365 lines
13 KiB
Plaintext
365 lines
13 KiB
Plaintext
= Expansions
|
||
|
||
While parsing a command (see <<command-parsing#,`:doc command-parsing`>>),
|
||
Kakoune recognises certain patterns and will replace them with their
|
||
associated value before executing the command. These patterns are called
|
||
expansions.
|
||
|
||
Every expansion consists of a `%`, followed by the expansion _type_ (one
|
||
or more alphabetic characters), a quoting character, and then all the text
|
||
up to and including its matching character.
|
||
|
||
If a nestable punctuation character (`(`, `[`, `{`, or `<`) is used as the
|
||
opening quoting character, the expansion will end at its matching opposite
|
||
(`)`, `]`, `}`, or `>`). Nested pairs of the braces used in the expansion are
|
||
allowed, but they must be balanced. Braces other than the ones used in the
|
||
expansion need not be balanced, however. For example, `%{nest{ed} non[nested}`
|
||
is valid and expands to `nest{ed} non[nested`.
|
||
|
||
If any other character is used, the expansion will end at the next occurrence of
|
||
that character. The quoting character can be escaped inside the expansion if it
|
||
is doubled-up. For example, `%|abc||def|` expands to the text `abc|def`.
|
||
|
||
It doesn't matter which character is used, but `{}` are most common.
|
||
|
||
There are 2 types of quoting which can be used to group together words separated
|
||
by whitespace into a single argument or prevent expansions from expanding:
|
||
|
||
"double quoted strings"::
|
||
Double quoted strings are mainly for grouping multiple `%` expansions or
|
||
`%` expansions and regular text as a single argument. `%` and `"` can be
|
||
escaped by doubling the characters (i.e. `%%` and `""`).
|
||
|
||
'single quoted strings'::
|
||
Expansions are not processed inside single quoted strings. Single quotes can
|
||
be escaped by doubling up (i.e. `''`).
|
||
|
||
Expansions are processed when unquoted and anywhere inside double-quoted
|
||
strings, but not inside unquoted words, inside single-quoted strings, or
|
||
inside %-strings or other expansions (see
|
||
<<command-parsing#typed-expansions, `:doc command-parsing typed-expansions`>>
|
||
for full details). For example:
|
||
|
||
* `echo %val{session}` echoes the current session ID
|
||
|
||
* `echo x%val{session}x` echoes the literal text `x%val{session}x`
|
||
|
||
* `echo '%val{session}'` echoes the literal text `%val{session}`
|
||
|
||
* `echo "x%val{session}x"` echoes the current session ID, surrounded by `x`
|
||
|
||
* `echo %{%val{session}}"` echoes the the literal text `%val{session}`
|
||
|
||
* `echo %sh{ echo %val{session} }"` echoes the literal text `%val{session}`
|
||
|
||
Like "variable expansion" and "command substitution" in shell programming,
|
||
Kakoune expansions can expand to multiple "words" - that is, separate
|
||
arguments on the resulting command-line. However, unlike shell programming,
|
||
Kakoune expansions cannot _accidentally_ expand to multiple words because they
|
||
contain whitespace or other special characters. Only expansions which
|
||
semantically contain a list of values (list-type options, registers, selections,
|
||
etc.) expand to multiple arguments. While in shell-programming it's good
|
||
practice to always wrap expansions in double-quotes, in Kakoune it's perfectly
|
||
safe to leave expansions unquoted.
|
||
|
||
== Argument expansions
|
||
|
||
Expansions with the type `arg` can only be used inside the "commands" parameter
|
||
of the `define-command` command (See <<commands#declaring-new-commands,`:doc
|
||
commands declaring-new-commands`>>).
|
||
|
||
The following expansions are available:
|
||
|
||
*%arg{n}*::
|
||
(where _n_ is a decimal number) +
|
||
expands to argument number _n_ of the current command
|
||
|
||
*%arg{@}*::
|
||
expands to all the arguments of the current command, as individual words
|
||
|
||
== Option expansions
|
||
|
||
Expansions with the type `opt` expand to the value associated with the named
|
||
option in the current scope (See <<options#,`:doc options`>>).
|
||
|
||
For example, `%opt{BOM}` expands to `utf8` or to `none`, according to the
|
||
current state of the `BOM` option.
|
||
|
||
== Register expansions
|
||
|
||
Expansions with the type `reg` expand to the contents of the named
|
||
register. For registers named after symbols (like the search register
|
||
`/`), the expansion can use either the symbol or the alphabetic name (See
|
||
<<registers#,`:doc registers`>>).
|
||
|
||
For example, `%reg{/}` expands to the content of the `/` register, and so does
|
||
`%reg{slash}`.
|
||
|
||
== Shell expansions
|
||
|
||
Expansions with the type `sh` are executed as shell-scripts, and whatever
|
||
the script prints to standard output replaces the expansion. For example,
|
||
the command `echo %sh{date}` will echo the output of the `date` command.
|
||
|
||
TIP: If a shell expansion writes to standard error, that output is appended to
|
||
Kakoune's `\*debug*` buffer. If you're trying to debug a shell expansion,
|
||
check the debug buffer with `:buffer \*debug*` to see if anything shows up.
|
||
|
||
Because Kakoune does not expand expansions inside the text of an expansion,
|
||
you can't use normal expansions inside `%sh{}`. Instead, Kakoune can export
|
||
expansions as environment variables to make them available to the shell.
|
||
Here's how expansion patterns map to variable names:
|
||
|
||
*%arg{n}*::
|
||
(where _n_ is a decimal number) +
|
||
becomes `$_n_`. For example, `%arg{3}` becomes `$3`.
|
||
|
||
*%arg{@}*::
|
||
becomes `$@`
|
||
|
||
*%opt{x}*::
|
||
becomes `$kak_opt_x`
|
||
|
||
*%reg{x}*::
|
||
(where _x_ is the alphabetic name of a register) +
|
||
`$kak_reg_x` contains all the selections in register _x_ +
|
||
`$kak_main_reg_x` contains only the main selection
|
||
|
||
*%val{x}*::
|
||
becomes `$kak_x`
|
||
|
||
When turned into environment variables, list-type options, `$kak_reg_x`, and
|
||
"quoted list" values will be shell-quoted so the shell doesn't get confused
|
||
about how many items the list contains. You will need to apply `eval` to get
|
||
back the original values. For example, if you want to process the contents
|
||
of each selection, you can do something like:
|
||
|
||
----
|
||
eval set -- "$kak_selections"
|
||
while [ $# -gt 0 ]; do
|
||
# ... do a thing with $1 ...
|
||
shift
|
||
done
|
||
----
|
||
|
||
The `eval` command will take the expanded `$kak_selections` and unquote them,
|
||
then execute the resulting `set` command, which sets the shell's argument
|
||
variables to the items from `$kak_selections`. The `while` loop with `shift`
|
||
iterates through the arguments one by one.
|
||
|
||
Only variables actually mentioned in the body of the shell expansion will
|
||
be exported into the shell's environment. For example:
|
||
|
||
----
|
||
echo %sh{ env | grep ^kak_ }
|
||
----
|
||
|
||
... will find none of Kakoune's special environment variables, but:
|
||
|
||
----
|
||
echo %sh{ env | grep ^kak_ # kak_session }
|
||
----
|
||
|
||
... will find the `$kak_session` variable because it was mentioned by name
|
||
in a comment, even though it wasn't directly used.
|
||
|
||
TIP: These environment variables are also available in other contexts where
|
||
Kakoune uses a shell command, such as the `|`, `!` or `$` normal mode commands
|
||
(See <<keys#,`:doc keys`>>).
|
||
|
||
== File expansions
|
||
|
||
Expansions with the type `file` will expand to the content of the filename
|
||
given in argument as read from the host filesystem.
|
||
|
||
== Value expansions
|
||
|
||
Expansions with the type `val` give access to Kakoune internal data that is
|
||
not stored in an option or a register. Some value expansions can only be used
|
||
in certain contexts, like `%val{hook_param}` that expands to the parameter
|
||
string of the currently-executing hook, and is not available outside a hook.
|
||
|
||
The following expansions are supported (with required context _in italics_):
|
||
|
||
*%val{buffile}*::
|
||
_in buffer, window scope_ +
|
||
full path of the file or same as `%val{bufname}` when there’s no
|
||
associated file
|
||
|
||
*%val{buf_line_count}*::
|
||
_in buffer, window scope_ +
|
||
number of lines in the current buffer
|
||
|
||
*%val{buflist}*::
|
||
quoted list of the names of currently-open buffers (as seen in
|
||
`%val{bufname}`)
|
||
|
||
*%val{bufname}*::
|
||
_in buffer, window scope_ +
|
||
name of the current buffer
|
||
|
||
*%val{client_env_X}*::
|
||
_in window scope_ +
|
||
value of the `$X` environment variable in the client displaying the current
|
||
window (e.g. `%val{client_env_SHELL}` is `$SHELL` in the client's
|
||
environment)
|
||
|
||
*%val{client_list}*::
|
||
unquoted list of the names of clients (as seen in `%val{client}`)
|
||
connected to the current session
|
||
|
||
*%val{client}*::
|
||
_in window scope_ +
|
||
name of the client displaying the current window
|
||
|
||
*%val{client_pid}*::
|
||
_in window scope_ +
|
||
process id of the client displaying the current window
|
||
|
||
*%val{config}*::
|
||
directory containing the user configuration
|
||
|
||
*%val{count}*::
|
||
_in `map` command <keys> parameter and `<a-;>` from object menu_ +
|
||
current count when the mapping was triggered, defaults to 0 if no
|
||
count given
|
||
|
||
*%val{cursor_byte_offset}*::
|
||
_in window scope_ +
|
||
offset of the main cursor from the beginning of the buffer (in bytes)
|
||
|
||
*%val{cursor_char_column}*::
|
||
_in window scope_ +
|
||
1-based offset from the start of the line to the cursor position in
|
||
Unicode codepoints, which may differ from visible columns if the document
|
||
contains full-width codepoints (which occupy two columns) or zero-width
|
||
codepoints
|
||
|
||
*%val{cursor_display_column}*::
|
||
_in window scope_ +
|
||
1-based offset from the start of the line to the cursor position in
|
||
display column, taking into account tabs and character width.
|
||
|
||
*%val{cursor_char_value}*::
|
||
_in window scope_ +
|
||
unicode value of the codepoint under the main cursor
|
||
|
||
*%val{cursor_column}*::
|
||
_in window scope_ +
|
||
1-based offset from the start of the line to the first byte of the
|
||
character under the main cursor (in bytes), the fourth component of
|
||
`%val{selection_desc}`
|
||
|
||
*%val{cursor_line}*::
|
||
_in window scope_ +
|
||
line of the main cursor, the third component of `%val{selection_desc}`
|
||
|
||
*%val{error}*::
|
||
_in `try` command's <on_error_commands> parameter_ +
|
||
the text of the error that cancelled execution of the <commands> parameter
|
||
(or the previous <on_error_commands> parameter)
|
||
|
||
*%val{history_id}*::
|
||
_in buffer, window scope_ +
|
||
history id of the current buffer, an integer value which refers to a
|
||
specific buffer version in the undo tree (see also `%val{timestamp}`)
|
||
|
||
*%val{hook_param_capture_n}*::
|
||
_in `hook` command <command> parameter_ +
|
||
text captured by capture group _n_, if the executing hook's filter regex
|
||
used capture groups
|
||
|
||
*%val{hook_param}*::
|
||
_in `hook` command <command> parameter_ +
|
||
the complete parameter string of the executing hook
|
||
|
||
*%val{modified}*::
|
||
_in buffer, window scope_ +
|
||
`true` if the buffer has modifications not saved, otherwise `false`
|
||
|
||
*%val{object_flags}*::
|
||
_for commands executed from the object menu's `<a-;>` only_ +
|
||
a pipe-separted list of words including `inner` if the user wants
|
||
an inner selection, `to_begin` if the user wants to select to the
|
||
beginning, and `to_end` if the user wants to select to the end
|
||
|
||
*%val{register}*::
|
||
_in `map` command <keys> parameter and `<a-;>` from the object menu_ +
|
||
current register when the mapping was triggered
|
||
|
||
*%val{runtime}*::
|
||
directory containing the kak support files, determined from Kakoune's
|
||
binary location
|
||
|
||
*%val{select_mode}*::
|
||
_for commands executed from the object menu's `<a-;>` only_ +
|
||
`replace` if the new selection should replace the existing, `extend`
|
||
otherwise
|
||
|
||
*%val{selection}*::
|
||
_in window scope_ +
|
||
content of the main selection
|
||
|
||
*%val{selections}*::
|
||
_in window scope_ +
|
||
quoted list of the contents of all selections
|
||
|
||
*%val{selection_desc}*::
|
||
_in window scope_ +
|
||
range of the main selection, represented as `a.b,c.d` where _a_ is the
|
||
anchor line, _b_ is the number of bytes from the start of the line to the
|
||
anchor, _c_ is the cursor line (like `%val{cursor_line}`), _d_ is
|
||
the number of bytes from the start of the line to the cursor (like
|
||
`%val{cursor_column}`), and all are 1-based decimal integers
|
||
|
||
*%val{selections_desc}*::
|
||
_in window scope_ +
|
||
unquoted list of the ranges of all selections, in the same format as
|
||
`%val{selection_desc}`
|
||
|
||
*%val{selection_length}*::
|
||
_in window scope_ +
|
||
length (in codepoints) of the main selection
|
||
|
||
*%val{selections_length}*::
|
||
_in window scope_ +
|
||
unquoted list of the lengths (in codepoints) of the selections
|
||
|
||
*%val{session}*::
|
||
name of the current session
|
||
|
||
*%val{source}*::
|
||
_in `.kak` file_ +
|
||
path of the file currently getting executed (through the source command)
|
||
|
||
*%val{text}*::
|
||
_in `prompt` command <command> parameter_ +
|
||
the text entered by the user in response to the `prompt` command
|
||
|
||
*%val{timestamp}*::
|
||
_in buffer, window scope_ +
|
||
timestamp of the current buffer, an integer that increments each time the
|
||
buffer is modified, including undoing and redoing previous modifications
|
||
(see also `%val{history_id}`)
|
||
|
||
*%val{user_modes}*::
|
||
unquoted list of user modes.
|
||
|
||
*%val{version}*::
|
||
version of the current Kakoune server (git hash or release name)
|
||
|
||
*%val{window_height}*::
|
||
_in window scope_ +
|
||
height of the current Kakoune window
|
||
|
||
*%val{window_width}*::
|
||
_in window scope_ +
|
||
width of the current Kakoune window
|
||
|
||
Values in the above list that do not mention a context are available
|
||
everywhere.
|
||
|
||
A value described as a "quoted list" will follow the rules of Kakoune string
|
||
quoting (See <<command-parsing#,`:doc command-parsing`>>). An "unquoted list"
|
||
cannot contain any special characters that would require quoting.
|