clr.tools.nrepl

A port of babashka/babashka.nrepl library to ClojureCLR.

A shoutout to Michiel Borkent (@borkdude) for writing the original and for assistance in getting this port up and running.

There is a work-in-progress port of nrepl/nrepl. That is in down in subdirectory partial-nrepl-nrepl-port. Go for it.

Status

We are in alpha for the first release. The original test suite passes. We are starting work to test against nREPL clients (think of Calva, CIDER).

Usage

The original babashka.nrepl was build to to run under SCI. (See https://github.com/babashka/sci.) This port has nothing to do with SCI.
Otherwise the usage is similar to the original. We reproduce those notes here with appropriate modifications.

The original version needed a SCI context passed in to start-server!.
We have maintained that parameter for now -- we will be passing in an empty map -- until we can assess possible need for it in our context.
This aspect of the interface may change as we continue with the alpha development.

Starting a server

To start an nREPL server, call clojure.tools.nrepl/start-server!. The call takes one optional argumen, a server options map.

(clojure.tools.nrepl/start-server! {:host "127.0.0.1" :port 12345})

Option keys include:

• :debug -- if set to true, the nREPL server will print to standard output all the messages it is receiving over the nREPL channel.
• :debug-send -- if set to true, the server will also print the messages it is sending
• :quiet -- if set to true the nREPL server will not print out the message "starting nREPL server at ..." when starting.
  Note that some clients (CIDER?) require this message in order pick up information such as the port number, or so I've heard. If not specified, :quiet defatuls to false, and the message will be printed.
• :port -- the port number. If not specified, defaults to 1667.
• :host -- the host IP address or DNS name. If not specified, it defaults to 0.0.0.0. (Bind to every interface.)
• :xform -- if not specified, defatuls to clojure.core.nrepl.middleware/default-xform.
  See the babashka.nrepl middleware docs for more information.

If no options hashmap is specifed at all, all the defaults will be used. Thus you can start the nREPL server minimally with

(clojure.tools.nrepl/start-server!)

Stopping a server

Pass the result returned from start-server! to stop-server!:

(def server (clojure.tools.nrepl/start-server!))
....

(clojure.tools.nrepl/stop-server! server)

Parsing an nREPL options string

Use clojure.tools.nrepl/parse-opt to parse a hostname:port string into a map to pass to start-server!:

(clojure.tools.nrepl/start-server! {} (clojure.tools.nrepl/parse-opt "localhost:12345"))

Middleware

The nREPL middleware is customizable. Also this is untested. We will be following the babashka.nrepl middleware docs.

There is a rumor that the middleware design may change in the future.

Releases

clj dependency information:

io.github.clojure/clr.tools.reader {:git/tag "v0.1.0-alpha2" :git/sha "a58009f"}

PM> Install-Package clojure.tools.nrepl -Version 0.1.0-alpha2

Leiningen/Clojars reference:

[org.clojure.clr/tools.nrepl "0.1.0-alpha2]

Copyright and License

The babashka.nrepl code had the following:

The project code is Copyright © 2019-2023 Michiel Borkent

It is distributed under the Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)