Update: Mirror that includes _protocol and is compatible with Lua packag managers such as Lazy by fixing submodule issue.
This is an interactive Fennel REPL plugin for Neovim. It allows evaluating arbitrary Fennel expressions in a running process. The expression is sent to the application, evaluated, and the result is sent back to Neovim.
Warning
This plugin executes arbitrary code. Do not start a REPL automatically. Do not run code you do not trust. There is no sandboxing going on here, what you enter will be executed.
Requires Fennel 1.3.1 or higher running in the application you want to connect to.
Install this plugin like any other Neovim plugin, then make sure the
_protocol Git submodule has been initialised and checkout precisely to the
version of this plugin. The plugin communicates with the REPL process through
a protocol, and the submodule ships an implementation of said protocol.
Therefore it is important to keep the plugin and protocol implementation
synchronised.
If you were doing it by hand you would do execute these commands:
git clone --recurse-submodules https://gitlab.com/HiPhish/fennel-repl.nvim.gitTo check out the correct version of the submodule:
git submodule update --checkout _protocolIf you are using a package manager please refer to its documentation on how to manage submodules.
Install it like any other Neovim plugin. You do not need Fennel installed, but the application you want to hook up to has to expose some sort of Fennel REPL over standard IO. If it does not (e.g. Löve2D) you have to write code to expose the REPL yourself.
Execute :Fennel start <fennelprg> <arg>... (e.g. Fennel start love .
--repl) to start the process which exposes a Fennel REPL over its standard IO.
This command might change in the future!
A source named fennel-repl for `nvim-cmp`_ is included for convenience. This
source will probably become its own plugin in the future, so do not rely on it
being here.
The public interface of the plugin will change. Do not rely on it.
The following functionality is available:
- Evaluate Fennel expressions (like the command-line REPL)
- Execute comma-commands (like the command-line REPL)
- Interactive stack trace
- Syntax highlighting (only regular Vim highlighting no Tree-sitter)
- Auto-completion and symbol documentation
- Reloading modules from buffers
- Buffer expression evaluation
What would be nice to have:
- REPL history
- Ability to connect to a running process instead of starting a new one; this would also require the ability to "downgrade" the REPL and disconnect without terminating the process
- Ability to register new comma-commands
- Ability to define new sub-commands
- Option like
--no-upgradeto not upgrade the REPL (maybe not a good idea?) - Auto-completion does not include the type of the completion item (probably not useful with CMP because the type of an object does not map onto an LSP completion type)
I don't know if the following are even possible, but here is a list of what else I would really like to see.
A (floating?) window which lets the user view a table, dig into its values, and alter them. Metatables might complicate this because they allow overwriting functionality like indexing. There is also the question as to how to inspect values local to a module.
When execution hits an error or breakpoint the REPL send a message to the editor to start debugging. The editor then attaches to the debug adapter inside the REPL and the two start a debug session. This would require that the editor upload the necessary code to the REPL after initialization. Then whenever a breakpoint is set the editor sends a "breakpoint" message to the REPL so it can install the corresponding hook.
Currently the REPL runs inside a separate process. For Neovim it would make sense if the REPL was running right inside the editor itself. This would require a different class of REPL which does not wrap around a job.
Integrate with a test runner plugin. I am not sure if this is really a good idea though, tests are meant to run in isolation.
Licensed under the MIT (Expat) license. Please see the LICENSE file for details.
This plugin is inspired by the REPL plugin for Emacs. Relevant links: