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Diffstat (limited to 'runtime/doc/if_lua.txt')
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diff --git a/runtime/doc/if_lua.txt b/runtime/doc/if_lua.txt index aa2d0a03c6..34bcf0f039 100644 --- a/runtime/doc/if_lua.txt +++ b/runtime/doc/if_lua.txt @@ -1,668 +1,8 @@ -*if_lua.txt* Nvim - NVIM REFERENCE MANUAL + 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" (|functions| and Ex commands) and the |API|, all of which can -be used from Lua code. - -Module conflicts are resolved by "last wins". For example if both of these -are on 'runtimepath': - runtime/lua/foo.lua - ~/.config/nvim/lua/foo.lua -then `require('foo')` loads "~/.config/nvim/lua/foo.lua", and -"runtime/lua/foo.lua" is not used. See |lua-require| to understand how Nvim -finds and loads Lua modules. The conventions are similar to VimL plugins, -with some extra features. See |lua-require-example| for a walkthrough. - -============================================================================== -Importing Lua modules *lua-require* - -Nvim automatically adjusts `package.path` and `package.cpath` according to -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 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 `/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 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* - - *:lua* -:[range]lua {chunk} - Execute Lua chunk {chunk}. - -Examples: -> - :lua vim.api.nvim_command('echo "Hello, Nvim!"') -< -To see the Lua version: > - :lua print(_VERSION) - -To see the LuaJIT version: > - :lua print(jit.version) -< - -:[range]lua << [endmarker] -{script} -{endmarker} - Execute Lua script {script}. Useful for including Lua - code in Vim scripts. - -The {endmarker} must NOT be preceded by any white space. - -If [endmarker] is omitted from after the "<<", a dot '.' must be used after -{script}, like for the |:append| and |:insert| commands. - -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, linenr + 1, false)[1] - print(string.format("Current line [%d] has %d bytes", - linenr, #curline)) - EOF - endfunction - -Note that the `local` variables will disappear when block finishes. This is -not the case for globals. - - *:luado* -:[range]luado {body} Execute Lua function "function (line, linenr) {body} - end" for each line in the [range], with the function - argument being set to the text of each line in turn, - without a trailing <EOL>, and the current line number. - If the value returned by the function is a string it - becomes the text of the line in the current turn. The - default for [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* -:[range]luafile {file} - Execute Lua script in {file}. - The whole argument is used as a single file name. - -Examples: -> - :luafile script.lua - :luafile % -< - -All these commands execute a Lua chunk from either the command line (:lua and -:luado) or a file (:luafile) with the given line [range]. Similarly to the Lua -interpreter, each chunk has its own scope and so only global variables are -shared between command calls. All Lua default libraries are available. In -addition, Lua "print" function has its output redirected to the Nvim message -area, with arguments separated by a white space instead of a tab. - -Lua uses the "vim" module (see |lua-vim|) to issue commands to Nvim. However, -procedures that alter buffer content, open new buffers, and change cursor -position are restricted when the command is executed in the |sandbox|. - - -============================================================================== -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 VimL types. An error is thrown if conversion of any other Lua types -is attempted. - -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.list}` is converted to an empty list. As well - as `{[vim.type_idx]=vim.types.list, [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 that currently second argument to `luaeval` undergoes VimL to lua -conversion, so changing containers in lua do not affect values in VimL. Return -value is also always converted. When converting, |msgpack-special-dict|s are -treated specially. - -============================================================================== -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 = <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: > - - :help vim.deepcopy - -Note that underscore-prefixed functions (e.g. "_os_proc_children") are -internal/private and must not be used by plugins. - ------------------------------------------------------------------------------- -VIM.API *lua-api* - -`vim.api` exposes the full Nvim |API| as a table of Lua functions. - -Example: to use the "nvim_get_current_line()" API function, call -"vim.api.nvim_get_current_line()": > - - print(tostring(vim.api.nvim_get_current_line())) - ------------------------------------------------------------------------------- -VIM.LOOP *lua-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)) - -Reference: http://docs.libuv.org -Examples: https://github.com/luvit/luv/tree/master/examples - - *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)) - -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: 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_connection) - 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_connection(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) - ------------------------------------------------------------------------------- -VIM *lua-util* - -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.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 indicies. If {index} is not - supplied, the length of the string is used. All indicies are zero-based. - Returns two values: the UTF-32 and UTF-16 indicies 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.schedule({callback}) *vim.schedule()* - Schedules {callback} to be invoked soon by the main event-loop. Useful - to avoid |textlock| or other temporary restrictions. - -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. +Moved to |lua.txt| ============================================================================== -Lua module: vim *lua-vim* - -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 - -paste({lines}, {phase}) *vim.paste()* - Paste handler, invoked by |nvim_paste()| when a conforming UI - (such as the |TUI|) pastes text into the editor. - - 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| - -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()| - - - - -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. - - Parameters: ~ - {orig} Table to copy - - Return: ~ - New table of copied keys and (nested) values. - -gsplit({s}, {sep}, {plain}) *vim.gsplit()* - Splits a string at each instance of a separator. - - Parameters: ~ - {s} String to split - {sep} Separator string or pattern - {plain} If `true` use `sep` literally (passed to - String.find) - - Return: ~ - Iterator over the split components - - See also: ~ - |vim.split()| - https://www.lua.org/pil/20.2.html - http://lua-users.org/wiki/StringLibraryTutorial - -split({s}, {sep}, {plain}) *vim.split()* - Splits a string at each instance of a separator. - - Examples: > - split(":aa::b:", ":") --> {'','aa','','bb',''} - split("axaby", "ab?") --> {'','x','y'} - split(x*yz*o, "*", true) --> {'x','yz','o'} -< - - Parameters: ~ - {s} String to split - {sep} Separator string or pattern - {plain} If `true` use `sep` literally (passed to - String.find) - - Return: ~ - List-like table of the split components. - - See also: ~ - |vim.gsplit()| - -tbl_contains({t}, {value}) *vim.tbl_contains()* - Checks if a list-like (vector) table contains `value` . - - Parameters: ~ - {t} Table to check - {value} Value to compare - - Return: ~ - true if `t` contains `value` - -tbl_extend({behavior}, {...}) *vim.tbl_extend()* - Merges two or more map-like tables. - - Parameters: ~ - {behavior} 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 - {...} Two or more map-like tables. - - See also: ~ - |extend()| - -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} List-like table - - Return: ~ - Flattened copy of the given list-like table. - -trim({s}) *vim.trim()* - Trim whitespace (Lua pattern "%s") from both sides of a - string. - - Parameters: ~ - {s} String to trim - - Return: ~ - String with whitespace removed from its beginning and end - - See also: ~ - https://www.lua.org/pil/20.2.html - -pesc({s}) *vim.pesc()* - Escapes magic chars in a Lua pattern string. - - Parameters: ~ - {s} String to escape - - Return: ~ - %-escaped pattern string - - See also: ~ - https://github.com/rxi/lume - - vim:tw=78:ts=8:ft=help:norl: + vim:tw=78:ts=8:noet:ft=help:norl: |