream -> 'a list
+
+val fromList : 'a list -> 'a stream
+
+val toString : char stream -> string
+
+val fromString : string -> char stream
+
+val toTextFile : {filename : string} -> string stream -> unit
+
+val fromTextFile : {filename : string} -> string stream  (* line by line *)
+
+end