Lua

简介 lua-intro

:lua vim.print(package.loaded)

nvim -l foo.lua [args...]

if jit then
  -- code for luajit
else
  -- code for plain lua 5.1
end

-- Start a profiling session:
require('jit.p').start('ri1', '/tmp/profile')
-- Perform arbitrary tasks (use plugins, scripts, etc.) ...
-- Stop the session. Profile is written to /tmp/profile.
require('jit.p').stop()

:lua vim.cmd.edit(package.searchpath('jit.p', package.path))

Lua 概念和习语 lua-concepts

---@return any|nil    # result on success, nil on failure.
---@return nil|string # nil on success, error message on failure.

local value = assert(fn())

local foo = function(a, b)
    print("A: ", a)
    print("B: ", b)
end

foo(1, 2)
-- ==== Result ====
-- A: 1
-- B: 2

foo(1)
-- ==== Result ====
-- A: 1
-- B: nil

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" }

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

导入 Lua 模块 lua-module-load

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

/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

命令 lua-commands

:lua vim.api.nvim_command('echo "Hello, Nvim!"')

:lua print(_VERSION)

:lua =jit.version

print(string.format(
    'unix time: %s', os.time()))

function! CurrentLineInfo()
lua << EOF
local linenr = vim.api.nvim_win_get_cursor(0)[1]
local curline = vim.api.nvim_buf_get_lines(0, linenr - 1, linenr, false)[1]
print(string.format('Line [%d] has %d bytes', linenr, #curline))
EOF
endfunction

: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 script.lua
:luafile %

luaeval() lua-eval

local chunkheader = "local _A = select(1, ...) return "
function luaeval (expstr, arg)
    local chunk = assert(loadstring(chunkheader .. expstr, "luaeval"))
    return chunk(arg) -- return typval
end

:echo luaeval('_A[1] + _A[2]', [40, 2])
" 42
:echo luaeval('string.match(_A, "[a-z]+")', 'XYXfoo123')
" foo

: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)

Vimscript v:lua 接口 v:lua-call

call v:lua.func(arg1, arg2)

return func(...)

call v:lua.somemod.func(args)

return somemod.func(...)

call v:lua.require'mypack'.func(arg1, arg2)
call v:lua.require'mypack.submod'.func(arg1, arg2)

:eval arg1->v:lua.somemod.func(arg2)

function mymod.omnifunc(findstart, base)
  if findstart == 1 then
    return 0
  else
    return {'stuff', 'steam', 'strange things'}
  end
end
vim.bo[buf].omnifunc = 'v:lua.mymod.omnifunc'

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 标准模块 lua-stdlib

:lua vim.print(vim)

{
  _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>,
  ...
}

:help vim.deepcopy()

VIM.UV lua-loop vim.uv

local timer = vim.uv.new_timer()
timer:start(1000, 0, function()
  vim.api.nvim_command('echomsg "test"')
end)

local timer = vim.uv.new_timer()
timer:start(1000, 0, vim.schedule_wrap(function()
  vim.api.nvim_command('echomsg "test"')
end))

-- Create a timer handle (implementation detail: uv_timer_t).
local timer = vim.uv.new_timer()
local i = 0
-- Waits 1000ms, then repeats every 750ms until timer:close().
timer:start(1000, 750, function()
  print('timer invoked! i='..tostring(i))
  if i > 4 then
    timer:close()  -- Always close handles to avoid leaks.
  end
  i = i + 1
end)
print('sleeping');

local w = vim.uv.new_fs_event()
local function on_change(err, fname, status)
  -- Do work...
  vim.api.nvim_command('checktime')
  -- Debounce: stop/start.
  w:stop()
  watch_file(fname)
end
function watch_file(fname)
  local fullpath = vim.api.nvim_call_function(
    'fnamemodify', {fname, ':p'})
  w:start(fullpath, {}, vim.schedule_wrap(function(...)
    on_change(...) end))
end
vim.api.nvim_command(
  "command! -nargs=1 Watch call luaeval('watch_file(_A)', expand('<args>'))")

sysctl fs.inotify.max_user_watches=494462

local function create_server(host, port, on_connect)
  local server = vim.uv.new_tcp()
  server:bind(host, port)
  server:listen(128, function(err)
    assert(not err, err)  -- Check for errors.
    local sock = vim.uv.new_tcp()
    server:accept(sock)  -- Accept client connection.
    on_connect(sock)  -- Start reading messages.
  end)
  return server
end
local server = create_server('0.0.0.0', 0, function(sock)
  sock:read_start(function(err, chunk)
    assert(not err, err)  -- Check for errors.
    if chunk then
      sock:write(chunk)  -- Echo received messages to the channel.
    else  -- EOF (stream closed).
      sock:close()  -- Always close handles to avoid leaks.
    end
  end)
end)
print('TCP echo-server listening on port: '..server:getsockname().port)

VIM.HL vim.hl

autocmd TextYankPost * silent! lua vim.hl.on_yank {higroup='Visual', timeout=300}

VIM.DIFF vim.diff

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}
-- }

VIM.MPACK vim.mpack

VIM.JSON vim.json

vim.print(vim.json.decode('{"bar":[],"foo":{},"zub":null}'))
-- { bar = {}, foo = vim.empty_dict(), zub = vim.NIL }

VIM.BASE64 vim.base64

VIM.SPELL vim.spell

vim.spell.check("the quik brown fox")
-- =>
-- {
--     {'quik', 'bad', 5}
-- }

VIM vim.builtin

print(tostring(vim.api.nvim_get_current_line()))

{
  [vim.type_idx] = vim.types.float,
  [vim.val_idx] = 1.0,
}

-- The character 'æ' is stored as the bytes '\xc3\xa6' (using UTF-8)
-- Returns 0 because the index is pointing at the last byte of a character
vim.str_utf_end('æ', 2)
-- Returns 1 because the index is pointing at the penultimate byte of a character
vim.str_utf_end('æ', 1)

-- The character 'æ' is stored as the bytes '\xc3\xa6' (using UTF-8)
-- Returns 0 because the index is pointing at the first byte of a character
vim.str_utf_start('æ', 1)
-- Returns -1 because the index is pointing at the second byte of a character
vim.str_utf_start('æ', 2)

ns = vim.api.nvim_create_namespace('my_fancy_pum')
vim.ui_attach(ns, {ext_popupmenu=true}, function(event, ...)
  if event == "popupmenu_show" then
    local items, selected, row, col, grid = ...
    print("display pum ", #items)
  elseif event == "popupmenu_select" then
    local selected = ...
    print("selected", selected)
  elseif event == "popupmenu_hide" then
    print("FIN")
  end
end)

---
-- 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

LUA-VIMSCRIPT 桥接 lua-vimscript

local list = { 1, 2, 3 }
vim.fn.remove(list, 0)
vim.print(list)  --> "{ 1, 2, 3 }"

vim.fn[func]({...})

vim.fn['some#function']({...})

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.my_dict.field1 = 'value'  -- Does not work
local my_dict = vim.g.my_dict   --
my_dict.field1 = 'value'        -- Instead do
vim.g.my_dict = my_dict         --

set wildignore=*.o,*.a,__pycache__

vim.o.wildignore = '*.o,*.a,__pycache__'

vim.opt.wildignore = { '*.o', '*.a', '__pycache__' }

vim.opt.wildignore:append { "*.pyc", "node_modules" }

vim.opt.wildignore:prepend { "new_first_value" }

vim.opt.wildignore:remove { "node_modules" }

set listchars=space:_,tab:>~

vim.o.listchars = 'space:_,tab:>~'

vim.opt.listchars = { space = '_', tab = '>~' }

echo wildignore

print(vim.o.wildignore)

vim.print(vim.opt.wildignore:get())

vim.opt.formatoptions:append('j')
vim.opt.formatoptions = vim.opt.formatoptions + 'j'

vim.cmd [[set wildignore=*.pyc,*.o]]
vim.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

vim.cmd [[set listchars=space:_,tab:>~]]
vim.print(vim.opt.listchars:get())
--  { space = "_", tab = ">~", }
for char, representation in pairs(vim.opt.listchars:get()) do
    print(char, "=>", representation)
end

vim.cmd [[set formatoptions=njtcroql]]
vim.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.wildignore:prepend('*.o')
vim.opt.wildignore = vim.opt.wildignore ^ '*.o'

vim.opt.wildignore:remove('*.pyc')
vim.opt.wildignore = vim.opt.wildignore - '*.pyc'

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.env.FOO = 'bar'
print(vim.env.TERM)

vim.go.cmdheight = 4
print(vim.go.columns)
print(vim.go.bar)     -- error: invalid key

vim.o.cmdheight = 4
print(vim.o.columns)
print(vim.o.foo)     -- error: invalid key

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
vim.wo[winid][0].spell = false -- like ':setlocal nospell'

Lua 模块：vim lua-vim

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')

local k = vim.keycode
vim.g.mapleader = k'<bs>'

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
    return overridden(lines, phase)
  end
end)(vim.paste)

local hl_normal = vim.print(vim.api.nvim_get_hl(0, { name = 'Normal' }))

function notify_readable(_err, readable)
  vim.notify("readable? " .. tostring(readable))
end
vim.uv.fs_access(vim.fn.stdpath("config"), "R", vim.schedule_wrap(notify_readable))

local on_exit = function(obj)
  print(obj.code)
  print(obj.signal)
  print(obj.stdout)
  print(obj.stderr)
end
-- Runs asynchronously:
vim.system({'echo', 'hello'}, { text = true }, on_exit)
-- Runs synchronously:
local obj = vim.system({'echo', 'hello'}, { text = true }):wait()
-- { code = 0, signal = 0, stdout = 'hello', stderr = '' }

Lua 模块：vim.inspector vim.inspector

local a = vim.defaulttable()
a.b.c = 1

for s in vim.gsplit(':aa::b:', ':', {plain=true}) do
  print(s)
end

for word, num in ('foo111bar222'):gmatch('([^0-9]*)(%d*)') do
  print(('word: %s num: %s'):format(word, num))
end

local ringbuf = vim.ringbuf(4)
ringbuf:push("a")
ringbuf:push("b")
ringbuf:push("c")
ringbuf:push("d")
ringbuf:push("e")    -- overrides "a"
print(ringbuf:pop()) -- returns "b"
print(ringbuf:pop()) -- returns "c"
-- Can be used as iterator. Pops remaining items:
for val in ringbuf do
  print(val)
end

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'}

vim.tbl_contains({ 'a', { 'b', 'c' } }, function(v)
  return vim.deep_equal(v, { 'b', 'c' })
end, { predicate = true })
-- true

vim.tbl_count({ a=1, b=2 })  --> 2
vim.tbl_count({ 1, 2 })      --> 2

vim.tbl_get({ key = { nested_key = true }}, 'key', 'nested_key') == true
vim.tbl_get({ key = {}}, 'key', 'nested_key') == nil

 function vim.startswith(s, prefix)
  vim.validate('s', s, 'string')
  vim.validate('prefix', prefix, 'string')
  ...
end

 function user.new(name, age, hobbies)
  vim.validate{
    name={name, 'string'},
    age={age, 'number'},
    hobbies={hobbies, 'table'},
  }
  ...
end

vim.validate('arg1', {'foo'}, 'table')
   --> NOP (success)
vim.validate('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')

vim.validate('arg1', {'foo'}, {'table', 'string'})
vim.validate('arg2', 'foo', {'table', 'string'})
-- NOP (success)
vim.validate('arg1', 1, {'string', 'table'})
-- error('arg1: expected string|table, got number')

Lua 模块：vim.loader vim.loader

Lua 模块：vim.uri vim.uri

Lua 模块：vim.ui vim.ui

vim.ui.input({ prompt = 'Enter value for shiftwidth: ' }, function(input)
    vim.o.shiftwidth = tonumber(input)
end)

-- Asynchronous.
vim.ui.open("https://neovim.cn/")
vim.ui.open("~/path/to/file")
-- Use the "osurl" command to handle the path or URL.
vim.ui.open("gh#neovim/neovim!29490", { cmd = { 'osurl' } })
-- Synchronous (wait until the process exits).
local cmd, err = vim.ui.open("$VIMRUNTIME")
if cmd then
  cmd:wait()
end

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)

Lua 模块：vim.filetype vim.filetype

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 } },
    -- A pattern containing an environment variable
    ['${XDG_CONFIG_HOME}/foo/git'] = 'git',
    ['.*README.(%a+)'] = function(path, bufnr, ext)
      if ext == 'md' then
        return 'markdown'
      elseif ext == 'rst' then
        return 'rst'
      end
    end,
  },
})

vim.filetype.add {
  pattern = {
    ['.*'] = {
      function(path, bufnr)
        local content = vim.api.nvim_buf_get_lines(bufnr, 0, 1, false)[1] or ''
        if vim.regex([[^#!.*\\<mine\\>]]):match_str(content) ~= nil then
          return 'mine'
        elseif vim.regex([[\\<drawing\\>]]):match_str(content) ~= nil then
          return 'drawing'
        end
      end,
      { priority = -math.huge },
    },
  },
}

vim.filetype.get_option('vim', 'commentstring')

-- 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'} })

Lua 模块: vim.keymap vim.keymap

vim.keymap.del('n', 'lhs')
vim.keymap.del({'n', 'i', 'v'}, '<leader>w', { buffer = 5 })

-- Map "x" to a Lua function:
vim.keymap.set('n', 'x', function() print("real lua function") end)
-- Map "<leader>x" to multiple modes for the current buffer:
vim.keymap.set({'n', 'v'}, '<leader>x', vim.lsp.buf.references, { buffer = true })
-- Map <Tab> to an expression (|:map-<expr>|):
vim.keymap.set('i', '<Tab>', function()
  return vim.fn.pumvisible() == 1 and "<C-n>" or "<Tab>"
end, { expr = true })
-- Map "[%%" to a <Plug> mapping:
vim.keymap.set('n', '[%%', '<Plug>(MatchitNormalMultiBackward)')

Lua 模块: vim.fs vim.fs

-- list all test directories under the runtime directory
local test_dirs = vim.fs.find(
  {'test', 'tst', 'testdir'},
  {limit = math.huge, type = 'directory', path = './runtime/'}
)
-- get all files ending with .cpp or .hpp inside lib/
local cpp_hpp = vim.fs.find(function(name, path)
  return name:match('.*%.[ch]pp$') and path:match('[/\\\\]lib$')
end, {limit = math.huge, type = 'file'})

[[C:\Users\jdoe]]                         => "C:/Users/jdoe"
"~/src/neovim"                            => "/home/jdoe/src/neovim"
"$XDG_CONFIG_HOME/nvim/init.vim"          => "/Users/jdoe/.config/nvim/init.vim"
"~/src/nvim/api/../tui/./tui.c"           => "/home/jdoe/src/nvim/tui/tui.c"
"./foo/bar"                               => "foo/bar"
"foo/../../../bar"                        => "../../bar"
"/home/jdoe/../../../bar"                 => "/bar"
"C:foo/../../baz"                         => "C:../baz"
"C:/foo/../../baz"                        => "C:/baz"
[[\\?\UNC\server\share\foo\..\..\..\bar]] => "//?/UNC/server/share/bar"

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

-- Find the root of a Python project, starting from file 'main.py'
vim.fs.root(vim.fs.joinpath(vim.env.PWD, 'main.py'), {'pyproject.toml', 'setup.py' })
-- Find the root of a git repository
vim.fs.root(0, '.git')
-- Find the parent directory containing any file with a .csproj extension
vim.fs.root(0, function(name, path)
  return name:match('%.csproj$') ~= nil
end)

Lua 模块: vim.glob vim.glob

VIM.LPEG vim.lpeg

local pattern = lpeg.R('az') ^ 1 * -1
assert(pattern:match('hello') == 6)
assert(lpeg.match(pattern, 'hello') == 6)
assert(pattern:match('1 hello') == nil)

local function split (s, sep)
  sep = lpeg.P(sep)
  local elem = lpeg.C((1 - sep) ^ 0)
  local p = elem * (sep * elem) ^ 0
  return lpeg.match(p, s)
end
local a, b, c = split('a,b,c', ',')
assert(a == 'a')
assert(b == 'b')
assert(c == 'c')

local number = lpeg.R('09') ^ 1 / tonumber
local list = number * (',' * number) ^ 0
local function add(acc, newvalue) return acc + newvalue end
local sum = lpeg.Cf(list, add)
assert(sum:match('10,30,43') == 83)

local I = lpeg.Cp()
local function anywhere(p) return lpeg.P({I * p * I + 1 * lpeg.V(1)}) end
local match_start, match_end = anywhere('world'):match('hello world!')
assert(match_start == 7)
assert(match_end == 12)

local function gsub (s, patt, repl)
  patt = lpeg.P(patt)
  patt = lpeg.Cs((patt / repl + 1) ^ 0)
  return lpeg.match(patt, s)
end
assert(gsub('Hello, xxx!', 'xxx', 'World') == 'Hello, World!')

lpeg.locale(lpeg)
local space = lpeg.space ^ 0
local name = lpeg.C(lpeg.alpha ^ 1) * space
local sep = lpeg.S(',;') * space
local pair = lpeg.Cg(name * '=' * space * name) * sep ^ -1
local list = lpeg.Cf(lpeg.Ct('') * pair ^ 0, rawset)
local t = list:match('a=b, c = hi; next = pi')
assert(t.a == 'b')
assert(t.c == 'hi')
assert(t.next == 'pi')
local locale = lpeg.locale()
assert(type(locale.digit) == 'userdata')

local pattern = lpeg.R('az') ^ 1 * -1
assert(pattern:match('hello') == 6)
assert(lpeg.match(pattern, 'hello') == 6)
assert(pattern:match('1 hello') == nil)

local pattern = lpeg.R('az') ^ 1 * -1
assert(pattern:match('hello') == 6)

local b = lpeg.P({'(' * ((1 - lpeg.S '()') + lpeg.V(1)) ^ 0 * ')'})
assert(b:match('((string))') == 11)
assert(b:match('(') == nil)

VIM.RE vim.re

VIM.REGEX vim.regex

Lua 模块：vim.secure vim.secure

Lua 模块：vim.version vim.version

local v = vim.version.parse(vim.fn.system({'tmux', '-V'}), {strict=false})
if vim.version.gt(v, {3, 2, 0}) then
  -- ...
end

版本范围规范 version-range

1.2.3             is 1.2.3
=1.2.3            is 1.2.3
>1.2.3            greater than 1.2.3
<1.2.3            before 1.2.3
>=1.2.3           at least 1.2.3
~1.2.3            is >=1.2.3 <1.3.0       "reasonably close to 1.2.3"
^1.2.3            is >=1.2.3 <2.0.0       "compatible with 1.2.3"
^0.2.3            is >=0.2.3 <0.3.0       (0.x.x is special)
^0.0.1            is =0.0.1               (0.0.x is special)
^1.2              is >=1.2.0 <2.0.0       (like ^1.2.0)
~1.2              is >=1.2.0 <1.3.0       (like ~1.2.0)
^1                is >=1.0.0 <2.0.0       "compatible with 1"
~1                same                    "reasonably close to 1"
1.x               same
1.*               same
1                 same
*                 any version
x                 same
1.2.3 - 2.3.4     is >=1.2.3 <=2.3.4
Partial right: missing pieces treated as x (2.3 => 2.3.x).
1.2.3 - 2.3       is >=1.2.3 <2.4.0
1.2.3 - 2         is >=1.2.3 <3.0.0
Partial left: missing pieces treated as 0 (1.2 => 1.2.0).
1.2 - 2.3.0       is 1.2.0 - 2.3.0

if vim.version.cmp({1,0,3}, {0,2,1}) == 0 then
  -- ...
end
local v1 = vim.version.parse('1.0.3-pre')
local v2 = vim.version.parse('0.2.1')
if vim.version.cmp(v1, v2) == 0 then
  -- ...
end

{ major = 1, minor = 0, patch = 1, prerelease = "rc1", build = "build.2" }

{
  from: Version
  to: Version
  has(v: string|Version)
}

local r = vim.version.range('1.0.0 - 2.0.0')
print(r:has('1.9.9'))       -- true
print(r:has('2.0.0'))       -- false
print(r:has(vim.version())) -- check against current Nvim version

local r = vim.version.range('1.0.0 - 2.0.0') -- >=1.0, <2.0
print(vim.version.ge({1,0,3}, r.from) and vim.version.lt({1,0,3}, r.to))

Lua 模块：vim.iter vim.iter

local it = vim.iter({ 1, 2, 3, 4, 5 })
it:map(function(v)
  return v * 3
end)
it:rev()
it:skip(2)
it:totable()
-- { 9, 6, 3 }
-- ipairs() is a function iterator which returns both the index (i) and the value (v)
vim.iter(ipairs({ 1, 2, 3, 4, 5 })):map(function(i, v)
  if i > 2 then return v end
end):totable()
-- { 3, 4, 5 }
local it = vim.iter(vim.gsplit('1,2,3,4,5', ','))
it:map(function(s) return tonumber(s) end)
for i, d in it:enumerate() do
  print(string.format("Column %d is %d", i, d))
end
-- Column 1 is 1
-- Column 2 is 2
-- Column 3 is 3
-- Column 4 is 4
-- Column 5 is 5
vim.iter({ a = 1, b = 2, c = 3, z = 26 }):any(function(k, v)
  return k == 'z'
end)
-- true
local rb = vim.ringbuf(3)
rb:push("a")
rb:push("b")
vim.iter(rb):totable()
-- { "a", "b" }

vim.iter(ipairs(t))

vim.iter(t):enumerate()

local it = vim.iter(vim.gsplit('abc', '')):enumerate()
it:next()
-- 1        'a'
it:next()
-- 2        'b'
it:next()
-- 3        'c'

local bufs = vim.iter(vim.api.nvim_list_bufs()):filter(vim.api.nvim_buf_is_loaded)

local it = vim.iter({ 3, 6, 9, 12 })
it:find(12)
-- 12
local it = vim.iter({ 3, 6, 9, 12 })
it:find(20)
-- nil
local it = vim.iter({ 3, 6, 9, 12 })
it:find(function(v) return v % 4 == 0 end)
-- 12

vim.iter({ 1, { 2 }, { { 3 } } }):flatten():totable()
-- { 1, 2, { 3 } }
vim.iter({1, { { a = 2 } }, { 3 } }):flatten():totable()
-- { 1, { a = 2 }, 3 }
vim.iter({ 1, { { a = 2 } }, { 3 } }):flatten(math.huge):totable()
-- error: attempt to flatten a dict-like table

-- Create a new table with only even values
vim.iter({ a = 1, b = 2, c = 3, d = 4 })
  :filter(function(k, v) return v % 2 == 0 end)
  :fold({}, function(acc, k, v)
    acc[k] = v
    return acc
  end) --> { b = 2, d = 4 }
-- Get the "maximum" item of an iterable.
vim.iter({ -99, -4, 3, 42, 0, 0, 7 })
  :fold({}, function(acc, v)
    acc.max = math.max(v, acc.max or v)
    return acc
  end) --> { max = 42 }

local it = vim.iter(vim.gsplit('abcdefg', ''))
it:last()
-- 'g'
local it = vim.iter({ 3, 6, 9, 12, 15 })
it:last()
-- 15

local it = vim.iter({ 1, 2, 3, 4 }):map(function(v)
  if v % 2 == 0 then
    return v * 3
  end
end)
it:totable()
-- { 6, 12 }

local it = vim.iter(string.gmatch('1 2 3', '%d+')):map(tonumber)
it:next()
-- 1
it:next()
-- 2
it:next()
-- 3

local it = vim.iter({ 3, 6, 9, 12 })
it:nth(2)
-- 6
it:nth(2)
-- 12
local it2 = vim.iter({ 3, 6, 9, 12 })
it2:nth(-2)
-- 9
it2:nth(-2)
-- 3

local it = vim.iter({ 3, 6, 9, 12 })
it:peek()
-- 3
it:peek()
-- 3
it:next()
-- 3

local it = vim.iter({1, 2, 3, 4})
it:pop()
-- 4
it:pop()
-- 3

local it = vim.iter({ 3, 6, 9, 12 }):rev()
it:totable()
-- { 12, 9, 6, 3 }

local it = vim.iter({ 1, 2, 3, 2, 1 }):enumerate()
it:rfind(1)
-- 5        1
it:rfind(1)
-- 1        1

local it = vim.iter({1, 2, 3, 4})
it:rpeek()
-- 4
it:rpeek()
-- 4
it:pop()
-- 4

local it = vim.iter({ 1, 2, 3, 4, 5 }):rskip(2)
it:next()
-- 1
it:pop()
-- 3

local it = vim.iter({ 3, 6, 9, 12 }):skip(2)
it:next()
-- 9

local it = vim.iter({ 1, 2, 3, 4 }):take(2)
it:next()
-- 1
it:next()
-- 2
it:next()
-- nil

vim.iter(string.gmatch('100 20 50', '%d+')):map(tonumber):totable()
-- { 100, 20, 50 }
vim.iter({ 1, 2, 3 }):map(function(v) return v, 2 * v end):totable()
-- { { 1, 2 }, { 2, 4 }, { 3, 6 } }
vim.iter({ a = 1, b = 2, c = 3 }):filter(function(k, v) return v % 2 ~= 0 end):totable()
-- { { 'a', 1 }, { 'c', 3 } }

Lua 模块：vim.snippet vim.snippet

vim.keymap.set({ 'i', 's' }, '<Tab>', function()
   if vim.snippet.active({ direction = 1 }) then
     return '<Cmd>lua vim.snippet.jump(1)<CR>'
   else
     return '<Tab>'
   end
 end, { expr = true })

vim.keymap.set({ 'i', 's' }, '<Tab>', function()
   if vim.snippet.active({ direction = 1 }) then
     return '<Cmd>lua vim.snippet.jump(1)<CR>'
   else
     return '<Tab>'
   end
 end, { expr = true })

Lua 模块：vim.text vim.text

Lua 模块：tohtml vim.tohtml