*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 language is builtin and always available. Try this command to get an idea of what lurks beneath: > :lua print(vim.inspect(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. A good overview of using Lua in neovim is given by https://github.com/nanotee/nvim-lua-guide. The |:source| and |:runtime| commands can run Lua scripts as well as Vim scripts. Lua modules can be loaded with `require('name')`, which conventionally returns a table but can return any value. See |lua-require| for details on how Nvim finds and loads Lua modules. See |lua-require-example| for an example of how to write and use a module. ============================================================================== IMPORTING LUA MODULES *lua-require* 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 on `require()`, see the Lua documentation at https://www.lua.org/manual/5.1/manual.html#pdf-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: 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 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 (defined at compile-time or derived from `$LUA_CPATH`/`$LUA_INIT`) |package.cpath| 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: > 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. ============================================================================== Lua Syntax Information *lua-syntax-help* While Lua has a simple syntax, there are a few things to understand, particularly when looking at the documentation above. *lua-syntax-call-function* Lua functions can be called in multiple ways. Consider the function: > local example_func = function(a, b) print("A is: ", a) print("B is: ", b) end < The first way to call this function is: > example_func(1, 2) -- ==== Result ==== -- A is: 1 -- B is: 2 < This way of calling a function is familiar from most scripting languages. In Lua, it's important to understand that any function arguments that are not supplied are automatically set to `nil`. For example: > example_func(1) -- ==== Result ==== -- A is: 1 -- B is: nil < Additionally, if any extra parameters are passed, they are discarded completely. In Lua, it is also possible to omit the parentheses (only) if the function takes a single string or table literal (`"foo"` or "`{1,2,3}`", respectively). The latter is most often used to approximate "keyword-style" arguments with a single dictionary, for example: > 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" } < In this style, each "parameter" is passed via keyword. It is still valid to call the function in the standard style: > func_with_opts({ foo = true, filename = "hello.world" }) < But often in the documentation, you will see the former rather than the latter style due to its brevity. ============================================================================== Lua Patterns *lua-patterns* For performance reasons, Lua does not support regular expressions natively. Instead, the Lua `string` standard library allows manipulations using a restricted set of "patterns", see |luaref-patterns|. Examples (`string.match` extracts the first match): > 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 For more complex matching, Vim regular expressions can be used from Lua through |vim.regex()|. ------------------------------------------------------------------------------ LUA PLUGIN EXAMPLE *lua-require-example* The following example plugin adds a command `:MakeCharBlob` which transforms current buffer into a long `unsigned char` array. Lua contains transformation function in a module `lua/charblob.lua` which is imported in `autoload/charblob.vim` (`require("charblob")`). Example plugin is supposed to be put into any directory from 'runtimepath', e.g. `~/.config/nvim` (in this case `lua/charblob.lua` means `~/.config/nvim/lua/charblob.lua`). autoload/charblob.vim: > function charblob#encode_buffer() call setline(1, luaeval( \ 'require("charblob").encode(unpack(_A))', \ [getline(1, '$'), &textwidth, ' '])) endfunction < plugin/charblob.vim: > if exists('g:charblob_loaded') finish endif let g:charblob_loaded = 1 command MakeCharBlob :call charblob#encode_buffer() < lua/charblob.lua: > local function charblob_bytes_iter(lines) local init_s = { next_line_idx = 1, next_byte_idx = 1, lines = lines, } local function next(s, _) if lines[s.next_line_idx] == nil then return nil end if s.next_byte_idx > #(lines[s.next_line_idx]) then s.next_line_idx = s.next_line_idx + 1 s.next_byte_idx = 1 return ('\n'):byte() end local ret = lines[s.next_line_idx]:byte(s.next_byte_idx) if ret == ('\n'):byte() then ret = 0 -- See :h NL-used-for-NUL. end s.next_byte_idx = s.next_byte_idx + 1 return ret end return next, init_s, nil end local function charblob_encode(lines, textwidth, indent) local ret = { 'const unsigned char blob[] = {', indent, } for byte in charblob_bytes_iter(lines) do -- .- space + number (width 3) + comma if #(ret[#ret]) + 5 > textwidth then ret[#ret + 1] = indent else ret[#ret] = ret[#ret] .. ' ' end ret[#ret] = ret[#ret] .. (('%3u,'):format(byte)) end ret[#ret + 1] = '};' return ret end return { bytes_iter = charblob_bytes_iter, encode = charblob_encode, } < ============================================================================== 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 |lua-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 {chunk} Executes Lua chunk {chunk}. If {chunk} starts with "=" the rest of the chunk is evaluated as an expression and printed. `:lua =expr` is equivalent to `:lua print(vim.inspect(expr))` Examples: > :lua vim.api.nvim_command('echo "Hello, Nvim!"') < To see the Lua version: > :lua print(_VERSION) < To see the LuaJIT version: > :lua =jit.version < *:lua-heredoc* :lua << [endmarker] {script} {endmarker} Executes Lua script {script} from within Vimscript. {endmarker} must NOT be preceded by whitespace. You can omit [endmarker] after the "<<" and use a dot "." after {script} (similar to |:append|, |:insert|). Example: > 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("Current 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 ), 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: > :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: > :luafile script.lua :luafile % < ============================================================================== luaeval() *lua-eval* *luaeval()* 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: > 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: > :echo luaeval('_A[1] + _A[2]', [40, 2]) 42 :echo luaeval('string.match(_A, "[a-z]+")', 'XYXfoo123') foo < 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: 0. Empty table is empty list. 1. Table with N incrementally growing integral numbers, starting from 1 and ending with N is considered to be a list. 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: > :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 > v:lua.func(arg1, arg2) is equivalent to the Lua chunk > return func(...) where the args are converted to Lua values. The expression > v:lua.somemod.func(args) is equivalent to the Lua chunk > return somemod.func(...) In addition, functions of packages can be accessed like > v:lua.require'mypack'.func(arg1, arg2) 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: > 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: > function mymod.omnifunc(findstart, base) if findstart == 1 then return 0 else return {'stuff', 'steam', 'strange things'} end end vim.api.nvim_buf_set_option(0, 'omnifunc', 'v:lua.mymod.omnifunc') Note: The module ("mymod" in the above example) must either be a Lua global, or use the require syntax as specified 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: > 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: > :lua print(vim.inspect(vim)) Result is something like this: > { _os_proc_children = , _os_proc_info = , ... api = { nvim__id = , nvim__id_array = , ... }, deepcopy = , gsplit = , ... } To find documentation on e.g. the "deepcopy" function: > :help vim.deepcopy() Note that underscore-prefixed functions (e.g. "_os_proc_children") are internal/private and must not be used by plugins. ------------------------------------------------------------------------------ VIM.LOOP *lua-loop* *vim.loop* `vim.loop` exposes all features of the Nvim event-loop. This is a low-level API that provides functionality for networking, filesystem, and process management. Try this command to see available functions: > :lua print(vim.inspect(vim.loop)) < Internally, `vim.loop` wraps the "luv" Lua bindings for the LibUV library; see |luv-intro| for a full reference manual. *E5560* *lua-loop-callbacks* It is an error to directly invoke `vim.api` functions (except |api-fast|) in `vim.loop` callbacks. For example, this is an error: > local timer = vim.loop.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: > local timer = vim.loop.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 %". > -- Create a timer handle (implementation detail: uv_timer_t). local timer = vim.loop.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|). > local w = vim.loop.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(''))") < 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"): > local function create_server(host, port, on_connect) local server = vim.loop.new_tcp() server:bind(host, port) server:listen(128, function(err) assert(not err, err) -- Check for errors. local sock = vim.loop.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.loop.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.loop` 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 |lua-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 *lua-highlight* Nvim includes a function for highlighting a selection on yank (see for example https://github.com/machakann/vim-highlightedyank). To enable it, add > au TextYankPost * silent! lua vim.highlight.on_yank() < to your `init.vim`. You can customize the highlight group and the duration of the highlight via > au TextYankPost * silent! lua vim.highlight.on_yank {higroup="IncSearch", timeout=150} < If you want to exclude visual selections from highlighting on yank, use > au TextYankPost * silent! lua vim.highlight.on_yank {on_visual=false} < vim.highlight.on_yank({opts}) *vim.highlight.on_yank()* Highlights the yanked text. The fields of the optional dict {opts} control the highlight: - {higroup} highlight group for yanked region (default |hl-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 |v:event|) vim.highlight.range({bufnr}, {ns}, {hlgroup}, {start}, {finish}, {opts}) *vim.highlight.range()* Apply highlight group to range of text. Parameters: ~ {bufnr} buffer number {ns} namespace for highlights {hlgroup} highlight group name {start} starting position (tuple {line,col}) {finish} finish position (tuple {line,col}) {opts} optional parameters: • `regtype`: type of range (characterwise, linewise, or blockwise, see |setreg|), default `'v'` • `inclusive`: range includes end position, default `false` • `priority`: priority of highlight, default `vim.highlight.user` (see below) vim.highlight.priorities *vim.highlight.priorities* Table with default priorities used for highlighting: • `syntax`: `50`, used for standard syntax highlighting • `treesitter`: `100`, used for tree-sitter-based 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.REGEX *lua-regex* Vim regexes can be used directly from lua. Currently they only allow matching within a single line. vim.regex({re}) *vim.regex()* Parse the Vim regex {re} and return a regex object. Regexes are "magic" and case-sensitive by default, regardless of 'magic' and 'ignorecase'. They can be controlled with flags, see |/magic| and |/ignorecase|. Methods on the regex object: regex:match_str({str}) *regex:match_str()* Match the string against the regex. If the string should match the regex precisely, surround the regex with `^` and `$`. If the was a match, the byte indices for the beginning and end of the match is returned. When there is no match, `nil` is returned. As any integer is truth-y, `regex:match()` can be directly used as a condition in an if-statement. regex:match_line({bufnr}, {line_idx} [, {start}, {end}]) *regex:match_line()* Match line {line_idx} (zero-based) in buffer {bufnr}. If {start} and {end} are supplied, match only this byte index range. Otherwise see |regex:match_str()|. If {start} is used, then the returned byte indices will be relative {start}. ------------------------------------------------------------------------------ VIM.DIFF *lua-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: > 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} First string to compare {b} Second string to compare {opts} 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. • `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: ~ See {opts.result_type}. nil if {opts.on_hunk} is given. ------------------------------------------------------------------------------ VIM.MPACK *lua-mpack* The *vim.mpack* module provides encoding and decoding of Lua objects to and from msgpack-encoded strings. Supports |vim.NIL| and |vim.empty_dict()|. vim.mpack.encode({obj}) *vim.mpack.encode* Encodes (or "packs") Lua object {obj} as msgpack in a Lua string. vim.mpack.decode({str}) *vim.mpack.decode* Decodes (or "unpacks") the msgpack-encoded {str} to a Lua object. ------------------------------------------------------------------------------ VIM.SPELL *lua-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: > vim.spell.check("the quik brown fox") --> { {'quik', 'bad', 4} } < Parameters: ~ {str} String to spell check. Return: ~ 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 *lua-builtin* vim.api.{func}({...}) *vim.api* Invokes Nvim |API| function {func} with arguments {...}. Example: call the "nvim_get_current_line()" API function: > print(tostring(vim.api.nvim_get_current_line())) vim.version() *vim.version* Gets the version of the current Nvim build. 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.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.empty_dict() *vim.empty_dict()* Creates a special empty table (marked with a metatable), which Nvim 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. 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|. 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 vim.stricmp({a}, {b}) *vim.stricmp()* Compares strings case-insensitively. Returns 0, 1 or -1 if strings are equal, {a} is greater than {b} or {a} is lesser than {b}, respectively. vim.str_utfindex({str} [, {index}]) *vim.str_utfindex()* Convert byte index to UTF-32 and UTF-16 indices. If {index} is not supplied, the length of the string is used. All indices are zero-based. Returns two values: the UTF-32 and UTF-16 indices respectively. Embedded NUL bytes are treated as terminating the string. Invalid UTF-8 bytes, and embedded surrogates are counted as one code point each. An {index} in the middle of a UTF-8 sequence is rounded upwards to the end of that sequence. 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. 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} (string) Encoding of {str} {to} (string) Target encoding Returns: ~ Converted string if conversion succeeds, `nil` otherwise. vim.schedule({callback}) *vim.schedule()* Schedules {callback} to be invoked soon by the main event-loop. Useful to avoid |textlock| or other temporary restrictions. vim.defer_fn({fn}, {timeout}) *vim.defer_fn* Defers calling {fn} until {timeout} ms passes. Use to do a one-shot timer that calls {fn}. Note: The {fn} is |schedule_wrap|ped automatically, so API functions are safe to call. Parameters: ~ {fn} Callback to call once {timeout} expires {timeout} Time in ms to wait before calling {fn} Returns: ~ |vim.loop|.new_timer() object vim.wait({time} [, {callback}, {interval}, {fast_only}]) *vim.wait()* Wait for {time} in milliseconds until {callback} returns `true`. Executes {callback} immediately and at approximately {interval} milliseconds (default 200). Nvim still processes other events during this time. Parameters: ~ {time} Number of milliseconds to wait {callback} Optional callback. Waits until {callback} returns true {interval} (Approximate) number of milliseconds to wait between polls {fast_only} If true, only |api-fast| events will be processed. If called from while in an |api-fast| event, will automatically be set to `true`. Returns: ~ If {callback} returns `true` during the {time}: `true, nil` If {callback} never returns `true` during the {time}: `false, -1` If {callback} is interrupted during the {time}: `false, -2` If {callback} errors, the error is raised. Examples: > --- -- Wait for 100 ms, allowing other events to process vim.wait(100, function() end) --- -- Wait for 100 ms or until global variable set. vim.wait(100, function() return vim.g.waiting_for_var end) --- -- Wait for 1 second or until global variable set, checking every ~500 ms vim.wait(1000, function() return vim.g.waiting_for_var end, 500) --- -- Schedule a function to set a value in 100ms vim.defer_fn(function() vim.g.timer_result = true end, 100) -- Would wait ten seconds if results blocked. Actually only waits 100 ms if vim.wait(10000, function() return vim.g.timer_result end) then print('Only waiting a little bit of time!') end < 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: > { [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 ------------------------------------------------------------------------------ LUA-VIMSCRIPT BRIDGE *lua-vimscript* Nvim Lua provides an interface to Vimscript variables and functions, and editor commands and options. See also https://github.com/nanotee/nvim-lua-guide. vim.call({func}, {...}) *vim.call()* Invokes |vim-function| or |user-function| {func} with arguments {...}. See also |vim.fn|. Equivalent to: > vim.fn[func]({...}) vim.cmd({command}) See |vim.cmd()|. vim.fn.{func}({...}) *vim.fn* Invokes |vim-function| or |user-function| {func} with arguments {...}. To call autoload functions, use the syntax: > vim.fn['some#function']({...}) < Unlike vim.api.|nvim_call_function()| this converts directly between Vim objects and Lua objects. If the Vim function returns a float, it will be represented directly as a Lua number. Empty lists and dictionaries both are represented by an empty table. Note: |v:null| values as part of the return value is represented as |vim.NIL| special value Note: vim.fn keys are generated lazily, thus `pairs(vim.fn)` only enumerates functions that were called at least once. Note: The majority of functions cannot run in |api-fast| callbacks with some undocumented exceptions which are allowed. *lua-vim-variables* The Vim editor global dictionaries |g:| |w:| |b:| |t:| |v:| can be accessed from Lua conveniently and idiomatically by referencing the `vim.*` Lua tables described below. In this way you can easily read and modify global Vimscript variables from Lua. Example: > vim.g.foo = 5 -- Set the g:foo Vimscript variable. print(vim.g.foo) -- Get and print the g:foo Vimscript variable. vim.g.foo = nil -- Delete (:unlet) the Vimscript variable. vim.b[2].foo = 6 -- Set b:foo for buffer 2 < vim.g *vim.g* Global (|g:|) editor variables. Key with no value returns `nil`. vim.b *vim.b* Buffer-scoped (|b:|) variables for the current buffer. Invalid or unset key returns `nil`. Can be indexed with an integer to access variables for a specific buffer. vim.w *vim.w* Window-scoped (|w:|) variables for the current window. Invalid or unset key returns `nil`. Can be indexed with an integer to access variables for a specific window. vim.t *vim.t* Tabpage-scoped (|t:|) variables for the current tabpage. Invalid or unset key returns `nil`. Can be indexed with an integer to access variables for a specific tabpage. vim.v *vim.v* |v:| variables. Invalid or unset key returns `nil`. vim.env *vim.env* Environment variables defined in the editor session. See |expand-env| and |:let-environment| for the Vimscript behavior. Invalid or unset key returns `nil`. Example: > vim.env.FOO = 'bar' print(vim.env.TERM) < *lua-options* *lua-vim-options* *lua-vim-set* *lua-vim-setlocal* Vim options can be accessed through |vim.o|, which behaves like Vimscript |:set|. Examples: ~ To set a boolean toggle: In Vimscript: `set number` In Lua: `vim.o.number = true` To set a string value: In Vimscript: `set wildignore=*.o,*.a,__pycache__` In Lua: `vim.o.wildignore = '*.o,*.a,__pycache__'` Similarly, there exist |vim.bo| and |vim.wo| for setting buffer-local and window-local options, respectively, similarly to |:setlocal|. There is also |vim.go| that only sets the global value of a |global-local| option, see |:setglobal|. The following table summarizes this relation. lua command global_value local_value ~ vim.o :set set set vim.bo/vim.wo :setlocal - set vim.go :setglobal set - vim.o *vim.o* Get or set editor options, like |:set|. Invalid key is an error. Example: > vim.o.cmdheight = 4 print(vim.o.columns) print(vim.o.foo) -- error: invalid key < vim.go *vim.go* Get or set an |option|. Invalid key is an error. This is a wrapper around |nvim_set_option_value()| and |nvim_get_option_value()|. NOTE: This is different from |vim.o| because this ONLY sets the global option, which generally produces confusing behavior for options with |global-local| values. Example: > vim.go.cmdheight = 4 print(vim.go.columns) print(vim.go.bar) -- error: invalid key < vim.bo[{bufnr}] *vim.bo* Get or set buffer-scoped |local-options| for the buffer with number {bufnr}. If [{bufnr}] is omitted, use the current buffer. Invalid {bufnr} or key is an error. This is a wrapper around |nvim_set_option_value()| and |nvim_get_option_value()| with `opts = {scope = local, buf = bufnr}` . Example: > local bufnr = vim.api.nvim_get_current_buf() vim.bo[bufnr].buflisted = true -- same as vim.bo.buflisted = true print(vim.bo.comments) print(vim.bo.baz) -- error: invalid key < vim.wo[{winid}] *vim.wo* Get or set window-scoped |local-options| for the window with handle {winid}. If [{winid}] is omitted, use the current window. Invalid {winid} or key is an error. This is a wrapper around |nvim_set_option_value()| and |nvim_get_option_value()| with `opts = {scope = local, win = winid}` . Example: > local winid = vim.api.nvim_get_current_win() vim.wo[winid].number = true -- same as vim.wo.number = true print(vim.wo.foldmarker) print(vim.wo.quux) -- error: invalid key < *lua-vim-opt* *lua-vim-optlocal* *lua-vim-optglobal* *vim.opt* A special interface |vim.opt| exists for conveniently interacting with list- and map-style option from Lua: It allows accessing them as Lua tables and offers object-oriented method for adding and removing entries. Examples: ~ The following methods of setting a list-style option are equivalent: In Vimscript: `set wildignore=*.o,*.a,__pycache__` In Lua using `vim.o`: `vim.o.wildignore = '*.o,*.a,__pycache__'` In Lua using `vim.opt`: `vim.opt.wildignore = { '*.o', '*.a', '__pycache__' }` To replicate the behavior of |:set+=|, use: > vim.opt.wildignore:append { "*.pyc", "node_modules" } < To replicate the behavior of |:set^=|, use: > vim.opt.wildignore:prepend { "new_first_value" } < To replicate the behavior of |:set-=|, use: > vim.opt.wildignore:remove { "node_modules" } < The following methods of setting a map-style option are equivalent: In Vimscript: `set listchars=space:_,tab:>~` In Lua using `vim.o`: `vim.o.listchars = 'space:_,tab:>~'` In Lua using `vim.opt`: `vim.opt.listchars = { space = '_', tab = '>~' }` Note that |vim.opt| returns an `Option` object, not the value of the option, which is accessed through |Option:get()|: Examples: ~ The following methods of getting a list-style option are equivalent: In Vimscript: `echo wildignore` In Lua using `vim.o`: `print(vim.o.wildignore)` In Lua using `vim.opt`: `vim.pretty_print(vim.opt.wildignore:get())` In any of the above examples, to replicate the behavior |setlocal|, use `vim.opt_local`. Additionally, to replicate the behavior of |setglobal|, use `vim.opt_global`. *vim.opt:get()* Option:get() Returns a lua-representation of the option. Boolean, number and string values will be returned in exactly the same fashion. For values that are comma-separated lists, an array will be returned with the values as entries in the array: > vim.cmd [[set wildignore=*.pyc,*.o]] vim.pretty_print(vim.opt.wildignore:get()) -- { "*.pyc", "*.o", } for _, ignore_pattern in ipairs(vim.opt.wildignore:get()) do print("Will ignore:", ignore_pattern) end -- Will ignore: *.pyc -- Will ignore: *.o < For values that are comma-separated maps, a table will be returned with the names as keys and the values as entries: > vim.cmd [[set listchars=space:_,tab:>~]] vim.pretty_print(vim.opt.listchars:get()) -- { space = "_", tab = ">~", } for char, representation in pairs(vim.opt.listchars:get()) do print(char, "->", representation) end < For values that are lists of flags, a set will be returned with the flags as keys and `true` as entries. > vim.cmd [[set formatoptions=njtcroql]] vim.pretty_print(vim.opt.formatoptions:get()) -- { n = true, j = true, c = true, ... } local format_opts = vim.opt.formatoptions:get() if format_opts.j then print("J is enabled!") end < *vim.opt:append()* Option:append(value) Append a value to string-style options. See |:set+=| These are equivalent: `vim.opt.formatoptions:append('j')` `vim.opt.formatoptions = vim.opt.formatoptions + 'j'` *vim.opt:prepend()* Option:prepend(value) Prepend a value to string-style options. See |:set^=| These are equivalent: `vim.opt.wildignore:prepend('*.o')` `vim.opt.wildignore = vim.opt.wildignore ^ '*.o'` *vim.opt:remove()* Option:remove(value) Remove a value from string-style options. See |:set-=| These are equivalent: `vim.opt.wildignore:remove('*.pyc')` `vim.opt.wildignore = vim.opt.wildignore - '*.pyc'` ============================================================================== Lua module: vim *lua-vim* cmd({command}) *vim.cmd()* Execute Vim script commands. Note that `vim.cmd` can be indexed with a command name to return a callable function to the command. Example: > vim.cmd('echo 42') vim.cmd([[ augroup My_group autocmd! autocmd FileType c setlocal cindent augroup END ]]) -- Ex command :echo "foo" -- Note string literals need to be double quoted. vim.cmd('echo "foo"') vim.cmd { cmd = 'echo', args = { '"foo"' } } vim.cmd.echo({ args = { '"foo"' } }) vim.cmd.echo('"foo"') -- Ex command :write! myfile.txt vim.cmd('write! myfile.txt') vim.cmd { cmd = 'write', args = { "myfile.txt" }, bang = true } vim.cmd.write { args = { "myfile.txt" }, bang = true } vim.cmd.write { "myfile.txt", bang = true } -- Ex command :colorscheme blue vim.cmd('colorscheme blue') vim.cmd.colorscheme('blue') < Parameters: ~ {command} string|table Command(s) to execute. If a string, executes multiple lines of Vim script at once. In this case, it is an alias to |nvim_exec()|, where `output` is set to false. Thus it works identical to |:source|. If a table, executes a single command. In this case, it is an alias to |nvim_cmd()| where `opts` is empty. See also: ~ |ex-cmd-index| *vim.connection_failure_errmsg()* connection_failure_errmsg({consequence}) TODO: Documentation defer_fn({fn}, {timeout}) *vim.defer_fn()* Defers calling `fn` until `timeout` ms passes. Use to do a one-shot timer that calls `fn` Note: The {fn} is |schedule_wrap|ped automatically, so API functions are safe to call. Parameters: ~ {fn} Callback to call once `timeout` expires {timeout} Number of milliseconds to wait before calling `fn` Return: ~ timer luv timer object *vim.deprecate()* deprecate({name}, {alternative}, {version}, {plugin}, {backtrace}) Display a deprecation notification to the user. Parameters: ~ {name} string Deprecated function. {alternative} (string|nil) Preferred alternative function. {version} string Version in which the deprecated function will be removed. {plugin} string|nil Plugin name that the function will be removed from. Defaults to "Nvim". {backtrace} boolean|nil Prints backtrace. Defaults to true. inspect({object}, {options}) *vim.inspect()* Return a human-readable representation of the given object. See also: ~ https://github.com/kikito/inspect.lua https://github.com/mpeterv/vinspect notify({msg}, {level}, {opts}) *vim.notify()* Display a notification to the user. This function can be overridden by plugins to display notifications using a custom provider (such as the system notification provider). By default, writes to |:messages|. Parameters: ~ {msg} (string) Content of the notification to show to the user. {level} (number|nil) One of the values from |vim.log.levels|. {opts} (table|nil) Optional parameters. Unused by default. notify_once({msg}, {level}, {opts}) *vim.notify_once()* Display a notification only one time. Like |vim.notify()|, but subsequent calls with the same message will not display a notification. Parameters: ~ {msg} (string) Content of the notification to show to the user. {level} (number|nil) One of the values from |vim.log.levels|. {opts} (table|nil) Optional parameters. Unused by default. Return: ~ (boolean) true if message was displayed, else false on_key({fn}, {ns_id}) *vim.on_key()* Adds Lua function {fn} with namespace id {ns_id} as a listener to every, yes every, input key. The Nvim command-line option |-w| is related but does not support callbacks and cannot be toggled dynamically. Note: {fn} will not be cleared by |nvim_buf_clear_namespace()| Note: {fn} will receive the keys after mappings have been evaluated Parameters: ~ {fn} function: Callback function. It should take one string argument. On each key press, Nvim passes the key char to fn(). |i_CTRL-V| If {fn} is nil, it removes the callback for the associated {ns_id} {ns_id} number? Namespace ID. If nil or 0, generates and returns a new |nvim_create_namespace()| id. Return: ~ (number) Namespace id associated with {fn}. Or count of all callbacks if on_key() is called without arguments. Note: {fn} will be removed if an error occurs while calling. paste({lines}, {phase}) *vim.paste()* Paste handler, invoked by |nvim_paste()| when a conforming UI (such as the |TUI|) pastes text into the editor. Example: To remove ANSI color codes when pasting: > vim.paste = (function(overridden) return function(lines, phase) for i,line in ipairs(lines) do -- Scrub ANSI color codes from paste input. lines[i] = line:gsub('\27%[[0-9;mK]+', '') end overridden(lines, phase) end end)(vim.paste) < Parameters: ~ {lines} |readfile()|-style list of lines to paste. |channel-lines| {phase} -1: "non-streaming" paste: the call contains all lines. If paste is "streamed", `phase` indicates the stream state: • 1: starts the paste (exactly once) • 2: continues the paste (zero or more times) • 3: ends the paste (exactly once) Return: ~ false if client should cancel the paste. See also: ~ |paste| pretty_print({...}) *vim.pretty_print()* Prints given arguments in human-readable format. Example: > -- Print highlight group Normal and store it's contents in a variable. local hl_normal = vim.pretty_print(vim.api.nvim_get_hl_by_name("Normal", true)) < Return: ~ given arguments. See also: ~ |vim.inspect()| region({bufnr}, {pos1}, {pos2}, {regtype}, {inclusive}) *vim.region()* Get a table of lines with start, end columns for a region marked by two points Parameters: ~ {bufnr} (number) of buffer {pos1} (line, column) tuple marking beginning of region {pos2} (line, column) tuple marking end of region {regtype} type of selection (:help setreg) {inclusive} (boolean) indicating whether the selection is end-inclusive Return: ~ region lua table of the form {linenr = {startcol,endcol}} schedule_wrap({cb}) *vim.schedule_wrap()* Defers callback `cb` until the Nvim API is safe to call. See also: ~ |lua-loop-callbacks| |vim.schedule()| |vim.in_fast_event()| deep_equal({a}, {b}) *vim.deep_equal()* Deep compare values for equality Tables are compared recursively unless they both provide the `eq` metamethod. All other types are compared using the equality `==` operator. Parameters: ~ {a} any First value {b} any Second value Return: ~ (boolean) `true` if values are equals, else `false` deepcopy({orig}) *vim.deepcopy()* Returns a deep copy of the given object. Non-table objects are copied as in a typical Lua assignment, whereas table objects are copied recursively. Functions are naively copied, so functions in the copied table point to the same functions as those in the input table. Userdata and threads are not copied and will throw an error. Parameters: ~ {orig} (table) Table to copy Return: ~ (table) Table of copied keys and (nested) values. endswith({s}, {suffix}) *vim.endswith()* Tests if `s` ends with `suffix`. Parameters: ~ {s} (string) String {suffix} (string) Suffix to match Return: ~ (boolean) `true` if `suffix` is a suffix of `s` gsplit({s}, {sep}, {plain}) *vim.gsplit()* Splits a string at each instance of a separator. Parameters: ~ {s} (string) String to split {sep} (string) Separator or pattern {plain} (boolean) If `true` use `sep` literally (passed to string.find) Return: ~ (function) Iterator over the split components See also: ~ |vim.split()| https://www.lua.org/pil/20.2.html http://lua-users.org/wiki/StringLibraryTutorial is_callable({f}) *vim.is_callable()* Returns true if object `f` can be called as a function. Parameters: ~ {f} any Any object Return: ~ (boolean) `true` if `f` is callable, else `false` list_extend({dst}, {src}, {start}, {finish}) *vim.list_extend()* Extends a list-like table with the values of another list-like table. NOTE: This mutates dst! Parameters: ~ {dst} (table) List which will be modified and appended to {src} (table) List from which values will be inserted {start} (number) Start index on src. Defaults to 1 {finish} (number) Final index on src. Defaults to `#src` Return: ~ (table) dst See also: ~ |vim.tbl_extend()| list_slice({list}, {start}, {finish}) *vim.list_slice()* Creates a copy of a table containing only elements from start to end (inclusive) Parameters: ~ {list} (table) Table {start} (number) Start range of slice {finish} (number) End range of slice Return: ~ (table) Copy of table sliced from start to finish (inclusive) pesc({s}) *vim.pesc()* Escapes magic chars in |lua-patterns|. Parameters: ~ {s} (string) String to escape Return: ~ (string) %-escaped pattern string See also: ~ https://github.com/rxi/lume split({s}, {sep}, {kwargs}) *vim.split()* Splits a string at each instance of a separator. Examples: > split(":aa::b:", ":") --> {'','aa','','b',''} split("axaby", "ab?") --> {'','x','y'} split("x*yz*o", "*", {plain=true}) --> {'x','yz','o'} split("|x|y|z|", "|", {trimempty=true}) --> {'x', 'y', 'z'} < Parameters: ~ {s} (string) String to split {sep} (string) Separator or pattern {kwargs} (table) Keyword arguments: • plain: (boolean) If `true` use `sep` literally (passed to string.find) • trimempty: (boolean) If `true` remove empty items from the front and back of the list Return: ~ (table) List of split components See also: ~ |vim.gsplit()| startswith({s}, {prefix}) *vim.startswith()* Tests if `s` starts with `prefix`. Parameters: ~ {s} (string) String {prefix} (string) Prefix to match Return: ~ (boolean) `true` if `prefix` is a prefix of `s` tbl_add_reverse_lookup({o}) *vim.tbl_add_reverse_lookup()* Add the reverse lookup values to an existing table. For example: `tbl_add_reverse_lookup { A = 1 } == { [1] = 'A', A = 1 }` Note that this modifies the input. Parameters: ~ {o} (table) Table to add the reverse to Return: ~ (table) o tbl_contains({t}, {value}) *vim.tbl_contains()* Checks if a list-like (vector) table contains `value`. Parameters: ~ {t} (table) Table to check {value} any Value to compare Return: ~ (boolean) `true` if `t` contains `value` tbl_count({t}) *vim.tbl_count()* Counts the number of non-nil values in table `t`. > vim.tbl_count({ a=1, b=2 }) => 2 vim.tbl_count({ 1, 2 }) => 2 < Parameters: ~ {t} (table) Table Return: ~ (number) Number of non-nil values in table See also: ~ https://github.com/Tieske/Penlight/blob/master/lua/pl/tablex.lua tbl_deep_extend({behavior}, {...}) *vim.tbl_deep_extend()* Merges recursively two or more map-like tables. Parameters: ~ {behavior} (string) Decides what to do if a key is found in more than one map: • "error": raise an error • "keep": use value from the leftmost map • "force": use value from the rightmost map {...} (table) Two or more map-like tables Return: ~ (table) Merged table See also: ~ |tbl_extend()| tbl_extend({behavior}, {...}) *vim.tbl_extend()* Merges two or more map-like tables. Parameters: ~ {behavior} (string) Decides what to do if a key is found in more than one map: • "error": raise an error • "keep": use value from the leftmost map • "force": use value from the rightmost map {...} (table) Two or more map-like tables Return: ~ (table) Merged table See also: ~ |extend()| tbl_filter({func}, {t}) *vim.tbl_filter()* Filter a table using a predicate function Parameters: ~ {func} function|table Function or callable table {t} (table) Table Return: ~ (table) Table of filtered values tbl_flatten({t}) *vim.tbl_flatten()* Creates a copy of a list-like table such that any nested tables are "unrolled" and appended to the result. Parameters: ~ {t} (table) List-like table Return: ~ (table) Flattened copy of the given list-like table See also: ~ From https://github.com/premake/premake-core/blob/master/src/base/table.lua tbl_get({o}, {...}) *vim.tbl_get()* Index into a table (first argument) via string keys passed as subsequent arguments. Return `nil` if the key does not exist. Examples: > vim.tbl_get({ key = { nested_key = true }}, 'key', 'nested_key') == true vim.tbl_get({ key = {}}, 'key', 'nested_key') == nil < Parameters: ~ {o} (table) Table to index {...} (string) Optional strings (0 or more, variadic) via which to index the table Return: ~ any Nested value indexed by key (if it exists), else nil tbl_isempty({t}) *vim.tbl_isempty()* Checks if a table is empty. Parameters: ~ {t} (table) Table to check Return: ~ (boolean) `true` if `t` is empty See also: ~ https://github.com/premake/premake-core/blob/master/src/base/table.lua tbl_islist({t}) *vim.tbl_islist()* Tests if a Lua table can be treated as an array. Empty table `{}` is assumed to be an array, unless it was created by |vim.empty_dict()| or returned as a dict-like |API| or Vimscript result, for example from |rpcrequest()| or |vim.fn|. Parameters: ~ {t} (table) Table Return: ~ (boolean) `true` if array-like table, else `false` tbl_keys({t}) *vim.tbl_keys()* Return a list of all keys used in a table. However, the order of the return table of keys is not guaranteed. Parameters: ~ {t} (table) Table Return: ~ (table) List of keys See also: ~ From https://github.com/premake/premake-core/blob/master/src/base/table.lua tbl_map({func}, {t}) *vim.tbl_map()* Apply a function to all values of a table. Parameters: ~ {func} function|table Function or callable table {t} (table) Table Return: ~ (table) Table of transformed values tbl_values({t}) *vim.tbl_values()* Return a list of all values used in a table. However, the order of the return table of values is not guaranteed. Parameters: ~ {t} (table) Table Return: ~ (table) List of values trim({s}) *vim.trim()* Trim whitespace (Lua pattern "%s") from both sides of a string. Parameters: ~ {s} (string) String to trim Return: ~ (string) String with whitespace removed from its beginning and end See also: ~ https://www.lua.org/pil/20.2.html validate({opt}) *vim.validate()* Validates a parameter specification (types and values). Usage example: > function user.new(name, age, hobbies) vim.validate{ name={name, 'string'}, age={age, 'number'}, hobbies={hobbies, 'table'}, } ... end < Examples with explicit argument values (can be run directly): > vim.validate{arg1={{'foo'}, 'table'}, arg2={'foo', 'string'}} => NOP (success) vim.validate{arg1={1, 'table'}} => error('arg1: expected table, got number') vim.validate{arg1={3, function(a) return (a % 2) == 0 end, 'even number'}} => error('arg1: expected even number, got 3') < If multiple types are valid they can be given as a list. > vim.validate{arg1={{'foo'}, {'table', 'string'}}, arg2={'foo', {'table', 'string'}}} => NOP (success) vim.validate{arg1={1, {'string', table'}}} => error('arg1: expected string|table, got number') < Parameters: ~ {opt} (table) Names of parameters to validate. Each key is a parameter name; each value is a tuple in one of these forms: 1. (arg_value, type_name, optional) • arg_value: argument value • type_name: string|table type name, one of: ("table", "t", "string", "s", "number", "n", "boolean", "b", "function", "f", "nil", "thread", "userdata") or list of them. • optional: (optional) boolean, if true, `nil` is valid 2. (arg_value, fn, msg) • arg_value: argument value • fn: any function accepting one argument, returns true if and only if the argument is valid. Can optionally return an additional informative error message as the second returned value. • msg: (optional) error string if validation fails ============================================================================== Lua module: uri *lua-uri* uri_from_bufnr({bufnr}) *vim.uri_from_bufnr()* Get a URI from a bufnr Parameters: ~ {bufnr} (number) Return: ~ (string) URI uri_from_fname({path}) *vim.uri_from_fname()* Get a URI from a file path. Parameters: ~ {path} (string) Path to file Return: ~ (string) URI uri_to_bufnr({uri}) *vim.uri_to_bufnr()* Get the buffer for a uri. Creates a new unloaded buffer if no buffer for the uri already exists. Parameters: ~ {uri} (string) Return: ~ (number) bufnr uri_to_fname({uri}) *vim.uri_to_fname()* Get a filename from a URI Parameters: ~ {uri} (string) Return: ~ (string) filename or unchanged URI for non-file URIs ============================================================================== Lua module: ui *lua-ui* input({opts}, {on_confirm}) *vim.ui.input()* Prompts the user for input Example: > vim.ui.input({ prompt = 'Enter value for shiftwidth: ' }, function(input) vim.o.shiftwidth = tonumber(input) end) < Parameters: ~ {opts} (table) Additional options. See |input()| • prompt (string|nil) Text of the prompt • default (string|nil) Default reply to the input • completion (string|nil) Specifies type of completion supported for input. Supported types are the same that can be supplied to a user-defined command using the "-complete=" argument. See |:command-completion| • highlight (function) Function that will be used for highlighting user inputs. {on_confirm} (function) ((input|nil) -> ()) Called once the user confirms or abort the input. `input` is what the user typed. `nil` if the user aborted the dialog. select({items}, {opts}, {on_choice}) *vim.ui.select()* Prompts the user to pick a single item from a collection of entries Example: > vim.ui.select({ 'tabs', 'spaces' }, { prompt = 'Select tabs or spaces:', format_item = function(item) return "I'd like to choose " .. item end, }, function(choice) if choice == 'spaces' then vim.o.expandtab = true else vim.o.expandtab = false end end) < Parameters: ~ {items} (table) Arbitrary items {opts} (table) Additional options • prompt (string|nil) Text of the prompt. Defaults to `Select one of:` • format_item (function item -> text) Function to format an individual item from `items`. Defaults to `tostring`. • kind (string|nil) Arbitrary hint string indicating the item shape. Plugins reimplementing `vim.ui.select` may wish to use this to infer the structure or semantics of `items`, or the context in which select() was called. {on_choice} (function) ((item|nil, idx|nil) -> ()) Called once the user made a choice. `idx` is the 1-based index of `item` within `items`. `nil` if the user aborted the dialog. ============================================================================== Lua module: filetype *lua-filetype* add({filetypes}) *vim.filetype.add()* Add new filetype mappings. Filetype mappings can be added either by extension or by filename (either the "tail" or the full file path). The full file path is checked first, followed by the file name. If a match is not found using the filename, then the filename is matched against the list of |lua-patterns| (sorted by priority) until a match is found. Lastly, if pattern matching does not find a filetype, then the file extension is used. The filetype can be either a string (in which case it is used as the filetype directly) or a function. If a function, it takes the full path and buffer number of the file as arguments (along with captures from the matched pattern, if any) and should return a string that will be used as the buffer's filetype. Optionally, the function can return a second function value which, when called, modifies the state of the buffer. This can be used to, for example, set filetype-specific buffer variables. Filename patterns can specify an optional priority to resolve cases when a file path matches multiple patterns. Higher priorities are matched first. When omitted, the priority defaults to 0. See $VIMRUNTIME/lua/vim/filetype.lua for more examples. Note that Lua filetype detection is disabled when |g:do_legacy_filetype| is set. Example: > vim.filetype.add({ extension = { foo = 'fooscript', bar = function(path, bufnr) if some_condition() then return 'barscript', function(bufnr) -- Set a buffer variable vim.b[bufnr].barscript_version = 2 end end return 'bar' end, }, filename = { ['.foorc'] = 'toml', ['/etc/foo/config'] = 'toml', }, pattern = { ['.*/etc/foo/.*'] = 'fooscript', -- Using an optional priority ['.*/etc/foo/.*%.conf'] = { 'dosini', { priority = 10 } }, ['README.(a+)$'] = function(path, bufnr, ext) if ext == 'md' then return 'markdown' elseif ext == 'rst' then return 'rst' end end, }, }) < To add a fallback match on contents (see |new-filetype-scripts|), use > vim.filetype.add { pattern = { ['.*'] = { priority = -math.huge, function(path, bufnr) local content = vim.filetype.getlines(bufnr, 1) if vim.filetype.matchregex(content, [[^#!.*\]]) then return 'mine' elseif vim.filetype.matchregex(content, [[\]]) then return 'drawing' end end, }, }, } < Parameters: ~ {filetypes} (table) A table containing new filetype maps (see example). match({args}) *vim.filetype.match()* Perform filetype detection. The filetype can be detected using one of three methods: 1. Using an existing buffer 2. Using only a file name 3. Using only file contents Of these, option 1 provides the most accurate result as it uses both the buffer's filename and (optionally) the buffer contents. Options 2 and 3 can be used without an existing buffer, but may not always provide a match in cases where the filename (or contents) cannot unambiguously determine the filetype. Each of the three options is specified using a key to the single argument of this function. Example: > -- Using a buffer number vim.filetype.match({ buf = 42 }) -- Override the filename of the given buffer vim.filetype.match({ buf = 42, filename = 'foo.c' }) -- Using a filename without a buffer vim.filetype.match({ filename = 'main.lua' }) -- Using file contents vim.filetype.match({ contents = {'#!/usr/bin/env bash'} }) < Parameters: ~ {args} (table) Table specifying which matching strategy to use. Accepted keys are: • buf (number): Buffer number to use for matching. Mutually exclusive with {contents} • filename (string): Filename to use for matching. When {buf} is given, defaults to the filename of the given buffer number. The file need not actually exist in the filesystem. When used without {buf} only the name of the file is used for filetype matching. This may result in failure to detect the filetype in cases where the filename alone is not enough to disambiguate the filetype. • contents (table): An array of lines representing file contents to use for matching. Can be used with {filename}. Mutually exclusive with {buf}. Return: ~ (string|nil) If a match was found, the matched filetype. (function|nil) A function that modifies buffer state when called (for example, to set some filetype specific buffer variables). The function accepts a buffer number as its only argument. ============================================================================== Lua module: keymap *lua-keymap* del({modes}, {lhs}, {opts}) *vim.keymap.del()* Remove an existing mapping. Examples: > vim.keymap.del('n', 'lhs') vim.keymap.del({'n', 'i', 'v'}, 'w', { buffer = 5 }) < Parameters: ~ {opts} (table) A table of optional arguments: • buffer: (number or boolean) Remove a mapping from the given buffer. When "true" or 0, use the current buffer. See also: ~ |vim.keymap.set()| set({mode}, {lhs}, {rhs}, {opts}) *vim.keymap.set()* Add a new |mapping|. Examples: > -- Can add mapping to Lua functions vim.keymap.set('n', 'lhs', function() print("real lua function") end) -- Can use it to map multiple modes vim.keymap.set({'n', 'v'}, 'lr', vim.lsp.buf.references, { buffer=true }) -- Can add mapping for specific buffer vim.keymap.set('n', 'w', "w", { silent = true, buffer = 5 }) -- Expr mappings vim.keymap.set('i', '', function() return vim.fn.pumvisible() == 1 and "" or "" end, { expr = true }) -- mappings vim.keymap.set('n', '[%', '(MatchitNormalMultiBackward)') < Note that in a mapping like: > vim.keymap.set('n', 'asdf', require('jkl').my_fun) < the `require('jkl')` gets evaluated during this call in order to access the function. If you want to avoid this cost at startup you can wrap it in a function, for example: > vim.keymap.set('n', 'asdf', function() return require('jkl').my_fun() end) < Parameters: ~ {mode} string|table Same mode short names as |nvim_set_keymap()|. Can also be list of modes to create mapping on multiple modes. {lhs} (string) Left-hand side |{lhs}| of the mapping. {rhs} string|function Right-hand side |{rhs}| of the mapping. Can also be a Lua function. {opts} (table) A table of |:map-arguments|. • Accepts options accepted by the {opts} parameter in |nvim_set_keymap()|, with the following notable differences: • replace_keycodes: Defaults to `true` if "expr" is `true`. • noremap: Always overridden with the inverse of "remap" (see below). • In addition to those options, the table accepts the following keys: • buffer: (number or boolean) Add a mapping to the given buffer. When `0` or `true`, use the current buffer. • remap: (boolean) Make the mapping recursive. This is the inverse of the "noremap" option from |nvim_set_keymap()|. Defaults to `false`. See also: ~ |nvim_set_keymap()| ============================================================================== Lua module: fs *lua-fs* basename({file}) *vim.fs.basename()* Return the basename of the given file or directory Parameters: ~ {file} (string) File or directory Return: ~ (string) Basename of {file} dir({path}) *vim.fs.dir()* Return an iterator over the files and directories located in {path} Parameters: ~ {path} (string) An absolute or relative path to the directory to iterate over. The path is first normalized |vim.fs.normalize()|. Return: ~ Iterator over files and directories in {path}. Each iteration yields two values: name and type. Each "name" is the basename of the file or directory relative to {path}. Type is one of "file" or "directory". dirname({file}) *vim.fs.dirname()* Return the parent directory of the given file or directory Parameters: ~ {file} (string) File or directory Return: ~ (string) Parent directory of {file} find({names}, {opts}) *vim.fs.find()* Find files or directories in the given path. Finds any files or directories given in {names} starting from {path}. If {upward} is "true" then the search traverses upward through parent directories; otherwise, the search traverses downward. Note that downward searches are recursive and may search through many directories! If {stop} is non-nil, then the search stops when the directory given in {stop} is reached. The search terminates when {limit} (default 1) matches are found. The search can be narrowed to find only files or or only directories by specifying {type} to be "file" or "directory", respectively. Parameters: ~ {names} (string|table) Names of the files and directories to find. Must be base names, paths and globs are not supported. {opts} (table) Optional keyword arguments: • path (string): Path to begin searching from. If omitted, the current working directory is used. • upward (boolean, default false): If true, search upward through parent directories. Otherwise, search through child directories (recursively). • stop (string): Stop searching when this directory is reached. The directory itself is not searched. • type (string): Find only files ("file") or directories ("directory"). If omitted, both files and directories that match {name} are included. • limit (number, default 1): Stop the search after finding this many matches. Use `math.huge` to place no limit on the number of matches. Return: ~ (table) The paths of all matching files or directories normalize({path}) *vim.fs.normalize()* Normalize a path to a standard format. A tilde (~) character at the beginning of the path is expanded to the user's home directory and any backslash (\) characters are converted to forward slashes (/). Environment variables are also expanded. Example: > vim.fs.normalize('C:\Users\jdoe') => 'C:/Users/jdoe' vim.fs.normalize('~/src/neovim') => '/home/jdoe/src/neovim' vim.fs.normalize('$XDG_CONFIG_HOME/nvim/init.vim') => '/Users/jdoe/.config/nvim/init.vim' < Parameters: ~ {path} (string) Path to normalize Return: ~ (string) Normalized path parents({start}) *vim.fs.parents()* Iterate over all the parents of the given file or directory. Example: > local root_dir for dir in vim.fs.parents(vim.api.nvim_buf_get_name(0)) do if vim.fn.isdirectory(dir .. "/.git") == 1 then root_dir = dir break end end if root_dir then print("Found git repository at", root_dir) end < Parameters: ~ {start} (string) Initial file or directory. Return: ~ (function) Iterator vim:tw=78:ts=8:sw=4:sts=4:et:ft=help:norl: