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lua.txt
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lua.txt
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*lua.txt* Nvim
NVIM REFERENCE MANUAL
Lua engine *lua* *Lua*
Type |gO| to see the table of contents.
==============================================================================
INTRODUCTION *lua-intro*
The Lua 5.1 script engine is builtin and always available. Try this command to
get an idea of what lurks beneath: >vim
:lua vim.print(package.loaded)
Nvim includes a "standard library" |lua-stdlib| for Lua. It complements the
"editor stdlib" (|builtin-functions| and |Ex-commands|) and the |API|, all of
which can be used from Lua code (|lua-vimscript| |vim.api|). Together these
"namespaces" form the Nvim programming interface.
Lua plugins and user config are automatically discovered and loaded, just like
Vimscript. See |lua-guide| for practical guidance.
You can also run Lua scripts from your shell using the |-l| argument: >
nvim -l foo.lua [args...]
<
*lua-compat*
Lua 5.1 is the permanent interface for Nvim Lua. Plugins need only consider
Lua 5.1, not worry about forward-compatibility with future Lua versions. If
Nvim ever ships with Lua 5.4+, a Lua 5.1 compatibility shim will be provided
so that old plugins continue to work transparently.
*lua-luajit*
Nvim is built with luajit on platforms which support it, which provides
extra functionality. Lua code in |init.lua| and plugins can assume its presence
on installations on common platforms. For maximum compatibility with less
common platforms, availability can be checked using the `jit` global variable: >lua
if jit then
-- code for luajit
else
-- code for plain lua 5.1
end
<
*lua-bit*
In particular, the luajit "bit" extension module is _always_ available.
A fallback implementation is included when nvim is built with PUC Lua 5.1,
and will be transparently used when `require("bit")` is invoked.
==============================================================================
LUA CONCEPTS AND IDIOMS *lua-concepts*
Lua is very simple: this means that, while there are some quirks, once you
internalize those quirks, everything works the same everywhere. Scopes
(closures) in particular are very consistent, unlike JavaScript or most other
languages.
Lua has three fundamental mechanisms—one for "each major aspect of
programming": tables, closures, and coroutines.
https://www.lua.org/doc/cacm2018.pdf
- Tables are the "object" or container datastructure: they represent both
lists and maps, you can extend them to represent your own datatypes and
change their behavior using |metatable|s (like Python's "datamodel").
- EVERY scope in Lua is a closure: a function is a closure, a module is
a closure, a `do` block (|lua-do|) is a closure--and they all work the same.
A Lua module is literally just a big closure discovered on the "path"
(where your modules are found: |package.cpath|).
- Stackful coroutines enable cooperative multithreading, generators, and
versatile control for both Lua and its host (Nvim).
*iterator*
An iterator is just a function that can be called repeatedly to get the "next"
value of a collection (or any other |iterable|). This interface is expected by
|for-in| loops, produced by |pairs()|, supported by |vim.iter|, etc.
https://www.lua.org/pil/7.1.html
*iterable*
An "iterable" is anything that |vim.iter()| can consume: tables, dicts, lists,
iterator functions, tables implementing the |__call()| metamethod, and
|vim.iter()| objects.
*list-iterator*
Iterators on |lua-list| tables have a "middle" and "end", whereas iterators in
general may be logically infinite. Therefore some |vim.iter| operations (e.g.
|Iter:rev()|) make sense only on list-like tables (which are finite by
definition).
*lua-function-call*
Lua functions can be called in multiple ways. Consider the function: >lua
local foo = function(a, b)
print("A: ", a)
print("B: ", b)
end
The first way to call this function is: >lua
foo(1, 2)
-- ==== Result ====
-- A: 1
-- B: 2
This way of calling a function is familiar from most scripting languages. In
Lua, any missing arguments are passed as `nil`, and extra parameters are
silently discarded. Example: >lua
foo(1)
-- ==== Result ====
-- A: 1
-- B: nil
<
*kwargs*
When calling a function, you can omit the parentheses if the function takes
exactly one string literal (`"foo"`) or table literal (`{1,2,3}`). The latter
is often used to mimic "named parameters" ("kwargs" or "keyword args") as in
languages like Python and C#. Example: >lua
local func_with_opts = function(opts)
local will_do_foo = opts.foo
local filename = opts.filename
...
end
func_with_opts { foo = true, filename = "hello.world" }
<
There's nothing special going on here except that parentheses are implicitly
added. But visually, this small bit of sugar gets reasonably close to a
"keyword args" interface.
*lua-regex*
Lua intentionally does not support regular expressions, instead it has limited
|lua-patterns| which avoid the performance pitfalls of extended regex. Lua
scripts can also use Vim regex via |vim.regex()|.
Examples: >lua
print(string.match("foo123bar123", "%d+"))
-- 123
print(string.match("foo123bar123", "[^%d]+"))
-- foo
print(string.match("foo123bar123", "[abc]+"))
-- ba
print(string.match("foo.bar", "%.bar"))
-- .bar
==============================================================================
IMPORTING LUA MODULES *lua-module-load*
Modules are searched for under the directories specified in 'runtimepath', in
the order they appear. Any "." in the module name is treated as a directory
separator when searching. For a module `foo.bar`, each directory is searched
for `lua/foo/bar.lua`, then `lua/foo/bar/init.lua`. If no files are found,
the directories are searched again for a shared library with a name matching
`lua/foo/bar.?`, where `?` is a list of suffixes (such as `so` or `dll`) derived from
the initial value of |package.cpath|. If still no files are found, Nvim falls
back to Lua's default search mechanism. The first script found is run and
`require()` returns the value returned by the script if any, else `true`.
The return value is cached after the first call to `require()` for each module,
with subsequent calls returning the cached value without searching for, or
executing any script. For further details see |require()|.
For example, if 'runtimepath' is `foo,bar` and |package.cpath| was
`./?.so;./?.dll` at startup, `require('mod')` searches these paths in order
and loads the first module found ("first wins"): >
foo/lua/mod.lua
foo/lua/mod/init.lua
bar/lua/mod.lua
bar/lua/mod/init.lua
foo/lua/mod.so
foo/lua/mod.dll
bar/lua/mod.so
bar/lua/mod.dll
<
*lua-package-path*
Nvim automatically adjusts |package.path| and |package.cpath| according to the
effective 'runtimepath' value. Adjustment happens whenever 'runtimepath' is
changed. `package.path` is adjusted by simply appending `/lua/?.lua` and
`/lua/?/init.lua` to each directory from 'runtimepath' (`/` is actually the
first character of `package.config`).
Similarly to |package.path|, modified directories from 'runtimepath' are also
added to |package.cpath|. In this case, instead of appending `/lua/?.lua` and
`/lua/?/init.lua` to each runtimepath, all unique `?`-containing suffixes of
the existing |package.cpath| are used. Example:
- 1. Given that
- 'runtimepath' contains `/foo/bar,/xxx;yyy/baz,/abc`;
- initial |package.cpath| (defined at compile-time or derived from
`$LUA_CPATH` / `$LUA_INIT`) contains `./?.so;/def/ghi/a?d/j/g.elf;/def/?.so`.
- 2. It finds `?`-containing suffixes `/?.so`, `/a?d/j/g.elf` and `/?.so`, in
order: parts of the path starting from the first path component containing
question mark and preceding path separator.
- 3. The suffix of `/def/?.so`, namely `/?.so` is not unique, as it’s the same
as the suffix of the first path from |package.path| (i.e. `./?.so`). Which
leaves `/?.so` and `/a?d/j/g.elf`, in this order.
- 4. 'runtimepath' has three paths: `/foo/bar`, `/xxx;yyy/baz` and `/abc`. The
second one contains a semicolon which is a paths separator so it is out,
leaving only `/foo/bar` and `/abc`, in order.
- 5. The cartesian product of paths from 4. and suffixes from 3. is taken,
giving four variants. In each variant a `/lua` path segment is inserted
between path and suffix, leaving:
- `/foo/bar/lua/?.so`
- `/foo/bar/lua/a?d/j/g.elf`
- `/abc/lua/?.so`
- `/abc/lua/a?d/j/g.elf`
- 6. New paths are prepended to the original |package.cpath|.
The result will look like this: >
/foo/bar,/xxx;yyy/baz,/abc ('runtimepath')
× ./?.so;/def/ghi/a?d/j/g.elf;/def/?.so (package.cpath)
= /foo/bar/lua/?.so;/foo/bar/lua/a?d/j/g.elf;/abc/lua/?.so;/abc/lua/a?d/j/g.elf;./?.so;/def/ghi/a?d/j/g.elf;/def/?.so
Note:
- To track 'runtimepath' updates, paths added at previous update are
remembered and removed at the next update, while all paths derived from the
new 'runtimepath' are prepended as described above. This allows removing
paths when path is removed from 'runtimepath', adding paths when they are
added and reordering |package.path|/|package.cpath| content if 'runtimepath'
was reordered.
- Although adjustments happen automatically, Nvim does not track current
values of |package.path| or |package.cpath|. If you happen to delete some
paths from there you can set 'runtimepath' to trigger an update: >vim
let &runtimepath = &runtimepath
- Skipping paths from 'runtimepath' which contain semicolons applies both to
|package.path| and |package.cpath|. Given that there are some badly written
plugins using shell, which will not work with paths containing semicolons,
it is better to not have them in 'runtimepath' at all.
==============================================================================
COMMANDS *lua-commands*
These commands execute a Lua chunk from either the command line (:lua, :luado)
or a file (:luafile) on the given line [range]. As always in Lua, each chunk
has its own scope (closure), so only global variables are shared between
command calls. The |lua-stdlib| modules, user modules, and anything else on
|package.path| are available.
The Lua print() function redirects its output to the Nvim message area, with
arguments separated by " " (space) instead of "\t" (tab).
*:lua=* *:lua*
:lua {chunk}
Executes Lua chunk {chunk}. If {chunk} starts with "=" the rest of the
chunk is evaluated as an expression and printed. `:lua =expr` or `:=expr` is
equivalent to `:lua print(vim.inspect(expr))`.
Examples: >vim
:lua vim.api.nvim_command('echo "Hello, Nvim!"')
< To see the Lua version: >vim
:lua print(_VERSION)
< To see the LuaJIT version: >vim
:lua =jit.version
<
:{range}lua
Executes buffer lines in {range} as Lua code. Unlike |:source|, this
always treats the lines as Lua code.
Example: select the following code and type ":lua<Enter>" to execute it: >lua
print(string.format(
'unix time: %s', os.time()))
<
*:lua-heredoc*
:lua << [trim] [{endmarker}]
{script}
{endmarker}
Executes Lua script {script} from within Vimscript. You can omit
[endmarker] after the "<<" and use a dot "." after {script} (similar to
|:append|, |:insert|). Refer to |:let-heredoc| for more information.
Example: >vim
function! CurrentLineInfo()
lua << EOF
local linenr = vim.api.nvim_win_get_cursor(0)[1]
local curline = vim.api.nvim_buf_get_lines(0, linenr - 1, linenr, false)[1]
print(string.format('Line [%d] has %d bytes', linenr, #curline))
EOF
endfunction
<
Note that the `local` variables will disappear when the block finishes.
But not globals.
*:luado*
:[range]luado {body}
Executes Lua chunk "function(line, linenr) {body} end" for each buffer
line in [range], where `line` is the current line text (without <EOL>),
and `linenr` is the current line number. If the function returns a string
that becomes the text of the corresponding buffer line. Default [range] is
the whole file: "1,$".
Examples: >vim
:luado return string.format("%s\t%d", line:reverse(), #line)
:lua require"lpeg"
:lua -- balanced parenthesis grammar:
:lua bp = lpeg.P{ "(" * ((1 - lpeg.S"()") + lpeg.V(1))^0 * ")" }
:luado if bp:match(line) then return "=>\t" .. line end
<
*:luafile*
:luafile {file}
Execute Lua script in {file}.
The whole argument is used as the filename (like |:edit|), spaces do not
need to be escaped. Alternatively you can |:source| Lua files.
Examples: >vim
:luafile script.lua
:luafile %
<
==============================================================================
luaeval() *lua-eval*
The (dual) equivalent of "vim.eval" for passing Lua values to Nvim is
"luaeval". "luaeval" takes an expression string and an optional argument used
for _A inside expression and returns the result of the expression. It is
semantically equivalent in Lua to: >lua
local chunkheader = "local _A = select(1, ...) return "
function luaeval (expstr, arg)
local chunk = assert(loadstring(chunkheader .. expstr, "luaeval"))
return chunk(arg) -- return typval
end
<
Lua nils, numbers, strings, tables and booleans are converted to their
respective Vimscript types. If a Lua string contains a NUL byte, it will be
converted to a |Blob|. Conversion of other Lua types is an error.
The magic global "_A" contains the second argument to luaeval().
Example: >vim
:echo luaeval('_A[1] + _A[2]', [40, 2])
" 42
:echo luaeval('string.match(_A, "[a-z]+")', 'XYXfoo123')
" foo
<
*lua-table-ambiguous*
Lua tables are used as both dictionaries and lists, so it is impossible to
determine whether empty table is meant to be empty list or empty dictionary.
Additionally Lua does not have integer numbers. To distinguish between these
cases there is the following agreement:
*lua-list*
0. Empty table is empty list.
1. Table with N consecutive integer indices starting from 1 and ending with
N is considered a list. See also |list-iterator|.
*lua-dict*
2. Table with string keys, none of which contains NUL byte, is considered to
be a dictionary.
3. Table with string keys, at least one of which contains NUL byte, is also
considered to be a dictionary, but this time it is converted to
a |msgpack-special-map|.
*lua-special-tbl*
4. Table with `vim.type_idx` key may be a dictionary, a list or floating-point
value:
- `{[vim.type_idx]=vim.types.float, [vim.val_idx]=1}` is converted to
a floating-point 1.0. Note that by default integral Lua numbers are
converted to |Number|s, non-integral are converted to |Float|s. This
variant allows integral |Float|s.
- `{[vim.type_idx]=vim.types.dictionary}` is converted to an empty
dictionary, `{[vim.type_idx]=vim.types.dictionary, [42]=1, a=2}` is
converted to a dictionary `{'a': 42}`: non-string keys are ignored.
Without `vim.type_idx` key tables with keys not fitting in 1., 2. or 3.
are errors.
- `{[vim.type_idx]=vim.types.array}` is converted to an empty list. As well
as `{[vim.type_idx]=vim.types.array, [42]=1}`: integral keys that do not
form a 1-step sequence from 1 to N are ignored, as well as all
non-integral keys.
Examples: >vim
:echo luaeval('math.pi')
:function Rand(x,y) " random uniform between x and y
: return luaeval('(_A.y-_A.x)*math.random()+_A.x', {'x':a:x,'y':a:y})
: endfunction
:echo Rand(1,10)
<
Note: Second argument to `luaeval` is converted ("marshalled") from Vimscript
to Lua, so changes to Lua containers do not affect values in Vimscript. Return
value is also always converted. When converting, |msgpack-special-dict|s are
treated specially.
==============================================================================
Vimscript v:lua interface *v:lua-call*
From Vimscript the special `v:lua` prefix can be used to call Lua functions
which are global or accessible from global tables. The expression >vim
call v:lua.func(arg1, arg2)
is equivalent to the Lua chunk >lua
return func(...)
where the args are converted to Lua values. The expression >vim
call v:lua.somemod.func(args)
is equivalent to the Lua chunk >lua
return somemod.func(...)
In addition, functions of packages can be accessed like >vim
call v:lua.require'mypack'.func(arg1, arg2)
call v:lua.require'mypack.submod'.func(arg1, arg2)
Note: Only single quote form without parens is allowed. Using
`require"mypack"` or `require('mypack')` as prefixes do NOT work (the latter
is still valid as a function call of itself, in case require returns a useful
value).
The `v:lua` prefix may be used to call Lua functions as |method|s. For
example: >vim
:eval arg1->v:lua.somemod.func(arg2)
<
You can use `v:lua` in "func" options like 'tagfunc', 'omnifunc', etc.
For example consider the following Lua omnifunc handler: >lua
function mymod.omnifunc(findstart, base)
if findstart == 1 then
return 0
else
return {'stuff', 'steam', 'strange things'}
end
end
vim.bo[buf].omnifunc = 'v:lua.mymod.omnifunc'
Note: The module ("mymod" in the above example) must either be a Lua global,
or use require() as shown above to access it from a package.
Note: `v:lua` without a call is not allowed in a Vimscript expression:
|Funcref|s cannot represent Lua functions. The following are errors: >vim
let g:Myvar = v:lua.myfunc " Error
call SomeFunc(v:lua.mycallback) " Error
let g:foo = v:lua " Error
let g:foo = v:['lua'] " Error
<
==============================================================================
Lua standard modules *lua-stdlib*
The Nvim Lua "standard library" (stdlib) is the `vim` module, which exposes
various functions and sub-modules. It is always loaded, thus `require("vim")`
is unnecessary.
You can peek at the module properties: >vim
:lua vim.print(vim)
Result is something like this: >
{
_os_proc_children = <function 1>,
_os_proc_info = <function 2>,
...
api = {
nvim__id = <function 5>,
nvim__id_array = <function 6>,
...
},
deepcopy = <function 106>,
gsplit = <function 107>,
...
}
To find documentation on e.g. the "deepcopy" function: >vim
:help vim.deepcopy()
Note that underscore-prefixed functions (e.g. "_os_proc_children") are
internal/private and must not be used by plugins.
------------------------------------------------------------------------------
VIM.UV *lua-loop* *vim.uv*
`vim.uv` exposes the "luv" Lua bindings for the libUV library that Nvim uses
for networking, filesystem, and process management, see |luvref.txt|.
In particular, it allows interacting with the main Nvim |luv-event-loop|.
*E5560* *lua-loop-callbacks*
It is an error to directly invoke `vim.api` functions (except |api-fast|) in
`vim.uv` callbacks. For example, this is an error: >lua
local timer = vim.uv.new_timer()
timer:start(1000, 0, function()
vim.api.nvim_command('echomsg "test"')
end)
<
To avoid the error use |vim.schedule_wrap()| to defer the callback: >lua
local timer = vim.uv.new_timer()
timer:start(1000, 0, vim.schedule_wrap(function()
vim.api.nvim_command('echomsg "test"')
end))
<
(For one-shot timers, see |vim.defer_fn()|, which automatically adds the
wrapping.)
Example: repeating timer
1. Save this code to a file.
2. Execute it with ":luafile %". >lua
-- Create a timer handle (implementation detail: uv_timer_t).
local timer = vim.uv.new_timer()
local i = 0
-- Waits 1000ms, then repeats every 750ms until timer:close().
timer:start(1000, 750, function()
print('timer invoked! i='..tostring(i))
if i > 4 then
timer:close() -- Always close handles to avoid leaks.
end
i = i + 1
end)
print('sleeping');
<
Example: File-change detection *watch-file*
1. Save this code to a file.
2. Execute it with ":luafile %".
3. Use ":Watch %" to watch any file.
4. Try editing the file from another text editor.
5. Observe that the file reloads in Nvim (because on_change() calls
|:checktime|). >lua
local w = vim.uv.new_fs_event()
local function on_change(err, fname, status)
-- Do work...
vim.api.nvim_command('checktime')
-- Debounce: stop/start.
w:stop()
watch_file(fname)
end
function watch_file(fname)
local fullpath = vim.api.nvim_call_function(
'fnamemodify', {fname, ':p'})
w:start(fullpath, {}, vim.schedule_wrap(function(...)
on_change(...) end))
end
vim.api.nvim_command(
"command! -nargs=1 Watch call luaeval('watch_file(_A)', expand('<args>'))")
<
Example: TCP echo-server *tcp-server*
1. Save this code to a file.
2. Execute it with ":luafile %".
3. Note the port number.
4. Connect from any TCP client (e.g. "nc 0.0.0.0 36795"): >lua
local function create_server(host, port, on_connect)
local server = vim.uv.new_tcp()
server:bind(host, port)
server:listen(128, function(err)
assert(not err, err) -- Check for errors.
local sock = vim.uv.new_tcp()
server:accept(sock) -- Accept client connection.
on_connect(sock) -- Start reading messages.
end)
return server
end
local server = create_server('0.0.0.0', 0, function(sock)
sock:read_start(function(err, chunk)
assert(not err, err) -- Check for errors.
if chunk then
sock:write(chunk) -- Echo received messages to the channel.
else -- EOF (stream closed).
sock:close() -- Always close handles to avoid leaks.
end
end)
end)
print('TCP echo-server listening on port: '..server:getsockname().port)
<
Multithreading *lua-loop-threading*
Plugins can perform work in separate (os-level) threads using the threading
APIs in luv, for instance `vim.uv.new_thread`. Note that every thread
gets its own separate Lua interpreter state, with no access to Lua globals
in the main thread. Neither can the state of the editor (buffers, windows,
etc) be directly accessed from threads.
A subset of the `vim.*` API is available in threads. This includes:
- `vim.uv` with a separate event loop per thread.
- `vim.mpack` and `vim.json` (useful for serializing messages between threads)
- `require` in threads can use Lua packages from the global |package.path|
- `print()` and `vim.inspect`
- `vim.diff`
- most utility functions in `vim.*` for working with pure Lua values
like `vim.split`, `vim.tbl_*`, `vim.list_*`, and so on.
- `vim.is_thread()` returns true from a non-main thread.
==============================================================================
VIM.HIGHLIGHT *vim.highlight*
Nvim includes a function for highlighting a selection on yank.
To enable it, add the following to your `init.vim`: >vim
au TextYankPost * silent! lua vim.highlight.on_yank()
<
You can customize the highlight group and the duration of the highlight via: >vim
au TextYankPost * silent! lua vim.highlight.on_yank {higroup="IncSearch", timeout=150}
<
If you want to exclude visual selections from highlighting on yank, use: >vim
au TextYankPost * silent! lua vim.highlight.on_yank {on_visual=false}
<
vim.highlight.on_yank({opts}) *vim.highlight.on_yank()*
Highlight the yanked text
Parameters: ~
• {opts} (`table?`) Optional parameters
• higroup highlight group for yanked region (default
"IncSearch")
• timeout time in ms before highlight is cleared (default 150)
• on_macro highlight when executing macro (default false)
• on_visual highlight when yanking visual selection (default
true)
• event event structure (default vim.v.event)
• priority integer priority (default
|vim.highlight.priorities|`.user`)
vim.highlight.priorities *vim.highlight.priorities*
Table with default priorities used for highlighting:
• `syntax`: `50`, used for standard syntax highlighting
• `treesitter`: `100`, used for treesitter-based highlighting
• `semantic_tokens`: `125`, used for LSP semantic token highlighting
• `diagnostics`: `150`, used for code analysis such as diagnostics
• `user`: `200`, used for user-triggered highlights such as LSP document
symbols or `on_yank` autocommands
*vim.highlight.range()*
vim.highlight.range({bufnr}, {ns}, {higroup}, {start}, {finish}, {opts})
Apply highlight group to range of text.
Parameters: ~
• {bufnr} (`integer`) Buffer number to apply highlighting to
• {ns} (`integer`) Namespace to add highlight to
• {higroup} (`string`) Highlight group to use for highlighting
• {start} (`integer[]|string`) Start of region as a (line, column)
tuple or string accepted by |getpos()|
• {finish} (`integer[]|string`) End of region as a (line, column)
tuple or string accepted by |getpos()|
• {opts} (`table?`) Optional parameters
• regtype type of range (see |setreg()|, default charwise)
• inclusive boolean indicating whether the range is
end-inclusive (default false)
• priority number indicating priority of highlight (default
priorities.user)
==============================================================================
VIM.DIFF *vim.diff*
vim.diff({a}, {b}, {opts}) *vim.diff()*
Run diff on strings {a} and {b}. Any indices returned by this function,
either directly or via callback arguments, are 1-based.
Examples: >lua
vim.diff('a\n', 'b\nc\n')
-- =>
-- @@ -1 +1,2 @@
-- -a
-- +b
-- +c
vim.diff('a\n', 'b\nc\n', {result_type = 'indices'})
-- =>
-- {
-- {1, 1, 1, 2}
-- }
<
Parameters: ~
• {a} (`string`) First string to compare
• {b} (`string`) Second string to compare
• {opts} (`table<string,any>`) Optional parameters:
• `on_hunk` (callback): Invoked for each hunk in the diff.
Return a negative number to cancel the callback for any
remaining hunks. Args:
• `start_a` (integer): Start line of hunk in {a}.
• `count_a` (integer): Hunk size in {a}.
• `start_b` (integer): Start line of hunk in {b}.
• `count_b` (integer): Hunk size in {b}.
• `result_type` (string): Form of the returned diff:
• "unified": (default) String in unified format.
• "indices": Array of hunk locations. Note: This option is
ignored if `on_hunk` is used.
• `linematch` (boolean|integer): Run linematch on the
resulting hunks from xdiff. When integer, only hunks upto
this size in lines are run through linematch. Requires
`result_type = indices`, ignored otherwise.
• `algorithm` (string): Diff algorithm to use. Values:
• "myers" the default algorithm
• "minimal" spend extra time to generate the smallest
possible diff
• "patience" patience diff algorithm
• "histogram" histogram diff algorithm
• `ctxlen` (integer): Context length
• `interhunkctxlen` (integer): Inter hunk context length
• `ignore_whitespace` (boolean): Ignore whitespace
• `ignore_whitespace_change` (boolean): Ignore whitespace
change
• `ignore_whitespace_change_at_eol` (boolean) Ignore
whitespace change at end-of-line.
• `ignore_cr_at_eol` (boolean) Ignore carriage return at
end-of-line
• `ignore_blank_lines` (boolean) Ignore blank lines
• `indent_heuristic` (boolean): Use the indent heuristic for
the internal diff library.
Return: ~
(`string|table?`) See {opts.result_type}. `nil` if {opts.on_hunk} is
given.
==============================================================================
VIM.MPACK *vim.mpack*
This module provides encoding and decoding of Lua objects to and from
msgpack-encoded strings. Supports |vim.NIL| and |vim.empty_dict()|.
vim.mpack.decode({str}) *vim.mpack.decode()*
Decodes (or "unpacks") the msgpack-encoded {str} to a Lua object.
Parameters: ~
• {str} (`string`)
Return: ~
(`any`)
vim.mpack.encode({obj}) *vim.mpack.encode()*
Encodes (or "packs") Lua object {obj} as msgpack in a Lua string.
Parameters: ~
• {obj} (`any`)
Return: ~
(`string`)
==============================================================================
VIM.JSON *vim.json*
This module provides encoding and decoding of Lua objects to and from
JSON-encoded strings. Supports |vim.NIL| and |vim.empty_dict()|.
vim.json.decode({str}, {opts}) *vim.json.decode()*
Decodes (or "unpacks") the JSON-encoded {str} to a Lua object.
• Decodes JSON "null" as |vim.NIL| (controllable by {opts}, see below).
• Decodes empty object as |vim.empty_dict()|.
• Decodes empty array as `{}` (empty Lua table).
Example: >lua
vim.print(vim.json.decode('{"bar":[],"foo":{},"zub":null}'))
-- { bar = {}, foo = vim.empty_dict(), zub = vim.NIL }
<
Parameters: ~
• {str} (`string`) Stringified JSON data.
• {opts} (`table<string,any>?`) Options table with keys:
• luanil: (table) Table with keys:
• object: (boolean) When true, converts `null` in JSON
objects to Lua `nil` instead of |vim.NIL|.
• array: (boolean) When true, converts `null` in JSON arrays
to Lua `nil` instead of |vim.NIL|.
Return: ~
(`any`)
vim.json.encode({obj}) *vim.json.encode()*
Encodes (or "packs") Lua object {obj} as JSON in a Lua string.
Parameters: ~
• {obj} (`any`)
Return: ~
(`string`)
==============================================================================
VIM.BASE64 *vim.base64*
vim.base64.decode({str}) *vim.base64.decode()*
Decode a Base64 encoded string.
Parameters: ~
• {str} (`string`) Base64 encoded string
Return: ~
(`string`) Decoded string
vim.base64.encode({str}) *vim.base64.encode()*
Encode {str} using Base64.
Parameters: ~
• {str} (`string`) String to encode
Return: ~
(`string`) Encoded string
==============================================================================
VIM.SPELL *vim.spell*
vim.spell.check({str}) *vim.spell.check()*
Check {str} for spelling errors. Similar to the Vimscript function
|spellbadword()|.
Note: The behaviour of this function is dependent on: 'spelllang',
'spellfile', 'spellcapcheck' and 'spelloptions' which can all be local to
the buffer. Consider calling this with |nvim_buf_call()|.
Example: >lua
vim.spell.check("the quik brown fox")
-- =>
-- {
-- {'quik', 'bad', 5}
-- }
<
Parameters: ~
• {str} (`string`)
Return: ~
(`{[1]: string, [2]: string, [3]: string}[]`) List of tuples with
three items:
• The badly spelled word.
• The type of the spelling error: "bad" spelling mistake "rare" rare
word "local" word only valid in another region "caps" word should
start with Capital
• The position in {str} where the word begins.
==============================================================================
VIM *vim.builtin*
vim.api.{func}({...}) *vim.api*
Invokes Nvim |API| function {func} with arguments {...}.
Example: call the "nvim_get_current_line()" API function: >lua
print(tostring(vim.api.nvim_get_current_line()))
vim.NIL *vim.NIL*
Special value representing NIL in |RPC| and |v:null| in Vimscript
conversion, and similar cases. Lua `nil` cannot be used as part of a Lua
table representing a Dictionary or Array, because it is treated as
missing: `{"foo", nil}` is the same as `{"foo"}`.
vim.type_idx *vim.type_idx*
Type index for use in |lua-special-tbl|. Specifying one of the values from
|vim.types| allows typing the empty table (it is unclear whether empty Lua
table represents empty list or empty array) and forcing integral numbers
to be |Float|. See |lua-special-tbl| for more details.
vim.val_idx *vim.val_idx*
Value index for tables representing |Float|s. A table representing
floating-point value 1.0 looks like this: >lua
{
[vim.type_idx] = vim.types.float,
[vim.val_idx] = 1.0,
}
< See also |vim.type_idx| and |lua-special-tbl|.
vim.types *vim.types*
Table with possible values for |vim.type_idx|. Contains two sets of
key-value pairs: first maps possible values for |vim.type_idx| to
human-readable strings, second maps human-readable type names to values
for |vim.type_idx|. Currently contains pairs for `float`, `array` and
`dictionary` types.
Note: One must expect that values corresponding to `vim.types.float`,
`vim.types.array` and `vim.types.dictionary` fall under only two following
assumptions:
1. Value may serve both as a key and as a value in a table. Given the
properties of Lua tables this basically means “value is not `nil`”.
2. For each value in `vim.types` table `vim.types[vim.types[value]]` is the
same as `value`.
No other restrictions are put on types, and it is not guaranteed that
values corresponding to `vim.types.float`, `vim.types.array` and
`vim.types.dictionary` will not change or that `vim.types` table will only
contain values for these three types.
*log_levels* *vim.log.levels*
Log levels are one of the values defined in `vim.log.levels`:
vim.log.levels.DEBUG
vim.log.levels.ERROR
vim.log.levels.INFO
vim.log.levels.TRACE
vim.log.levels.WARN
vim.log.levels.OFF
vim.empty_dict() *vim.empty_dict()*
Creates a special empty table (marked with a metatable), which Nvim
converts to an empty dictionary when translating Lua values to Vimscript
or API types. Nvim by default converts an empty table `{}` without this
metatable to an list/array.
Note: If numeric keys are present in the table, Nvim ignores the metatable
marker and converts the dict to a list/array anyway.
Return: ~
(`table`)
vim.iconv({str}, {from}, {to}, {opts}) *vim.iconv()*
The result is a String, which is the text {str} converted from encoding
{from} to encoding {to}. When the conversion fails `nil` is returned. When
some characters could not be converted they are replaced with "?". The
encoding names are whatever the iconv() library function can accept, see
":Man 3 iconv".
Parameters: ~
• {str} (`string`) Text to convert
• {from} (`number`) Encoding of {str}
• {to} (`number`) Target encoding
• {opts} (`table<string,any>?`)
Return: ~
(`string?`) Converted string if conversion succeeds, `nil` otherwise.
vim.in_fast_event() *vim.in_fast_event()*
Returns true if the code is executing as part of a "fast" event handler,
where most of the API is disabled. These are low-level events (e.g.
|lua-loop-callbacks|) which can be invoked whenever Nvim polls for input.
When this is `false` most API functions are callable (but may be subject
to other restrictions such as |textlock|).
vim.rpcnotify({channel}, {method}, {args}, {...}) *vim.rpcnotify()*
Sends {event} to {channel} via |RPC| and returns immediately. If {channel}
is 0, the event is broadcast to all channels.
This function also works in a fast callback |lua-loop-callbacks|.
Parameters: ~
• {channel} (`integer`)
• {method} (`string`)
• {args} (`any[]?`)
• {...} (`any?`)
vim.rpcrequest({channel}, {method}, {args}, {...}) *vim.rpcrequest()*
Sends a request to {channel} to invoke {method} via |RPC| and blocks until
a response is received.
Note: NIL values as part of the return value is represented as |vim.NIL|
special value
Parameters: ~
• {channel} (`integer`)
• {method} (`string`)
• {args} (`any[]?`)
• {...} (`any?`)
vim.schedule({fn}) *vim.schedule()*
Schedules {fn} to be invoked soon by the main event-loop. Useful to avoid
|textlock| or other temporary restrictions.
Parameters: ~
• {fn} (`function`)
vim.str_byteindex({str}, {index}, {use_utf16}) *vim.str_byteindex()*
Convert UTF-32 or UTF-16 {index} to byte index. If {use_utf16} is not
supplied, it defaults to false (use UTF-32). Returns the byte index.
Invalid UTF-8 and NUL is treated like by |vim.str_byteindex()|. An {index}
in the middle of a UTF-16 sequence is rounded upwards to the end of that
sequence.
Parameters: ~
• {str} (`string`)
• {index} (`number`)
• {use_utf16} (`any?`)
vim.str_utf_end({str}, {index}) *vim.str_utf_end()*
Gets the distance (in bytes) from the last byte of the codepoint
(character) that {index} points to.
Examples: >lua
-- The character 'æ' is stored as the bytes '\xc3\xa6' (using UTF-8)
-- Returns 0 because the index is pointing at the last byte of a character
vim.str_utf_end('æ', 2)
-- Returns 1 because the index is pointing at the penultimate byte of a character
vim.str_utf_end('æ', 1)
<
Parameters: ~
• {str} (`string`)
• {index} (`number`)
Return: ~
(`number`)
vim.str_utf_pos({str}) *vim.str_utf_pos()*
Gets a list of the starting byte positions of each UTF-8 codepoint in the
given string.
Embedded NUL bytes are treated as terminating the string.
Parameters: ~
• {str} (`string`)
Return: ~