ocaml/stdlib/stream.mli

79 lines
3.2 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Daniel de Rauglaudre, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Module [Stream]: streams and stream parsers operations *)
type 'a t
(* The type of streams containing values of type ['a]. *)
exception Parse_failure
(* Raised by parsers when none of the first components of the stream
patterns is accepted. *)
exception Parse_error of string
(* Raised by parsers when the first component of a stream pattern is
accepted, but one of the following components is rejected. *)
(** Stream builders *)
(* Warning: these functions create streams with fast access; it is illegal
to mix them with streams built with [[< >]]; would raise [Failure]
when accessing such mixed streams. *)
val from : (int -> 'a option) -> 'a t
(* [Stream.from f] returns a stream built from the function [f].
To create a new stream element, the function [f] is called with
the current stream count. The user function [f] must return either
[Some <value>] for a value or [None] to specify the end of the
stream. *)
val of_list : 'a list -> 'a t
(* Return the stream holding the elements of the list in the same
order. *)
val of_string : string -> char t
(* Return the stream of the characters of the string parameter. *)
val of_channel : in_channel -> char t
(* Return the stream of the characters read from the input channel. *)
(** Stream iterator *)
val iter : ('a -> 'b) -> 'a t -> unit
(* [Stream.iter f s] scans the whole stream s, applying function [f]
in turn to each stream element encountered. *)
(** Predefined parsers *)
val next : 'a t -> 'a
(* Return the first element of the stream and remove it from the
stream. Raise [Parse_failure] if the stream is empty. *)
val empty : 'a t -> unit
(* Return [()] if the stream is empty, else raise [Parse_failure]. *)
(** Useful functions *)
val peek : 'a t -> 'a option
(* Return [Some c] where [c] is the first element of the stream,
or [None] if the stream is empty. *)
val junk : 'a t -> unit
(* Remove the first element of the stream, possibly unfreezing
it before. *)
val count : 'a t -> int
(* Return the current count of the stream elements, i.e. the number
of the stream elements discarded. *)
(*--*)
(*** For system use only, not for the casual user *)
val sempty : 'a t
val scons : (unit -> 'a) -> 'a t -> 'a t
val sapp : (unit -> 'a t) -> 'a t -> 'a t
val dump : ('a -> unit) -> 'a t -> unit