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Module Cf_message


module Cf_message: sig .. end
Functional message buffer chains.

Overview

This module implements convenience functions useful when manipulating lists of substrings that represent portable inter-process communication messages. A list of substrings is very much like the "mbuf" chain commonly found in network protocol stacks, and this module facilitates composing and manipulating messages in this way.

Types

type t = (string * int * int) list
The type of messages, i.e. a list of substrings (a string, the position of the first character in the substring, and the length of the substring).

Functions

val normalize : t -> t
Use normalize m to discard empty substrings from the list. Raises Invalid_arg if any of the substrings have a negative length or which specify invalid substrings of the string component of the triple.
val create : string -> t
Use create s to obtain a new message composed of a flattened message containing the string s. Returns the empty list when the string is the empty string.
val length : t -> int
Use length m to compute the length of the message m.
val contents : t -> string
Use contents m to create a new string containing the entire text of the message m.
val copy : t -> t
Use copy m to create a new message with a deep copy of the contents of m, i.e. it is equivalent to create (contents m).
val flatten : t -> t
Use flatten m to reduce a message list of two or more substrings to a single substring. If m is already a single substring or the empty list, then m itself is returned. Otherwise, the result is the same as what copy m would return.
val split : pos:int -> t -> t * t
Use split ~pos m to return two new messages, the first containing all the text in message m before the position pos, and the second containing all the remaining text in message m. The strings themselves are not copied; only the list of substrings is manipulated. Raises Invalid_argument if the position is negative or beyond the length of the message.
val truncate : pos:int -> t -> t
Use truncate ~pos m to return a new message containing all the text in message m before the position pos. The strings themselves are not copied; only the list of substrings is manipulated. Raises Invalid_argument if the position is negative or beyond the length of the message.
val shift : pos:int -> t -> t
Use shift ~pos m to return a new message with all the text in message m before the position pos removed. This strings themselves are not copied; only the list of substrings is manipulated. Raises Invalid_argument if the position is negative or beyond the length of the message.
val insert : pos:int -> m:t -> t -> t
Use insert ~pos ~m m1 to return a new message with all the text in message m inserted into the message m1 at the position pos. The strings themselves are not copied; only the list of substrings is manipulated. Raises Invalid_argument if the position is negative or beyond the length of the message.
val to_seq : t -> char Cf_seq.t
Use to_seq m to obtain the sequence of characters in message m. The message is immediately normalized with normalize m.
val to_seq2 : t -> (char * t) Cf_seq.t
Use to_seq2 m to obtain the sequence of characters in message m with each character associated with the remainder of the message. The message is immediately normalized with normalize m.