= Options

== Description

Kakoune can store named and typed values that can be used both to
customize the core editor behaviour, and to store data used by extension
scripts.

[[set-option]]
Options can be modified using the `set-option` command:

--------------------------------------------
set-option [-add] <scope> <name> <values>...
--------------------------------------------

<scope> can be *global*, *buffer*, *window* or *current* (See
<<scopes#,`:doc scopes`>>). *current* relates to the narrowest scope in
which the option is already set.

Multiple <values> can be given as separate arguments when the option is a
list or map.

If `-add` is specified, the new value is *added* to the current one
instead of replacing it (the exact outcome depends on the type, see below).

[[unset-option]]
Options values can be unset in a specific scope with the `unset-option`
command:

---------------------------
unset-option <scope> <name>
---------------------------

Unsetting an option will make it fallback to the value of its parent mode,
hence options cannot be unset from the *global* scope.

[[declare-option]]
New options can be declared using the `declare-option` command:

---------------------------------------------------
declare-option [-hidden] <type> <name> [<value>...]
---------------------------------------------------

If `-hidden` is specified, the option will not be displayed in completion
suggestions.

[[update-option]]
Certain option type can be *updated*, usually to match potential changes
in the buffer they relate to. This can be triggered by the `update-option`
command:

----------------------------
update-option <scope> <name>
----------------------------

== Types

All options have a type, which defines how they are translated to/from
text and their set of valid values.

Some types are usable for user defined options while some other types
are exclusively available to built-in options.

*int*::
    an integer number.
    `set -add` performs a math addition

*bool*::
    a boolean value, yes/true or no/false

*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

*coord*::
    a line, column pair (separated by a comma)
    Cannot be used with `declare-option`

*<type>-list*::
    a list, elements are specified as separate arguments to the command.
    `set -add` appends the new element to the list
    Only `int-list` and `str-list` options can be created with
    `declare-option`.

*range-specs*::
    a list of a pair of a buffer range (`<begin line>.<begin column>,
    <end line>.<end column>` or `<begin line>.<begin column>+<length>`)
    and a string (separated by `|`), except for the first element which
    is just the timestamp of the buffer. When the `update-option` is
    used on an option of this type, its ranges gets updated according
    to all the buffer modifications that happened since its timestamp.
    See <<highlighters#specs-highlighters,`:doc highlighters specs-highlighters`>>)
    `set -add` appends the new pair to the list

*line-specs*::
    a list of a line number and a corresponding flag (`<line>|<flag
    text>`), except for the first element which is just the timestamp
    of the buffer. When the `update-option` is used on an option of this
    type, its lines gets updated according to all the buffer modifications
    that happened since its timestamp.
    See <<highlighters#specs-highlighters,`:doc highlighters specs-highlighters`>>)
    `set -add` appends the new spec to the list

*completions*::
    a list of `<text>|<docstring>|<menu text>` candidates,
    except for the first element which follows the
    `<line>.<column>[+<length>]@<timestamp>` format to define where the
    completion apply in the buffer. Markup can be used in the menu text.
    `set -add` adds a new completion to the list

*enum(value1|value2|...)*::
    an enum, taking one of the given values
    Cannot be used with `declare-option`

*flags(value1|value2|...)*::
    a set of flags, taking a combination of the given values joined by a
    '|' character.
    `set -add` adds the new flag to the combination
    Cannot be used with `declare-option`

*<type>-to-<type>-map*::
    a list of `key=value` pairs.
    `set -add` adds the new pair to the hashmap or replace an already
    existing key.
    Only `str-to-str-map` options can be created with `declare-option`.

== Builtin options

*tabstop* `int`::
    _default_ 8 +
    width of a tab character

*indentwidth* `int`::
    _default_ 4 +
    width (in spaces) used for indentation, 0 means a tab character

*scrolloff* `coord`::
    _default_ 0,0 +
    number of lines, columns to keep visible around the cursor when
    scrolling

*eolformat* `enum(lf|crlf)`::
    _default_ lf +
    the format of end of lines when writing a buffer, this is autodetected
    on load; values of this option assigned to the `window` scope are
    ignored

*BOM* `enum(none|utf8)`::
    _default_ none +
    define if the file should be written with a unicode byte order mark;
    values of this option assigned to the `window` scope are ignored

*readonly* `bool`::
    _default_ false +
    prevent modifications from being saved to disk, all buffers if set
    to `true` in the `global` scope, or current buffer if set in the
    `buffer` scope; values of this option assigned to the `window`
    scope are ignored

*incsearch* `bool`::
    _default_ true +
    execute search as it is typed

*aligntab* `bool`::
    _default_ false +
    use tabs for alignment command

*autoinfo* `flags(command|onkey|normal)`::
    _default_ command|onkey +
    display automatic information box in the enabled contexts

*auto_complete* `flags(insert|prompt)`::
    _default_ insert|prompt +
    automatically display possible completions in the enabled modes.

*ignored_files* `regex`::
    filenames matching this regex won't be considered as candidates
    on filename completion (except if the text being completed already
    matches it)

*disabled_hooks* `regex`::
    hooks whose group matches this regex won't be executed. For example
    indentation hooks can be disabled with `.*-indent`.
    (See <<hooks#disabling-hooks,`:doc hooks`>>)

*filetype* `str`::
    arbitrary string defining the type of the file. Filetype dependent
    actions should hook on this option changing for activation/deactivation

*path* `str-list`::
    _default_ ./ %/ /usr/include +
    directories to search for *gf* command and filenames completion
    `%/` represents the current buffer directory

*completers* `completer-list`::
    _default_ filename word=all +
    completion engines to use for insert mode completion (they are tried
    in order until one generates candidates). Existing completers are:

    *word=all*, *word=buffer*:::
        which complete using words in all buffers (*word=all*)
        or only the current one (*word=buffer*)

    *filename*:::
        which tries to detect when a filename is being entered and
        provides completion based on local filesystem

    *line*:::
        which complete using lines in current buffer

    *option=<opt-name>*:::
        where *opt-name* is an option of type 'completions' whose
        contents will be used

*static_words* `str-list`::
    list of words that are always added to completion candidates
    when completing words in insert mode

*extra_word_chars* `codepoint-list`::
    a list of all additional codepoints that should be considered
    as word character.

*matching_pairs* `codepoint-list`::
    _default_ ( ) { } [ ] < > +
    a list of codepoints that are to be treated as matching pairs
    for the *m* command.

*autoreload* `enum(yes|no|ask)`::
    _default_ ask +
    auto reload the buffers when an external modification is detected

*debug* `flags(hooks|shell|profile|keys|commands)`::
    dump various debug information in the '\*debug*' buffer

*idle_timeout* `int`::
    _default_ 50 +
    timeout, in milliseconds, with no user input that will trigger the
    *PromptIdle*, *InsertIdle* and *NormalIdle* hooks, and autocompletion.

*fs_checkout_timeout* `int`::
    _default_ 500 +
    timeout, in milliseconds, between checks in normal mode of modifications
    of the file associated with the current buffer on the filesystem.

*modelinefmt* `string`::
    A format string used to generate the mode line, that string is
    first expanded as a command line would be (expanding '%...{...}'
    strings), then markup tags are applied (See <<expansions#,`:doc expansions`>>)
    Two special atoms are available as markup:

        *`{{mode_info}}`*:::
            Information about the current mode, such as `insert 3 sel` or
            `prompt`. The faces used are StatusLineMode, StatusLineInfo,
            and StatusLineValue.

        *`{{context_info}}`*:::
            Information such as `[+][recording (@)][no-hooks][new file][fifo]`,
            in face Information.

    The default value is '%val{bufname} %val{cursor_line}:%val{cursor_char_column} {{context_info}} {{mode_info}} - %val{client}@[%val{session}]'

*ui_options* `str-to-str-map`::
    a list of `key=value` pairs that are forwarded to the user
    interface implementation. The NCurses UI support the following options:

        *ncurses_set_title*:::
            if *yes* or *true*, the terminal emulator title will
            be changed

        *ncurses_status_on_top*:::
            if *yes*, or *true* the status line will be placed
            at the top of the terminal rather than at the bottom

        *ncurses_assistant*:::
            specify the nice assistant displayed in info boxes,
            can be *clippy* (the default), *cat*, *dilbert* or *none*

        *ncurses_enable_mouse*:::
            boolean option that enables mouse support

        *ncurses_change_colors*:::
            boolean option that can disable color palette changing if the
            terminfo enables it but the terminal does not support it.

        *ncurses_wheel_down_button*, *ncurses_wheel_up_button*:::
            specify which button send for wheel down/up events

        *ncurses_shift_function_key*:::
            Function key from which shifted function key start, if the
            terminal sends F13 for <s-F1>, this should be set to 12.

[[startup-info]]
*startup_info_version* `int`::
    _default_ 0 +
    Controls which messages will be displayed in the startup info box, only messages
    relating to a Kakoune version greater than this value will be displayed. Versions
    are written as a single number: Like `20180413` for version `2018.04.13`
