130 lines
5.6 KiB
OCaml
130 lines
5.6 KiB
OCaml
(***********************************************************************)
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(* *)
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(* OCaml *)
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(* *)
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(* Pierre Weis and Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1999 Institut National de Recherche en Informatique et *)
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(* en Automatique. All rights reserved. This file is distributed *)
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(* under the terms of the GNU Library General Public License, with *)
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(* the special exception on linking described in file ../LICENSE. *)
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(* *)
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(***********************************************************************)
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(** Extensible buffers.
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This module implements buffers that automatically expand
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as necessary. It provides accumulative concatenation of strings
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in quasi-linear time (instead of quadratic time when strings are
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concatenated pairwise).
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*)
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type t
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(** The abstract type of buffers. *)
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val create : int -> t
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(** [create n] returns a fresh buffer, initially empty.
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The [n] parameter is the initial size of the internal byte sequence
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that holds the buffer contents. That byte sequence is automatically
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reallocated when more than [n] characters are stored in the buffer,
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but shrinks back to [n] characters when [reset] is called.
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For best performance, [n] should be of the same order of magnitude
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as the number of characters that are expected to be stored in
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the buffer (for instance, 80 for a buffer that holds one output
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line). Nothing bad will happen if the buffer grows beyond that
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limit, however. In doubt, take [n = 16] for instance.
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If [n] is not between 1 and {!Sys.max_string_length}, it will
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be clipped to that interval. *)
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val contents : t -> string
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(** Return a copy of the current contents of the buffer.
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The buffer itself is unchanged. *)
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val to_bytes : t -> bytes
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(** Return a copy of the current contents of the buffer.
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The buffer itself is unchanged.
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@since 4.02 *)
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val sub : t -> int -> int -> string
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(** [Buffer.sub b off len] returns (a copy of) the bytes from the
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current contents of the buffer [b] starting at offset [off] of
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length [len] bytes. May raise [Invalid_argument] if out of bounds
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request. The buffer itself is unaffected. *)
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val blit : t -> int -> bytes -> int -> int -> unit
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(** [Buffer.blit src srcoff dst dstoff len] copies [len] characters from
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the current contents of the buffer [src], starting at offset [srcoff]
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to [dst], starting at character [dstoff].
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Raise [Invalid_argument] if [srcoff] and [len] do not designate a valid
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range of [src], or if [dstoff] and [len] do not designate a valid
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range of [dst].
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@since 3.11.2
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*)
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val nth : t -> int -> char
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(** get the n-th character of the buffer. Raise [Invalid_argument] if
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index out of bounds *)
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val length : t -> int
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(** Return the number of characters currently contained in the buffer. *)
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val clear : t -> unit
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(** Empty the buffer. *)
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val reset : t -> unit
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(** Empty the buffer and deallocate the internal byte sequence holding the
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buffer contents, replacing it with the initial internal byte sequence
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of length [n] that was allocated by {!Buffer.create} [n].
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For long-lived buffers that may have grown a lot, [reset] allows
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faster reclamation of the space used by the buffer. *)
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val add_char : t -> char -> unit
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(** [add_char b c] appends the character [c] at the end of the buffer [b]. *)
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val add_string : t -> string -> unit
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(** [add_string b s] appends the string [s] at the end of the buffer [b]. *)
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val add_bytes : t -> bytes -> unit
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(** [add_string b s] appends the string [s] at the end of the buffer [b].
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@since 4.02 *)
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val add_substring : t -> string -> int -> int -> unit
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(** [add_substring b s ofs len] takes [len] characters from offset
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[ofs] in string [s] and appends them at the end of the buffer [b]. *)
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val add_subbytes : t -> bytes -> int -> int -> unit
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(** [add_substring b s ofs len] takes [len] characters from offset
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[ofs] in byte sequence [s] and appends them at the end of the buffer [b].
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@since 4.02 *)
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val add_substitute : t -> (string -> string) -> string -> unit
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(** [add_substitute b f s] appends the string pattern [s] at the end
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of the buffer [b] with substitution.
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The substitution process looks for variables into
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the pattern and substitutes each variable name by its value, as
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obtained by applying the mapping [f] to the variable name. Inside the
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string pattern, a variable name immediately follows a non-escaped
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[$] character and is one of the following:
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- a non empty sequence of alphanumeric or [_] characters,
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- an arbitrary sequence of characters enclosed by a pair of
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matching parentheses or curly brackets.
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An escaped [$] character is a [$] that immediately follows a backslash
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character; it then stands for a plain [$].
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Raise [Not_found] if the closing character of a parenthesized variable
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cannot be found. *)
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val add_buffer : t -> t -> unit
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(** [add_buffer b1 b2] appends the current contents of buffer [b2]
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at the end of buffer [b1]. [b2] is not modified. *)
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val add_channel : t -> in_channel -> int -> unit
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(** [add_channel b ic n] reads exactly [n] character from the
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input channel [ic] and stores them at the end of buffer [b].
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Raise [End_of_file] if the channel contains fewer than [n]
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characters. *)
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val output_buffer : out_channel -> t -> unit
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(** [output_buffer oc b] writes the current contents of buffer [b]
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on the output channel [oc]. *)
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