bufio

Generic buffered I/O for Carp.

Installation

(load "git@github.com:carpentry-org/bufio@0.1.0")

Usage

BufReader wraps any stream that implements the stream-read and stream-write interfaces, providing buffered line-oriented and size-delimited reading, and buffered writing.

With TCP sockets

The socket library implements the interfaces for TcpStream:

(match (TcpStream.connect "example.com" 80)
  (Result.Success s)
    (let [br (TcpStream.buffered s)]
      (do
        (BufReader.write &br "GET / HTTP/1.0\r\nHost: example.com\r\n\r\n")
        (ignore (BufReader.flush &br))
        (match (BufReader.read-line &br)
          (Result.Success line) (println* &line)
          (Result.Error e) (IO.errorln &e))
        (BufReader.delete br)))
  (Result.Error e) (IO.errorln &e))

Implementing for your own types

Define three interface functions for your stream type:

; stream-read: read up to `len` bytes into buf, return bytes read
(definterface stream-read (Fn [&a &(Array Byte) Int] Int))

; stream-write: write bytes, return bytes written
(definterface stream-write (Fn [&a &(Array Byte)] Int))

; stream-close: close the stream
(definterface stream-close (Fn [a] ()))

Then provide a buffered function that creates a BufReader via the C-level BufReader_create_ with your type's adapter function pointers.

API

• BufReader.read-line — read until \n
• BufReader.read-until — read until a delimiter byte
• BufReader.read-n — read exactly N bytes
• BufReader.read-append — append read data to a byte buffer
• BufReader.write — buffer string data
• BufReader.write-bytes — buffer binary data
• BufReader.flush — send buffered writes
• BufReader.clear-read / BufReader.clear-write — discard buffers
• BufReader.delete — close underlying stream and free buffers

Testing

carp -x test/bufio.carp

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Have fun!