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(*                                                                     *)
(*                           Objective Caml                            *)
(*                                                                     *)
(*  Pierre Weis and Xavier Leroy, projet Cristal, INRIA Rocquencourt   *)
(*                                                                     *)
(*  Copyright 1999 Institut National de Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed    *)
(*  under the terms of the GNU Library General Public License.         *)
(*                                                                     *)
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(* Module [Buffer]: extensible string buffers *)

(* This module implements string buffers that automatically expand
   as necessary.  It provides accumulative concatenation of strings
   in quasi-linear time (instead of quadratic time when strings are
   concatenated pairwise). *)

type t
     (* The abstract type of buffers. *)

val create : int -> t
     (* [create n] returns a fresh buffer, initially empty.
        The [n] parameter is the initial size of the internal string
        that holds the buffer contents.  That string is automatically
        reallocated when more than [n] characters are stored in the buffer,
        but shrinks back to [n] characters when [reset] is called.
        For best performance, [n] should be of the same order of magnitude
        as the number of characters that are expected to be stored in
        the buffer (for instance, 80 for a buffer that holds one output
        line).  Nothing bad will happen if the buffer grows beyond that
        limit, however.  In doubt, take [n = 16] for instance.
        If [n] is not between 1 and [Sys.max_string_length], it will
        be clipped to that interval. *)
val contents : t -> string
     (* Return a copy of the current contents of the buffer.
        The buffer itself is unchanged. *)
val length : t -> int
     (* Return the number of characters currently contained in the buffer. *)
val clear : t -> unit
     (* Empty the buffer. *)
val reset : t -> unit
     (* Empty the buffer and deallocate the internal string holding the
        buffer contents, replacing it with the initial internal string
        of length [n] that was allocated by [create n].
        For long-lived buffers that may have grown a lot, [reset] allows
        faster reclaimation of the space used by the buffer. *)
val add_char : t -> char -> unit
     (* [add_char b c] appends the character [c] at the end of
        the buffer [b]. *)
val add_string : t -> string -> unit
     (* [add_string b s] appends the string [s] at the end of
        the buffer [b]. *)
val add_substring : t -> string -> pos:int -> len:int -> unit
     (* [add_substring b s ofs len] takes [len] characters from offset
        [ofs] in string [s] and appends them at the end of the buffer [b]. *)
val add_buffer : t -> src:t -> unit
     (* [add_buffer b1 b2] appends the current contents of buffer [b2]
        at the end of buffer [b1].  [b2] is not modified. *)
val add_channel : t -> in_channel -> len:int -> unit
     (* [add_channel b ic n] reads exactly [n] character from the
        input channel [ic] and stores them at the end of buffer [b].
        Raise [End_of_file] if the channel contains fewer than [n]
        characters. *)
val output_buffer : to:out_channel -> t -> unit
     (* [output_buffer oc b] writes the current contents of buffer [b]
        on the output channel [oc]. *)