# uni-channel

`uni-channel` provides one simple wrapper over `async-channel`, `place-channel`
and `port-channel`.

```racket
(make-uni-channel channel)
```

The constructor detects the concrete channel kind and returns a `uni-channel?`.
No helper constructors are part of the public API; create the underlying channel
with the normal Racket or `port-channel` constructor and then wrap it.

A wrapped channel that can receive is itself synchronizable. `(sync ch)` returns
the value received from the underlying channel. For an output-only endpoint, such
as an output `port-channel`, the receive event is `never-evt` because no value can
be received from that endpoint.


```racket
(require racket/async-channel
         uni-channel)

(define ch (make-uni-channel (make-async-channel)))
(uni-channel-send ch 'hello)
(uni-channel-recv ch)
```

For `port-channel`, wrap the input and output endpoints separately:

```racket
(require port-channel
         uni-channel)

(define-values (in out) (make-pipe))
(define reader (make-uni-channel (make-port-channel in)))
(define writer (make-uni-channel (make-port-channel out)))

(uni-channel-send writer '(hello 1 2 3))
(uni-channel-recv reader)
```

For output port-channels, `uni-channel-put` queues the value for the writer
thread. Use `uni-channel-close` followed by `uni-channel-wait` when shutdown must
wait until queued values have actually been written and the writer thread has
stopped.

Install and test:

```sh
raco pkg install --auto port-channel
raco pkg install --auto ./uni-channel
raco test -x -p uni-channel
raco setup --pkgs uni-channel
```