Module Kappa_data_structures.Bigbuffer

Extensible buffers.

This module implements 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 bigstring = (char, Stdlib.Bigarray.int8_unsigned_elt, Stdlib.Bigarray.c_layout) Stdlib.Bigarray.Array1.t
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 byte sequence that holds the buffer contents. That byte sequence 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 -> bigstring

Return a copy of the current contents of the buffer. The buffer itself is unchanged.

val add_char : t -> char -> unit

add_char b c appends the character c at the end of buffer b.

val length : t -> int

Return the number of characters currently contained in the buffer.

val add_string : t -> string -> unit

add_string b s appends the string s at the end of 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 buffer b.

val add_subbytes : t -> bytes -> int -> int -> unit

add_subbytes b s ofs len takes len characters from offset ofs in byte sequence s and appends them at the end of buffer b.

  • since 4.02
val nth : t -> int -> char

Get the n-th character of the buffer. Raise Invalid_argument if index out of bounds

val clear : t -> unit

Empty the buffer.

val reset : t -> unit

Empty the buffer and deallocate the internal byte sequence holding the buffer contents, replacing it with the initial internal byte sequence 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.