116 lines
5.1 KiB
OCaml
116 lines
5.1 KiB
OCaml
(***********************************************************************)
|
|
(* *)
|
|
(* 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, with *)
|
|
(* the special exception on linking described in file ../LICENSE. *)
|
|
(* *)
|
|
(***********************************************************************)
|
|
|
|
(* $Id$ *)
|
|
|
|
(** 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 sub : t -> int -> int -> string
|
|
(** [Buffer.sub b off len] returns (a copy of) the substring of the
|
|
current contents of the buffer [b] starting at offset [off] of length
|
|
[len] bytes. May raise [Invalid_argument] if out of bounds request. The
|
|
buffer itself is unaffected. *)
|
|
|
|
val blit : t -> int -> string -> int -> int -> unit
|
|
(** [Buffer.blit src srcoff dst dstoff len] copies [len] characters from
|
|
the current contents of the buffer [src], starting at offset [srcoff]
|
|
to string [dst], starting at character [dstoff].
|
|
|
|
Raise [Invalid_argument] if [srcoff] and [len] do not designate a valid
|
|
substring of [src], or if [dstoff] and [len] do not designate a valid
|
|
substring of [dst]. *)
|
|
|
|
val nth : t -> int -> char
|
|
(** get the n-th character of the buffer. Raise [Invalid_argument] if
|
|
index out of bounds *)
|
|
|
|
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 {!Buffer.create} [n].
|
|
For long-lived buffers that may have grown a lot, [reset] allows
|
|
faster reclamation 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 -> int -> 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_substitute : t -> (string -> string) -> string -> unit
|
|
(** [add_substitute b f s] appends the string pattern [s] at the end
|
|
of the buffer [b] with substitution.
|
|
The substitution process looks for variables into
|
|
the pattern and substitutes each variable name by its value, as
|
|
obtained by applying the mapping [f] to the variable name. Inside the
|
|
string pattern, a variable name immediately follows a non-escaped
|
|
[$] character and is one of the following:
|
|
- a non empty sequence of alphanumeric or [_] characters,
|
|
- an arbitrary sequence of characters enclosed by a pair of
|
|
matching parentheses or curly brackets.
|
|
An escaped [$] character is a [$] that immediately follows a backslash
|
|
character; it then stands for a plain [$].
|
|
Raise [Not_found] if the closing character of a parenthesized variable
|
|
cannot be found. *)
|
|
|
|
val add_buffer : t -> 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 -> 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 : out_channel -> t -> unit
|
|
(** [output_buffer oc b] writes the current contents of buffer [b]
|
|
on the output channel [oc]. *)
|