Asynchronous Reliable Extensible Sleek RPC Server for Guile. First of all it’s a library providing a lot of tools for evaluating and exploring the code, from simple reflection API to interruptible asynchronous evaluation. In addition to that it provides an async RPC server implementation based on nREPL protocol and can be used for programmable interactions with a running guile processes, for implementing REPLs, IDEs, test runners or other tools. It also can be potentially used as a backend or library for LSP server.

guile-ares-rs was previously known as guile-nrepl (because it started as just nREPL implementation in Guile Scheme). It was renamed to avoid any confusion with network/socket REPL, guile-ares-rs is not a usual REPL, it’s actually not a REPL at all, it’s an RPC Server, however it’s possible to implement REPL-like experience with it (and respective client).

It’s intended for use with Arei IDE, but you can use it with other generic nREPL clients.

There are multiple ways to utilize Ares RS, but most straightforward is to spawn a standalone server and connect to it from a client (Emacs Arei for example):

guix shell guile guile-ares-rs -- ares-nrepl

Don’t forget to add your project source code and other dependencies to load path. For example:

ares-nrepl -- -L src/guile

The ares-nrepl command is a wrapper around guile, the above command is equivalent to guile -L src/guile -c '((@ (ares server) run-nrepl-server))'

To be able to use G-expression special syntax #~, #$ and #$@ or when using Arei with Guix or other project, which have reader extensions, load reader extension before starting the nrepl server. You can find the explanation here.

guile -c \
"(begin (use-modules (guix gexp)) #;(load gexp reader extension globally) \
((@ (ares server) run-nrepl-server)))"

To learn more on how to setup a proper environment with exact version of Guix and channels available in the load path, take a look at sample-guile-project.

Ares depends on fibers, and on guile-custom-ports (is a part of guile since 3.0.10). Tests are executed with make check or within Arei using UI for ares.testing extension.

Send patches to rde-devel mailing list in format: [PATCH guile-ares-rs 0/3] SUBJECT-HERE.

Send feedback to rde-discuss.

Arei and Ares 1.0 milestone.

• How to work with fibers in nrepl? Maybe C-2 C-c C-e to entered to the clonned session with fibers spawned.
• Bootstrap from guile network repl? (Send guile-ares-rs implementation to remote network repl server to make it nrepl).
• Multiple guile languages support.
• How to bypass continuation barrier in evaluation thread, when using previously stored continuation.
• Translation level for shrothanded nrepl base operations?
• Do we need to support meta-commands? (Probably not, it just functions, which can be exported to user or repl module scope).

One of the reasons this project started is unfortunate missbehave of current REPL soultions in different situation and here is a list of some of them:

• Text based REPL over socket is not interruptible.
• call/cc works when pasted into prompt of the repl, but fails when evaling from buffer with C-x C-e. (when saving continuation to symbol with set!)
• It’s not possible to see stdout until evaluation completed.
• Gider tests hangs repl on errors.
• CAPF function is injected, even if there is no connection to REPL and throws errors preventing other CAPFs to work.
• There is no way to provide stdin input to running expression.
• Go to definition doesn’t work for with-input-from-port.
• After using ,i in REPL, go to definition hangs up.
• Go to definition opens non-existing file.
• If expression being evaluated from buffer requires input from stdin it will be frozen.
• Rebinds M-. instead of using xref.
• https://spritely.institute/files/docs/guile-goblins/0.11.0/TEMPORARY-Live-hacking-_0060_0060fix_0027_0027.html
• https://www.reddit.com/r/scheme/comments/qyqxcd/geiser_sucks_is_there_a_way_to_make_it_suck_less/
• Comment by Olical, Conjure author on guile-ares-rs integration

https://github.com/nrepl/nrepl

default clojure implementation.

https://nrepl.org/nrepl/1.0/building_servers.html

some tips.

https://gitlab.com/technomancy/ogion/-/blob/master/main.rkt

very simple Racket nREPL.

https://gitlab.com/technomancy/jeejah

lua nREPL server.

https://github.com/babashka/babashka.nrepl

probably most advanced 3rd party nREPL server implementation, doesn’t support interrupts.

https://docs.cider.mx/cider-nrepl/nrepl-api/ops.html#info

extensions of nREPL for CIDER.

• http://www.flow-storm.org/
• https://github.com/clojure-emacs/sayid
• https://github.com/philoskim/debux
• https://github.com/jpmonettas/flow-storm-debugger
• https://docs.cider.mx/cider/debugging/debugger.html
• https://www.gnu.org/software/guile/manual/html_node/Interactive-Debugging.html
• https://www.gnu.org/software/guile/manual/html_node/Debugging.html

• https://github.com/lambdaisland/nrepl-proxy

• https://github.com/sanel/monroe/
• https://github.com/Sasanidas/Rail
• Potentially Conjure, when nREPL for guile will be implemented in it.

• https://github.com/flatwhatson/grump/blob/master/grump-lib/bencode.scm
• https://github.com/caolan/chicken-bencode
• http://www.bittorrent.org/beps/bep_0003.html#bencoding
• https://wiki.theory.org/BitTorrentSpecification#Bencoding

Q: Can I use guile-ares-rs with an existing network REPL?

A: Theoretically it’s possible to upgrade existing REPL to guile-ares-rs, see bootstrap and infect modules (they can be not implemented yet).

Thanks for inspiration, help, support and motivation to Jos´e Antonio Ortega Ruiz, Nikita Domnitskii, Maxime Devos, Andy Wingo, Bozhidar Batsov, Andrey Listopadov, Dmitrii Bogdanov, David Thompson, Dmitry Polyakov.

A suitbl library is funded through NGI Zero Core, a fund established by NLnet with financial support from the European Commission’s Next Generation Internet program.

Learn more at the NLnet project page.