vim-slime

Demo

What is Vim-Slime?

Context for SLIME:

SLIME is an Emacs plugin to turn Emacs into a Lisp IDE. You can type text
in a file, send it to a live REPL, and avoid having to reload all your code
every time you make a change.

Vim-slime is a humble attempt at getting _some_ of these features into Vim.
It works with any REPL and isn't tied to Lisp.

Grab some text and send it to a target, most probably: GNU Screen, tmux or Vim Terminal.

Presumably, your target contains a REPL, maybe Clojure, R or python. If you can type text into it, vim-slime can send text to it.

The reason for doing this? Because you want the benefits of a REPL (instant feedback, no need to reload ...) and the benefits of using Vim (familiar environment, syntax highlighting, persistence ...).

More details in the blog post.

Many targets are supported:

• GNU Screen
• tmux
• dtach
• kitty
• X11
• whimrepl
• ConEmu
• Vim :terminal
• NeoVim :terminal
• wezterm

Installation

Use your favorite package manager, or use Vim's built-in package support (since Vim 7.4.1528):

mkdir -p ~/.vim/pack/plugins/start
cd ~/.vim/pack/plugins/start
git clone https://github.com/jpalardy/vim-slime.git

Alternatively, you can try vim-slime in Docker, before committing to anything else.

Usage

Put your cursor over the text you want to send and type:

ctrl-c ctrl-c --- the same as slime

(You can just hold ctrl and double-tap c.)

The current paragraph — what would be selected if you typed vip — is automatically selected.

To control exactly what is sent, you can manually select text before calling vim-slime.

Config prompt

Vim-slime needs to know where to send your text, it will prompt you. It will remember your answers and won't prompt you again.

But, if you want to reconfigure, to force the config prompt again, type:

ctrl-c v --- mnemonic: "variables"

or call:

:SlimeConfig

Configuration

GNU Screen

By default, GNU Screen is assumed, you don't have to do anything. If you want to be explicit, you can add this line to your .vimrc:

let g:slime_target = "screen"

Because Screen doesn't accept input from STDIN, a file is used to pipe data between Vim and Screen. By default this file is set to $HOME/.slime_paste. The name of the file used can be configured through a variable:

let g:slime_paste_file = expand("$HOME/.slime_paste")
" or maybe...
let g:slime_paste_file = tempname()

⚠️ This file is not erased by the plugin and will always contain the last thing you sent over.

When you invoke vim-slime for the first time, you will be prompted for more configuration.

screen session name:

This is what you put in the -S flag, or one of the line from "screen -ls".

screen window name:

This is the window number or name, zero-based.

tmux

Tmux is not the default, to use it you will have to add this line to your .vimrc:

let g:slime_target = "tmux"

Before tmux 2.2, tmux accepted input from STDIN. This doesn't work anymore. To make it work out without explicit config, the default was changed to use a file like Screen. By default this file is set to $HOME/.slime_paste. The name of the file used can be configured through a variable:

let g:slime_paste_file = expand("$HOME/.slime_paste")
" or maybe...
let g:slime_paste_file = tempname()

⚠️ This file is not erased by the plugin and will always contain the last thing you sent over.

When you invoke vim-slime for the first time, you will be prompted for more configuration.

tmux socket name or absolute path:

If you started tmux with the -L or -S flag, use that same socket name or path here.
If you didn't put anything, the default name is "default".

tmux target pane:

Note that all of these ordinals are 0-indexed by default.

":"       means current window, current pane (a reasonable default)
":i"      means the ith window, current pane
":i.j"    means the ith window, jth pane
"h:i.j"   means the tmux session where h is the session identifier
          (either session name or number), the ith window and the jth pane
"%i"      means i refers the pane's unique id
"{token}" one of tmux's supported special tokens, like "{last}"

You can configure the defaults for these options. If you generally run vim in a split tmux window with a REPL in the other pane:

let g:slime_default_config = {"socket_name": get(split($TMUX, ","), 0), "target_pane": ":.2"}

Or more reliably by employing a special token as pane index:

let g:slime_default_config = {"socket_name": "default", "target_pane": "{last}"}

tmux bracketed-paste

Sometimes REPL are too smart for their own good, e.g. autocompleting a bracket that should not be autocompleted when pasting code from a file. In this case it can be useful to rely on bracketed-paste (https://cirw.in/blog/bracketed-paste). Luckily, tmux knows how to handle that. See tmux's manual. Setting g:slime_bracketed_paste to 1 in your .vimrc enables or disables bracketed-paste. It is disabled by default because it can create issues with ipython. See #265.

dtach

dtach is not the default, to use it you will have to add this line to your .vimrc:

let g:slime_target = "dtach"

When you invoke vim-slime for the first time, you will be prompted for more configuration.

socket_path:

The path to the Unix-domain socket that the dtach session is attached to.
The default is /tmp/slime

kitty

kitty is not the default, to use it you will have to add this line to your .vimrc:

let g:slime_target = "kitty"

When you invoke vim-slime for the first time, you will be prompted for more configuration.

kitty target window

This is the id of the kitty window that you wish to target.
See e.g. the value of $KITTY_WINDOW_ID in the target window.

kitty listen on

Specifies where kitty should listen to control messages.
See e.g. the value of $KITTY_LISTEN_ON in the target window.

Can be left blank if:
- KITTY_LISTEN_ON is exported in the shell running vim
- running vim (but not nvim) inside kitty

To work properly, kitty must also be started with the following options:

kitty -o allow_remote_control=yes --listen-on unix:/tmp/mykitty

See more here. This can also be added to your kitty.conf file as:

allow_remote_control yes
listen_on unix:/tmp/mykitty

Zellij

Zellij is not the default, to use it you will have to add this line to your .vimrc:

let g:slime_target = "zellij"

When you invoke vim-slime for the first time, you will be prompted for more configuration.

Zellij session id

This is the id of the zellij session that you wish to target, the default value is "current" meaning the session containing the vim pane.
See e.g. the value of "zellij list-sessions" in the target window to figure out specific session names.

Zellij relative pane

"current" for the currently active pane
"up"/"down"/"right"/"left" for the pane in that direction relative to the location of the active pane

You can configure the defaults for these options. If you generally run vim in a split zellij window with a REPL to the right it could look like this:

let g:slime_default_config = {"session_id": "current", "relative_pane": "right"}

X11

x11 is not the default, to use it you will have to add this line to your .vimrc:

let g:slime_target = "x11"

When you invoke vim-slime for the first time, you will have to designate a target window by clicking on it.

Troubleshooting

If SlimeConfig hangs without asking you to select a target terminal, you may not have xdotool installed.

If SlimeConfig works and you can send text to the terminal window running vim but not to other terminal windows, your terminal may be configured to ignore the XSendEvent events generated by xdotool by default. See the SENDEVENT NOTES section of the xdotool man page for details. Note also that allowing arbitrary programs to send text to your terminal to be executed is potentially a security vulnerability.

whimrepl

whimrepl is not the default, to use it you will have to add this line to your .vimrc:

let g:slime_target = "whimrepl"

When you invoke vim-slime for the first time, you will be prompted for more configuration.

whimrepl server name

This is the name of the whimrepl server that you wish to target.  whimrepl
displays that name in its banner every time you start up an instance of
whimrepl.

ConEmu

ConEmu is not the default, to use it you will have to add this line to your .vimrc:

let g:slime_target = "conemu"

When you invoke vim-slime for the first time, you will be prompted for more configuration.

ConEmu console server HWND

This is what you put in the -GuiMacro flag. It will be "0" if you didn't put
anything, addressing the active tab/split of the first found ConEmu window.

By default the windows clipboard is used to pass the text to ConEmu. If you experience issues with this, make sure the conemuc executable is in your path.

Vim :terminal

Vim :terminal is not the default, to use it you will have to add this line to your .vimrc:

let g:slime_target = "vimterminal"

When you invoke vim-slime for the first time, you will be prompted for more configuration.

Vim terminal configuration can be set by using the following in your .vimrc:

let g:slime_vimterminal_config = {options}

You can specify if you have frequently used commands:

let g:slime_vimterminal_cmd = "command"

If you use Node, set it as follows:

let g:slime_vimterminal_cmd = "node"

You can make the vim terminal closed automatically, if you set the g:slime_vimterminal_cmd:

let g:slime_vimterminal_config = {"term_finish": "close"}

for possible options, see :help term_start()

NeoVim :terminal

NeoVim :terminal is not the default, to use it you will have to add this line to your .vimrc:

let g:slime_target = "neovim"

When you invoke vim-slime for the first time, you will be prompted for more configuration. The last terminal you opened before calling vim-slime will determine which job-id is presented as default.

To manually check the right value of job-id to use, try:

echo &channel

from the buffer running your terminal.

You can also specify a function to query the jobid as

vim.g.slime_get_jobid = function()
  -- some way to select and return jobid
end

wezterm

wezterm is not the default, to use it you will have to add this line to your .vimrc:

let g:slime_target = "wezterm"

When you invoke vim-slime for the first time, you will be prompted for more configuration.

wezterm pane id

This is the id of the wezterm pane that you wish to target.
See e.g. the value of $WEZTERM_PANE in the target pane.

Advanced Configuration

If you need this, you might as well refer to the code 😄
Seriously, it's not a complicated as it seems.

If you don't want the default key mappings, set:

let g:slime_no_mappings = 1

The default mappings are:

xmap <c-c><c-c> <Plug>SlimeRegionSend
nmap <c-c><c-c> <Plug>SlimeParagraphSend
nmap <c-c>v     <Plug>SlimeConfig

If you want vim-slime to prefill the prompt answers, you can set a default configuration:

" screen:
let g:slime_default_config = {"sessionname": "xxx", "windowname": "0"}

" tmux:
let g:slime_default_config = {"socket_name": "default", "target_pane": "1"}

If you want vim-slime to bypass the prompt and use the specified default configuration options, set the g:slime_dont_ask_default option:

let g:slime_dont_ask_default = 1

By default, vim-slime will try to restore your cursor position after it runs. If you don't want that behavior, unset the g:slime_preserve_curpos option:

let g:slime_preserve_curpos = 0

If you want to send blocks of code between two delimiters, emulating the cell-like mode of REPL environments like ipython, matlab, etc., you can set the cell delimiter on the g:slime_cell_delimiter variable and use the <Plug>SlimeSendCell mapping to send the block of code. For example, if you are using ipython you could use the following:

let g:slime_cell_delimiter = "#%%"
nmap <leader>s <Plug>SlimeSendCell

⚠️ it's recommended to use b:slime_cell_delimiter and set the variable in ftplugin for each relevant filetype.

Advanced Configuration: Overrides

At the end of the day, you might find that vim-slime ALMOST does everything you need, but not quite the way you like it. You might be tempted to fork it, but the idea of writing and maintaining vimscript is daunting (trust me: I sympathize 😐).

You can override some logic and still benefit from the rest of vim-slime. Here's the mental model you need to understand how things work:

1. you invoke a key binding and vim-slime grabs a chunk of text
2. depending on which language you are using (see below), the text might be "transformed" and "massaged" to paste correctly
3. if the config is missing, the user is prompted to fill in the blanks
4. a target-specific function is called to delegate the "send this text to the right target" part
5. the target receives the right text, the right way, and everything works

There is some good news, for step 2, 3, 4, you can override the logic with your own functions! Put these functions in your .vimrc and hijack the part you need.

You can override any or all (zero to many) of these functions, as needed.

Why is this awesome?

• skip vimscript: delegate to an external script; written in your own preferred language
• optimize for you: treat yourself with just-for-you customizations and hardcoded values
• ultimate power: beyond config and flags, passing a function means you can do anything you want

You might still need some vimscript to glue things together. Leaning on the vim-slime code for examples might get you 90% of what you need. If not, there's always Learn Vimscript the Hard Way.

If you feel others can benefit from your customizations, open a PR and we'll find a way.

How to override "language transformations"?

Write a function named SlimeOverride_EscapeText_#{language}:

function SlimeOverride_EscapeText_python(text)
  return system("some-command-line-script", a:text)
endfunction

This example code, for Python in this case, pushes the selected text to some-command-line-script through STDIN and returns whatever that script produced through STDOUT.

Contract:

• input is selected text
• output is string or an array of strings (see other ftplugin for details)

How to override "configuration"?

Write a function named SlimeOverrideConfig:

function SlimeOverrideConfig()
  let b:slime_config = {}
  let b:slime_config["key"] = input("key: ", "default value")
endfunction

Contract:

• no input, but...
• b:slime_config might contain g:slime_default_config if it was defined, or be undefined otherwise
• no output but...
• b:slime_config expected to contain necessary keys and values used by the target send function (up next)

How to override "send to target"?

Write a function named SlimeOverrideSend:

function SlimeOverrideSend(config, text)
  echom a:config
  call system("send-to-target --key " . a:config["key"], a:text)
endfunction

Contract:

• inputs are config (from config function, above or default) and selected text (post transformation)
• no output but...
• expected to do whatever is needed to send to target, probably a call to system but see code for details

Language Support

Vim-slime might have to modify its behavior according to the language or REPL you want to use.

Many languages are supported without modifications, while others might tweak the text without explicit configuration:

• coffee-script
• elm
• fsharp
• haskell / lhaskell -- README
• matlab
• ocaml
• python / ipython -- README
• scala / ammonite -- README
• sml
• stata

Advanced cell-features

If you need more advanced cell features, such as syntax highlighting or cell navigation, you might want to have a look at vim-slime-cells.