Kakoune

Introduction:

Kakoune is a code editor heavily inspired by Vim, as such most of it’s commands are similar to vi’s ones.

Kakoune can operate in two modes, normal and insertion. In insertion mode, keys are directly inserted into the current buffer. In normal mode, keys are used to manipulate the current selection and to enter insertion mode.

Kakoune has a strong focus on interactivity, most commands provide immediate and incremental results, while still being competitive (as in keystroke count) with Vim.

Kakoune works on selections, which are oriented, inclusive range of characters, selections have an anchor and a cursor character. Most commands move both of them, except when extending selection where the anchor character stays fixed and the cursor one moves around.

see http://vimeo.com/82711574

Join us on freenode IRC #Kakoune

Features

Multiple selection as a central way of interacting
Powerful selection manipulation primitives
- Select all regex matches in current selections
- Keep selections containing/not containing a match for a given regex
- Split current selections with a regex
- Text objects (paragraph, sentence, nestable blocks)
Powerful text manipulation primitives
- Align selections
- Rotate selection contents
- Case manipulation
- Indentation
- Piping each selection to external filter
Simple interaction with external programs
Automatic contextual help
Automatic as you type completion
Macros
Hooks
Syntax Highlighting

Building

Kakoune dependencies are:

A C++11 compliant compiler (GCC >= 4.8.1 or clang >= 3.4)
boost (>= 1.50)
ncurses with wide-characters support (>= 5.3, generally refered as libncursesw)
bash (kak scripts use some bash specific features)
socat (used by kak scripts to write to kak control socket)

To build, just type make in the src directory

Kakoune can be built on Linux, MacOS, and Cygwin. Due to Kakoune relying heavily on being in an Unix like environment, no native Windows version is planned.

To setup a basic configuration on your account, type make userconfig in the src directory, this will setup an initial $XDG_CONFIG_HOME/kak directory. See the Kakrc section for more information.

Installing

In order to install kak on your system, rather than running it directly from it’s source directory, type make install, you can specify the PREFIX and DESTDIR if needed.

Note that by default, no script files will be read if you do not add links to them in $XDG_CONFIG_HOME/kak/autoload. Available script files will be installed in $PREFIX/share/kak/rc

If you want to enable all files, set $XDG_CONFIG_HOME/kak/autoload to be a symbolic link to the $PREFIX/share/kak/rc directory.

ln -s /usr/share/kak/rc ~/.config/kak/autoload

Running

Just running kak launch a new kak session with a client on local terminal. kak accepts some switches:

-c <session>: connect to given session, sessions are unix sockets /tmp/kak-<session>
-e <commands>: execute commands on startup
-n: ignore kakrc file
-s <session>: set the session name, by default it will be the pid of the initial kak process.
-d: run Kakoune in daemon mode, without user interface. This requires the session name to be specified with -s. In this mode, the Kakoune server will keep running even if there is no connected client, and will quit when receiving SIGTERM.

At startup, if -n is not specified, Kakoune will try to source the file ../share/kak/kakrc relative to the kak binary. This kak file will then try to source $XDG_CONFIG_HOME/kak/kakrc (with $XDG_CONFIG_HOME defaulting to $HOME/.config), and any files in $XDG_CONFIG_HOME/kak/autoload.

The common pattern is to add links to $XDG_CONFIG_HOME/kak/autoload to the scripts in $PREFIX/share/kak/rc that the user wants sourced at kak launch.

Basic Movement

space: select the character under selection end
alt-space: flip the selections
h: select the character on the right of selection end
j: select the character below the selection end
k: select the character above the selection end
l: select the character on the left of selection end
w: select the word and following whitespaces on the right of selection end
b: select preceding whitespaces and the word on the left of selection end
e: select preceding whitespaces and the word on the right of selection end
alt-[wbe]: same as [wbe] but select WORD instead of word
x: select line on which selection end lies (or next line when end lies on an end-of-line)
alt-x: expand selections to contain full lines (including end-of-lines)
alt-X: trim selections to only contain full lines (not including last end-of-line)
%: select whole buffer
alt-H: select to line begin
alt-L: select to line end
/: search (select next match)
?: search (extend to next match)
n: select next match
N: add a new selection with next match
alt-n: replace main selection with next match (preserving the others)
pageup: scroll up
pagedown: scroll down
alt-r: rotate selections (the main selection becomes the next one)

Appending

for most selection commands, using shift permits to extend current selection instead of replacing it. for example, wWW selects 3 consecutive words

Using Counts

Most selection commands also support counts, which are entered before the command itself.

for example, 3W selects 3 consecutive words and 3w select the third word on the right of selection end.

space: when used with count, keep only the counth selection
alt-space: when used with count, remove the counth selection

Changes

i: insert before current selection
a: insert after current selection
d: yank and delete current selection
D: yank concatenated and delete current selection (see Y)
c: yank and delete current selection and insert
I: insert at current selection begin line start
A: insert at current selection end line end
o: insert in a new line below current selection end
O: insert in a new line above current selection begin
y: yank selections
Y: yank selections concatenated (only one yank, containing all selection concatenated)
p: paste after current selection end
P: paste before current selection begin
alt-p: replace current selection with yanked text
alt-j: join selected lines
alt-J: join selected lines and select spaces inserted in place of line breaks
>: indent selected lines
<: deindent selected lines
alt→: indent selected lines, including empty lines
<: deindent selected lines
alt-<: deindent selected lines, do not remove incomplete indent (3 leading spaces when indent is 4)
|: pipe each selections through the given external filter program and replace the selection with it’s output.
alt-|: pipe each selections through the given external filter program and append the selection with it’s output.
u: undo last change
U: redo last change
r: replace each character with the next entered one
&: align selection, align the cursor of selections by inserting spaces before the first character of the selection
alt-&: align indent, copy the indentation of the main selection (or the count one if a count is given) to all other ones
`: to lower case
~: to upper case
alt-`: swap case
alt-R: rotate selections content

Goto Commands

Commands begining with g are used to goto certain position and or buffer:

gh: select to line begin
gl: select to line end
gg, gk: go to the first line
gj: go to the last line
gt, gk: go to the first displayed line
gc, gk: go to the middle displayed line
gb: go to the last displayed line
ga: go to the previous (alternate) buffer
gf: open the file whose name is selected

View commands

Some commands, all begining with v permit to manipulate the current view.

vv or vc: center the main selection in the window
vt: scroll to put the main selection on the top line of the window
vb: scroll to put the main selection on the bottom line of the window
vh: scroll the window count columns left
vj: scroll the window count line downward
vk: scroll the window count line upward
vl: scroll the window count columns right

Jump list

Some commands, like the goto commands, buffer switch or search commands, push the previous selections to the client’s jump list. It is possible to forward or backward in the jump list using:

control-i: Jump forward
control-o: Jump backward
control-s: save current selections

Multi Selection

Kak was designed from the start to handle multiple selections. One way to get a multiselection is via the s key.

For example, to change all occurences of word roger to word marcel in a paragraph, here is what can be done:

select the paragraph with enough x. press s and enter roger then enter. now paragraph selection was replaced with multiselection of each roger in the paragraph. press c and marcel<esc> to replace rogers with marcels.

A multiselection can also be obtained with S, which splits the current selection according to the regex entered. To split a comma separated list, use S then , *

s and S share the search pattern with /, and hence entering an empty pattern uses the last one.

As a convenience, alt-s allows you to split the current selections on line boundaries.

To clear multiple selections, use space. To keep only the nth selection use n followed by space, to remove only the nth selection, use n followed by alt-space.

alt-k allows you to enter a regex and keep only the selections that contains a match for this regex. using alt-K you can keep the selections not containing a match.

Object Selection

Some keys allow you to select a text object:

alt-a: selects the whole object
alt-i: selects the inner object, that is the object excluding it’s surrounder. for example, for a quoted string, this will not select the quote, and for a word this will not select trailing spaces.
[: selects to object start
]: selects to object end
{: extends selections to object start
}: extends selections to object end

After this key, you need to enter a second key in order to specify which object you want.

b, ( or ): select the enclosing parenthesis
B, { or }: select the enclosing {} block
r, [ or ]: select the enclosing [] block
a, < or >: select the enclosing <> block
": select the enclosing double quoted string
': select the enclosing single quoted string
w: select the whole word
W: select the whole WORD
s: select the sentence
p: select the paragraph
i: select the current indentation block

For nestable objects, a count can be used in order to specify which surrounding level to select.

Registers

registers are named list of text. They are used for various purpose, like storing the last yanked test, or the captures groups associated with the selections.

While in insert mode, ctrl-r followed by a register name (one character) inserts it.

For example, ctrl-r followed by " will insert the currently yanked text. ctrl-r followed by 2 will insert the second capture group from the last regex selection.

Registers are lists, instead of simply text in order to interact well with multiselection. Each selection have it’s own captures, or yank buffer.

Macros

Kakoune can record and replay a sequence of key press.

When pressing the Q key, followed by an alphabetic key for the macro name, Kakoune begins macro recording: every pressed keys will be added to the macro until the Q key is pressed again.

To replay a macro, use the q key, followed by the macro name.

Search selection

Using the * key, you can set the search pattern to the current selection. This tries to be intelligent. It will for example detect if current selection begins and/or end at word boundaries, and set the search pattern accordingly.

with alt-* you can set the search pattern to the current seletion without Kakoune trying to be smart.

Basic Commands

Commands are entered using :.

e[dit] <filename> [<line> [<column>]]: open buffer on file, go to given line and column. If file is already opened, just switch to this file. use edit! to force reloading.
w[rite] [<filename>]: write buffer to <filename> or use it’s name if filename is not given.
q[uit]: exit Kakoune, use quit! to force quitting even if there is some unsaved buffers remaining.
wq: write current buffer and quit
b[uffer] <name>: switch to buffer <name>
d[el]b[uf] [<name>]: delete the buffer <name>, use d[el]b[uf]! to force deleting a modified buffer.
source <filename>: execute commands in <filename>
runtime <filename>: execute commands in <filename>, <filename> is relative to kak executable path.
nameclient <name>: set current client name
namebuf <name>: set current buffer name
echo <text>: show <text> in status line
name <name>: sets current client name to name
nop: does nothing, but as with every other commands, arguments may be evaluated. So nop can be used for example to execute a shell command while being sure that it’s output will not be interpreted by kak. :%sh{ echo echo tchou } will echo tchou in Kakoune, whereas :nop %sh{ echo echo tchou } will not, but both will execute the shell command.

Exec and Eval

the :exec and :eval commands can be used for running Kakoune commands. :exec keys as if they were pressed, whereas :eval executes it’s given paremeters as if they were entered in the command prompt. By default, they do their execution in the context of the current client.

Some parameters provide a way to change the context of execution:

-client <name>: execute in the context of the client named <name>
-draft: execute in a copy of the context of the selected client modifications to the selections or input state will not affect the client. This permits to make some modification to the buffer without modifying the user’s selection.
-itersel (requires -draft): execute once per selection, in a context with only the considered selection. This permits to avoid cases where the selections may get merged.

The execution stops when the last key/command is reached, or an error is raised.

key parameters gets concatenated, so the following commands are equivalent.

:exec otest<space>1
:exec o test <space> 1

String syntax

When entering a command, parameters are separated by whitespace (shell like), if you want to give parameters with spaces, you should quote them.

Kakoune support three string syntax:

"strings" and 'strings\': classic strings, use \' or \" to escape the separator.
%{strings}: these strings are very useful when entering commands
- the { and } delimiter are configurable: you can use any non alphanumeric character. like %[string], %<string>, %(string), %_string or %!string!…
- if the character following the % is one of {[(<, then the closing one is the matching }])> and the delimiters are not escapable but are nestable. for example %{ roger {}; } is a valid string, %{ marcel \} as well.

Options

For user configuration, Kakoune supports options.

Options are typed, their type can be

int: an integer number
bool: a boolean value, yes/true or no/false
yesnoask: similar to a boolean, but the additional value ask is supported.
str: a string, some freeform text
regex: as a string but the set commands will complain if the entered text is not a valid regex.
{int,str}-list: a list, elements are separated by a colon (:) if an element needs to contain a colon, it can be escaped with a backslash.

Options value can be changed using the set commands:

:set [global,buffer,window] <option> <value> # buffer, window, or global scope

Option values can be different by scope, an option can have a global value, a buffer value and a window value. The effective value of an option depends on the current context. If we have a window in the context (interactive edition for example), then the window value (if any) is used, if not we try the buffer value (if we have a buffer in the context), and if not we use the global value.

That means that two windows on the same buffer can use different options (like different filetype, or different tabstop). However some options might end up ignored if their scope is not in the command context:

Writing a file never uses the window options for example, so any options related to writing wont be taken into account if set in the window scope (BOM or eolformat for example).

New options can be declared using the :decl command:

:decl [-hidden] <type> <name> [<value>]

the -hidden parameter makes the option invisible in completion, but still modifiable.

Some options are built in Kakoune, and can be used to control it’s behaviour:

tabstop int: width of a tab character.
indentwidth int: width (in spaces) used for indentation. 0 means a tab character.
scrolloff int: number of lines to keep visible above/below the cursor when scrolling.
eolformat string (lf or crlf): the format of end of lines when writing a buffer, this is autodetected on load.
BOM string ("no" or "utf-8"): define if the file should be written with an unicode byte order mark.
shell string ("bash" by default): what command to run to evaluate shell commands.
complete_prefix bool: when completing in command line, and multiple candidates exist, enable completion with common prefix.
incsearch bool: execute search as it is typed
aligntab bool: use tabs for alignement command
autoinfo bool: display automatic information box for certain commands.
autoshowcompl bool: automatically display possible completions when editing a prompt.
ignored_files regex: filenames matching this regex wont be considered as candidates on filename completion (except if the text being completed already matches it).
filetype str: arbitrary string defining the type of the file filetype dependant actions should hook on this option changing for activation/deactivation.
completions str-list: option used for external completion, the first string should follow the format <line>.<column>[+<length>]@<timestamp> to define where the completion apply in the buffer, and the other strings are the candidates.
path str-list: directories to search for gf command.
completers str-list: completion systems to use for insert mode completion. Support option which use the completions option, and word=all or word=buffer which complete using words in all buffers (word=all) or only the current one (word=buffer)
autoreload yesnoask: auto reload the buffers when an external modification is detected.

Insert mode completion

Kakoune can propose completions while inserting text, the completers option control automatic completion, which kicks in when a certain idle timeout is reached (100 milliseconds). Insert mode completion can be explicitely triggered using control-x, followed, by:

f : filename completion
w : buffer word completion
o : option based completion

Highlighters

Manipulation of the displayed text is done through highlighters, which can be added or removed with the command

:addhl <highlighter_name> <highlighter_parameters...>

and

:rmhl <highlighter_id>

existing highlighters are:

number_lines: show line numbers
group <group_name>: highlighter group, containing other highlighters. useful when multiple highlighters work together and need to be removed as one. Adding and removing from a group can be done using :addhl -group <group> <highlighter_name> <highlighter_parameters...> :rmhl -group <group> <highlighter_name>
regex <ex> <color>…: highlight a regex, takes the regex as first parameter, followed by any number of color parameters. color format is: <capture_id>:<fg_color>[,<bg_color>] For example: :addhl regex //(\h+TODO:)?[^\n]+ 0:cyan 1:yellow,red will highlight C++ style comments in cyan, with an eventual TODO: in yellow on red background.
search <color>: highlight every matches to the current search pattern. takes one parameter for the color to apply to highlighted elements.
flag_lines <flag> <option_name>: add a column in front of text, and display the given flag in it for everly lines contained in the int-list option named <option_name>.
show_matching: highlight matching char of the character under the selections cursor using MatchingChar color alias.

Shared Highlighters

Highlighters are often defined for a specific filetype, and it makes then sense to share the highlighters between all the windows on the same filetypes.

A shared highlighter can be defined with

defhl <shared_hl_name>

Highlighters can be added to it using the regular :addhl command, with the -def-group <shared_hl_name> option.

It can then be referenced in a window using the ref highlighter.

addhl ref <shared_hl_name>

Hooks

commands can be registred to be executed when certain events arise. to register a hook, use the hook command.

:hook <scope> <hook_name> <filtering_regex> <commands>

<scope> can be either global, buffer or window (or any of their prefixes), the scope are hierarchical, meaning that a Window calling a hook will execute it’s own, the buffer ones and the global ones.

<command> is a string containing the commands to execute when the hook is called.

for example, to automatically use line numbering with .cc files, use the following command:

:hook global WinCreate .*\.cc %{ addhl number_lines }

existing hooks are:

NormalIdle: A certain duration has passed since last key was pressed in normal mode.
NormalBegin: Entering normal mode
NormalEnd: Leaving normal mode
NormalKey: A key is received in normal mode, the key is used for filtering
InsertIdle: A certain duration has passed since last key was pressed in insert mode.
InsertBegin: Entering insert mode
InsertEnd: Leaving insert mode
InsertKey: A key is received in insert mode, the key is used for filtering
InsertMove: The cursor moved (without inserting) in insert mode, the key that triggered the move is used for filtering
WinCreate: A window was created, the filtering text is the buffer name
WinClose: A window was detroyed, the filtering text is the buffer name
WinDisplay: A window was bound a client, the filtering text is the buffer name
WinSetOption: An option was set in a window context, the filtering text is <option_name>=<new_value>
BufSetOption: An option was set in a buffer context, the filtering text is <option_name>=<new_value>
BufNew: A buffer for a new file has been created, filename is used for filtering
BufOpen: A buffer for an existing file has been created, filename is used for filtering
BufCreate: A buffer has been created, filename is used for filtering
BufWritePre: Executre just before a buffer is written, filename is used for filtering.
BufWritePost: Executre just after a buffer is written, filename is used for filtering.
RuntimeError: an error was encountered while executing an user command the error message is used for filtering
KakBegin: Kakoune started, this is called just after reading the user configuration files
KakEnd: Kakoune is quitting.

when not specified, the filtering text is an empty string.

Key Mapping

You can redefine keys meaning using the map command

:map <scope> <mode> <key> <keys>

with scope being one of global, buffer or window (or any prefix), mode being insert, normal, prompt or menu (or any prefix), key being a single key name and keys a list of keys.

Color Aliases

Colorspec takes the form <fg_color>[,<bg_color>], they can be named using the following command.

:colalias <name> <colspec>

note that colspec can itself be a color alias.

Using color alias instead of colorspec permits to change the effective colors afterward.

there are some builtins color aliases:

PrimarySelection: main selection color for every selected character except the cursor
SecondarySelection: secondary selection color for every selected character except the cursor
PrimaryCursor: cursor of the primary selection
SecondaryCursor: cursor of the secondary selection
LineNumbers: colors used by the number_lines highlighter
MenuForeground: colors for the selected element in menus
MenuBackground: colors for the not selected elements in menus
Information: colors the informations windows and information messages
Error: colors of error messages
StatusLine: colors used for the status line
StatusCursor: colors used for the status line cursor
Prompt: colors used prompt displayed on the status line

Shell expansion

A special string syntax is supported which replace it’s content with the output of the shell commands in it, it is similar to the shell $(…) syntax and is evaluated only when needed. for example: %sh{ ls } is replaced with the output of the ls command.

Some of Kakoune state is available through environment variables:

kak_selection: content of the main selection
kak_selections: content of the selection separated by colons, colons in the selection contents are escapted with a backslash.
kak_bufname: name of the current buffer
kak_timestamp: timestamp of the current buffer, the timestamp is an integer value which is incremented each time the buffer is modified.
kak_runtime: directory containing the kak binary
kak_opt_<name>: value of option <name>
kak_reg_<r>: value of register <r>
kak_socket: filename of session socket (/tmp/kak-<session>)
kak_client: name of current client
kak_cursor_line: line of the end of the main selection
kak_cursor_column: column of the end of the main selection (in byte)
kak_cursor_char_column: column of the end of the main selection (in character)
kak_hook_param: filtering text passed to the currently executing hook

Note that in order to make only needed information available, Kakoune needs to find the environment variable reference in the shell script executed. Hence %sh{ ./script.sh } with script.sh referencing an environment will not work.

for example you can print informations on the current file in the status line using:

:echo %sh{ ls -l $kak_bufname }

Register and Option expansion

Similar to shell expansion, register contents and options values can be accessed through %reg{<register>} and %opt{<option>} syntax.

for example you can display last search pattern with

:echo %reg{/}

Defining Commands

new commands can be defined using the :def command.

:def <command_name> <commands>

<commands> is a string containing the commands to execute

def can also takes some flags:

-env-params: pass parameters given to commands in the environment as kak_paramN with N the parameter number
-shell-params: pass parameters given to commands as positional parameters to any shell expansions used in the command.
-file-completion: try file completion on any parameter passed to this command
-shell-completion: following string is a shell command which takes parameters as positional params and output one completion candidate per line.
-allow-override: allow the new command to replace an exisiting one with the same name.
-hidden: do not show the command in command name completions

Using shell expansion permits to define complex commands or to access Kakoune state:

:def print_selection %{ echo %sh{ ${kak_selection} } }

Some helper commands can be used to define composite commands:

:menu <label1> <commands1> <label2> <commands2>…: display a menu using labels, the selected label’s commands are executed. menu can take a -auto-single argument, to automatically run commands when only one choice is provided. and a -select-cmds argument, in which case menu takes three argument per item, the last one being a command to execute when the item is selected (but not validated).
:info <text>: display text in an information box, at can take a -anchor option, which accepts left, right and cursor as value, in order to specify where the info box should be anchored relative to the main selection.
:try <commands> catch <on_error_commands>: prevent an error in <commands> from aborting the whole commands execution, execute <on_error_commands> instead. If nothing is to be done on error, the catch part can be ommitted.
:reg <name> <content>: set register <name> to <content>

Note that these commands are available in interactive command mode, but are not that useful in this context.

FIFO Buffer

the :edit command can take a -fifo parameter:

:edit -fifo <filename> <buffername>

in this case, a buffer named <buffername> is created which reads its content from fifo <filename>. When the fifo is written to, the buffer is automatically updated.

This is very useful for running some commands asynchronously while displaying their result in a buffer. See rc/make.kak and rc/grep.kak for examples.

When the buffer is deleted, the fifo will be closed, so any program writing to it will receive SIGPIPE. This is usefull as it permits to stop the writing program when the buffer is deleted.

Menus

When a menu is displayed, you can use j, control-n or tab to select the next entry, and k, control-p or shift-tab to select the previous one.

Using the / key, you can enter some regex in order to restrict available choices to the matching ones.

Kakrc

The kakrc file next to the kak binary (in the src directory for the moment) is a list of kak commands to be executed at startup.

The current behaviour is to execute local user commands in the file $HOME/.config/kak/kakrc and in all files in $HOME/.config/kak/autoload directory

Place links to the files in src/rc/ in your autoload directory in order to execute them on startup, or use the runtime command (which sources relative to the kak binary) to load them on demand.

Existing commands files are:

rc/kakrc.kak: provides kak commands files autodetection and highlighting
rc/cpp.kak: provides C/CPP files autodetection and highlighting and the :alt command for switching from C/CPP file to h/hpp one.
rc/asciidoc.kak: provides asciidoc files autodetection and highlighting
rc/diff.kak: provides patches/diff files autodetection and highlighting
rc/git.kak: provides various git format highlighting (commit message editing, interactive rebase)
rc/git-tools.kak: provides some git integration, like :git-blame, :git-show or :git-diff-show
rc/make.kak: provides the :make and :errjump commands along with highlighting for compiler output.
rc/man.kak: provides the :man command
rc/grep.kak: provides the :grep and :gjump commands along with highlighting for grep output.
rc/ctags.kak: provides the :tag command to jump on a tag definition using exuberant ctags files, this script requires the readtags binary, available in the exuberant ctags package but not installed by default.
rc/client.kak: provides the :new command to launch a new client on the current session, if tmux is detected, launch the client in a new tmux split, else launch in a new terminal emulator.
rc/clang.kak: provides the :clang-enable-autocomplete command for C/CPP insert mode completion support. This needs clang++ compiler.

Certain command files defines options, such as grepcmd (for :grep) makecmd (for :make) or termcmd (for :new).

Some options are shared with commands. grep and make honor the toolsclient option, if specified, to open their buffer in it rather than the current client. man honor the docsclient option for the same purpose.

nojhan / kakoune