neovim/runtime/lua/vim/shared.lua
Lewis Russell 59cf827f99 refactor(lsp): move client code to a regular Lua class
Problem:
  The LSP client code is implemented as a complicated closure-class
  (class defined in a single function).

Solution:
  Move LSP client code to a more conventional Lua class and move to a
  separate file.
2024-02-07 19:48:37 +00:00

1008 lines
28 KiB
Lua

-- Functions shared by Nvim and its test-suite.
--
-- These are "pure" lua functions not depending of the state of the editor.
-- Thus they should always be available whenever nvim-related lua code is run,
-- regardless if it is code in the editor itself, or in worker threads/processes,
-- or the test suite. (Eventually the test suite will be run in a worker process,
-- so this wouldn't be a separate case to consider)
---@diagnostic disable-next-line: lowercase-global
vim = vim or {}
---@generic T
---@param orig T
---@param cache? table<any,any>
---@return T
local function deepcopy(orig, cache)
if orig == vim.NIL then
return vim.NIL
elseif type(orig) == 'userdata' or type(orig) == 'thread' then
error('Cannot deepcopy object of type ' .. type(orig))
elseif type(orig) ~= 'table' then
return orig
end
--- @cast orig table<any,any>
if cache and cache[orig] then
return cache[orig]
end
local copy = {} --- @type table<any,any>
if cache then
cache[orig] = copy
end
for k, v in pairs(orig) do
copy[deepcopy(k, cache)] = deepcopy(v, cache)
end
return setmetatable(copy, getmetatable(orig))
end
--- 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.
---
--- Note: `noref=true` is much more performant on tables with unique table
--- fields, while `noref=false` is more performant on tables that reuse table
--- fields.
---
---@generic T: table
---@param orig T Table to copy
---@param noref? boolean
--- When `false` (default) a contained table is only copied once and all
--- references point to this single copy. When `true` every occurrence of a
--- table results in a new copy. This also means that a cyclic reference can
--- cause `deepcopy()` to fail.
---@return T Table of copied keys and (nested) values.
function vim.deepcopy(orig, noref)
return deepcopy(orig, not noref and {} or nil)
end
--- Gets an |iterator| that splits a string at each instance of a separator, in "lazy" fashion
--- (as opposed to |vim.split()| which is "eager").
---
--- Example:
---
--- ```lua
--- for s in vim.gsplit(':aa::b:', ':', {plain=true}) do
--- print(s)
--- end
--- ```
---
--- If you want to also inspect the separator itself (instead of discarding it), use
--- |string.gmatch()|. Example:
---
--- ```lua
--- for word, num in ('foo111bar222'):gmatch('([^0-9]*)(%d*)') do
--- print(('word: %s num: %s'):format(word, num))
--- end
--- ```
---
--- @see |string.gmatch()|
--- @see |vim.split()|
--- @see |lua-patterns|
--- @see https://www.lua.org/pil/20.2.html
--- @see http://lua-users.org/wiki/StringLibraryTutorial
---
--- @param s string String to split
--- @param sep string Separator or pattern
--- @param opts (table|nil) Keyword arguments |kwargs|:
--- - plain: (boolean) Use `sep` literally (as in string.find).
--- - trimempty: (boolean) Discard empty segments at start and end of the sequence.
---@return fun():string|nil (function) Iterator over the split components
function vim.gsplit(s, sep, opts)
local plain
local trimempty = false
if type(opts) == 'boolean' then
plain = opts -- For backwards compatibility.
else
vim.validate({ s = { s, 's' }, sep = { sep, 's' }, opts = { opts, 't', true } })
opts = opts or {}
plain, trimempty = opts.plain, opts.trimempty
end
local start = 1
local done = false
-- For `trimempty`: queue of collected segments, to be emitted at next pass.
local segs = {}
local empty_start = true -- Only empty segments seen so far.
local function _pass(i, j, ...)
if i then
assert(j + 1 > start, 'Infinite loop detected')
local seg = s:sub(start, i - 1)
start = j + 1
return seg, ...
else
done = true
return s:sub(start)
end
end
return function()
if trimempty and #segs > 0 then
-- trimempty: Pop the collected segments.
return table.remove(segs)
elseif done or (s == '' and sep == '') then
return nil
elseif sep == '' then
if start == #s then
done = true
end
return _pass(start + 1, start)
end
local seg = _pass(s:find(sep, start, plain))
-- Trim empty segments from start/end.
if trimempty and seg ~= '' then
empty_start = false
elseif trimempty and seg == '' then
while not done and seg == '' do
table.insert(segs, 1, '')
seg = _pass(s:find(sep, start, plain))
end
if done and seg == '' then
return nil
elseif empty_start then
empty_start = false
segs = {}
return seg
end
if seg ~= '' then
table.insert(segs, 1, seg)
end
return table.remove(segs)
end
return seg
end
end
--- Splits a string at each instance of a separator and returns the result as a table (unlike
--- |vim.gsplit()|).
---
--- Examples:
---
--- ```lua
--- 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'}
--- ```
---
---@see |vim.gsplit()|
---@see |string.gmatch()|
---
---@param s string String to split
---@param sep string Separator or pattern
---@param opts (table|nil) Keyword arguments |kwargs| accepted by |vim.gsplit()|
---@return string[] List of split components
function vim.split(s, sep, opts)
local t = {}
for c in vim.gsplit(s, sep, opts) do
table.insert(t, c)
end
return t
end
--- Return a list of all keys used in a table.
--- However, the order of the return table of keys is not guaranteed.
---
---@see From https://github.com/premake/premake-core/blob/master/src/base/table.lua
---
---@generic T: table
---@param t table<T, any> (table) Table
---@return T[] (list) List of keys
function vim.tbl_keys(t)
assert(type(t) == 'table', string.format('Expected table, got %s', type(t)))
local keys = {}
for k, _ in pairs(t) do
table.insert(keys, k)
end
return keys
end
--- Return a list of all values used in a table.
--- However, the order of the return table of values is not guaranteed.
---
---@generic T
---@param t table<any, T> (table) Table
---@return T[] (list) List of values
function vim.tbl_values(t)
assert(type(t) == 'table', string.format('Expected table, got %s', type(t)))
local values = {}
for _, v in pairs(t) do
table.insert(values, v)
end
return values
end
--- Apply a function to all values of a table.
---
---@generic T
---@param func fun(value: T): any (function) Function
---@param t table<any, T> (table) Table
---@return table Table of transformed values
function vim.tbl_map(func, t)
vim.validate({ func = { func, 'c' }, t = { t, 't' } })
local rettab = {}
for k, v in pairs(t) do
rettab[k] = func(v)
end
return rettab
end
--- Filter a table using a predicate function
---
---@generic T
---@param func fun(value: T): boolean (function) Function
---@param t table<any, T> (table) Table
---@return T[] (table) Table of filtered values
function vim.tbl_filter(func, t)
vim.validate({ func = { func, 'c' }, t = { t, 't' } })
local rettab = {}
for _, entry in pairs(t) do
if func(entry) then
table.insert(rettab, entry)
end
end
return rettab
end
--- Checks if a table contains a given value, specified either directly or via
--- a predicate that is checked for each value.
---
--- Example:
---
--- ```lua
--- vim.tbl_contains({ 'a', { 'b', 'c' } }, function(v)
--- return vim.deep_equal(v, { 'b', 'c' })
--- end, { predicate = true })
--- -- true
--- ```
---
---@see |vim.list_contains()| for checking values in list-like tables
---
---@param t table Table to check
---@param value any Value to compare or predicate function reference
---@param opts (table|nil) Keyword arguments |kwargs|:
--- - predicate: (boolean) `value` is a function reference to be checked (default false)
---@return boolean `true` if `t` contains `value`
function vim.tbl_contains(t, value, opts)
vim.validate({ t = { t, 't' }, opts = { opts, 't', true } })
local pred
if opts and opts.predicate then
vim.validate({ value = { value, 'c' } })
pred = value
else
pred = function(v)
return v == value
end
end
for _, v in pairs(t) do
if pred(v) then
return true
end
end
return false
end
--- Checks if a list-like table (integer keys without gaps) contains `value`.
---
---@see |vim.tbl_contains()| for checking values in general tables
---
---@param t table Table to check (must be list-like, not validated)
---@param value any Value to compare
---@return boolean `true` if `t` contains `value`
function vim.list_contains(t, value)
vim.validate({ t = { t, 't' } })
for _, v in ipairs(t) do
if v == value then
return true
end
end
return false
end
--- Checks if a table is empty.
---
---@see https://github.com/premake/premake-core/blob/master/src/base/table.lua
---
---@param t table Table to check
---@return boolean `true` if `t` is empty
function vim.tbl_isempty(t)
assert(type(t) == 'table', string.format('Expected table, got %s', type(t)))
return next(t) == nil
end
--- We only merge empty tables or tables that are not an array (indexed by integers)
local function can_merge(v)
return type(v) == 'table' and (vim.tbl_isempty(v) or not vim.tbl_isarray(v))
end
local function tbl_extend(behavior, deep_extend, ...)
if behavior ~= 'error' and behavior ~= 'keep' and behavior ~= 'force' then
error('invalid "behavior": ' .. tostring(behavior))
end
if select('#', ...) < 2 then
error(
'wrong number of arguments (given '
.. tostring(1 + select('#', ...))
.. ', expected at least 3)'
)
end
local ret = {}
if vim._empty_dict_mt ~= nil and getmetatable(select(1, ...)) == vim._empty_dict_mt then
ret = vim.empty_dict()
end
for i = 1, select('#', ...) do
local tbl = select(i, ...)
vim.validate({ ['after the second argument'] = { tbl, 't' } })
if tbl then
for k, v in pairs(tbl) do
if deep_extend and can_merge(v) and can_merge(ret[k]) then
ret[k] = tbl_extend(behavior, true, ret[k], v)
elseif behavior ~= 'force' and ret[k] ~= nil then
if behavior == 'error' then
error('key found in more than one map: ' .. k)
end -- Else behavior is "keep".
else
ret[k] = v
end
end
end
end
return ret
end
--- Merges two or more tables.
---
---@see |extend()|
---
---@param 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
---@param ... table Two or more tables
---@return table Merged table
function vim.tbl_extend(behavior, ...)
return tbl_extend(behavior, false, ...)
end
--- Merges recursively two or more tables.
---
---@see |vim.tbl_extend()|
---
---@generic T1: table
---@generic T2: table
---@param behavior "error"|"keep"|"force" (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
---@param ... T2 Two or more tables
---@return T1|T2 (table) Merged table
function vim.tbl_deep_extend(behavior, ...)
return tbl_extend(behavior, true, ...)
end
--- 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.
---@param a any First value
---@param b any Second value
---@return boolean `true` if values are equals, else `false`
function vim.deep_equal(a, b)
if a == b then
return true
end
if type(a) ~= type(b) then
return false
end
if type(a) == 'table' then
for k, v in pairs(a) do
if not vim.deep_equal(v, b[k]) then
return false
end
end
for k, _ in pairs(b) do
if a[k] == nil then
return false
end
end
return true
end
return false
end
--- 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.
---@param o table Table to add the reverse to
---@return table o
function vim.tbl_add_reverse_lookup(o)
local keys = vim.tbl_keys(o)
for _, k in ipairs(keys) do
local v = o[k]
if o[v] then
error(
string.format(
'The reverse lookup found an existing value for %q while processing key %q',
tostring(v),
tostring(k)
)
)
end
o[v] = k
end
return o
end
--- Index into a table (first argument) via string keys passed as subsequent arguments.
--- Return `nil` if the key does not exist.
---
--- Examples:
---
--- ```lua
--- vim.tbl_get({ key = { nested_key = true }}, 'key', 'nested_key') == true
--- vim.tbl_get({ key = {}}, 'key', 'nested_key') == nil
--- ```
---
---@param o table Table to index
---@param ... any Optional keys (0 or more, variadic) via which to index the table
---
---@return any Nested value indexed by key (if it exists), else nil
function vim.tbl_get(o, ...)
local keys = { ... }
if #keys == 0 then
return nil
end
for i, k in ipairs(keys) do
o = o[k]
if o == nil then
return nil
elseif type(o) ~= 'table' and next(keys, i) then
return nil
end
end
return o
end
--- Extends a list-like table with the values of another list-like table.
---
--- NOTE: This mutates dst!
---
---@see |vim.tbl_extend()|
---
---@generic T: table
---@param dst T List which will be modified and appended to
---@param src table List from which values will be inserted
---@param start (integer|nil) Start index on src. Defaults to 1
---@param finish (integer|nil) Final index on src. Defaults to `#src`
---@return T dst
function vim.list_extend(dst, src, start, finish)
vim.validate({
dst = { dst, 't' },
src = { src, 't' },
start = { start, 'n', true },
finish = { finish, 'n', true },
})
for i = start or 1, finish or #src do
table.insert(dst, src[i])
end
return dst
end
--- Creates a copy of a list-like table such that any nested tables are
--- "unrolled" and appended to the result.
---
---@see From https://github.com/premake/premake-core/blob/master/src/base/table.lua
---
---@param t table List-like table
---@return table Flattened copy of the given list-like table
function vim.tbl_flatten(t)
local result = {}
local function _tbl_flatten(_t)
local n = #_t
for i = 1, n do
local v = _t[i]
if type(v) == 'table' then
_tbl_flatten(v)
elseif v then
table.insert(result, v)
end
end
end
_tbl_flatten(t)
return result
end
--- Enumerates key-value pairs of a table, ordered by key.
---
---@see Based on https://github.com/premake/premake-core/blob/master/src/base/table.lua
---
---@param t table Dict-like table
---@return function # |for-in| iterator over sorted keys and their values
function vim.spairs(t)
assert(type(t) == 'table', string.format('Expected table, got %s', type(t)))
-- collect the keys
local keys = {}
for k in pairs(t) do
table.insert(keys, k)
end
table.sort(keys)
-- Return the iterator function.
local i = 0
return function()
i = i + 1
if keys[i] then
return keys[i], t[keys[i]]
end
end
end
--- Tests if `t` is an "array": a table indexed _only_ by integers (potentially non-contiguous).
---
--- If the indexes start from 1 and are contiguous then the array is also a list. |vim.tbl_islist()|
---
--- Empty table `{}` is 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|.
---
---@see https://github.com/openresty/luajit2#tableisarray
---
---@param t table
---@return boolean `true` if array-like table, else `false`.
function vim.tbl_isarray(t)
if type(t) ~= 'table' then
return false
end
local count = 0
for k, _ in pairs(t) do
-- Check if the number k is an integer
if type(k) == 'number' and k == math.floor(k) then
count = count + 1
else
return false
end
end
if count > 0 then
return true
else
-- TODO(bfredl): in the future, we will always be inside nvim
-- then this check can be deleted.
if vim._empty_dict_mt == nil then
return false
end
return getmetatable(t) ~= vim._empty_dict_mt
end
end
--- Tests if `t` is a "list": a table indexed _only_ by contiguous integers starting from 1 (what
--- |lua-length| calls a "regular array").
---
--- Empty table `{}` is a list, 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|.
---
---@see |vim.tbl_isarray()|
---
---@param t table
---@return boolean `true` if list-like table, else `false`.
function vim.tbl_islist(t)
if type(t) ~= 'table' then
return false
end
local num_elem = vim.tbl_count(t)
if num_elem == 0 then
return getmetatable(t) ~= vim._empty_dict_mt
else
for i = 1, num_elem do
if t[i] == nil then
return false
end
end
return true
end
end
--- Counts the number of non-nil values in table `t`.
---
--- ```lua
--- vim.tbl_count({ a=1, b=2 }) --> 2
--- vim.tbl_count({ 1, 2 }) --> 2
--- ```
---
---@see https://github.com/Tieske/Penlight/blob/master/lua/pl/tablex.lua
---@param t table Table
---@return integer Number of non-nil values in table
function vim.tbl_count(t)
vim.validate({ t = { t, 't' } })
local count = 0
for _ in pairs(t) do
count = count + 1
end
return count
end
--- Creates a copy of a table containing only elements from start to end (inclusive)
---
---@generic T
---@param list T[] (list) Table
---@param start integer|nil Start range of slice
---@param finish integer|nil End range of slice
---@return T[] (list) Copy of table sliced from start to finish (inclusive)
function vim.list_slice(list, start, finish)
local new_list = {}
for i = start or 1, finish or #list do
new_list[#new_list + 1] = list[i]
end
return new_list
end
--- Trim whitespace (Lua pattern "%s") from both sides of a string.
---
---@see |lua-patterns|
---@see https://www.lua.org/pil/20.2.html
---@param s string String to trim
---@return string String with whitespace removed from its beginning and end
function vim.trim(s)
vim.validate({ s = { s, 's' } })
return s:match('^%s*(.*%S)') or ''
end
--- Escapes magic chars in |lua-patterns|.
---
---@see https://github.com/rxi/lume
---@param s string String to escape
---@return string %-escaped pattern string
function vim.pesc(s)
vim.validate({ s = { s, 's' } })
return (s:gsub('[%(%)%.%%%+%-%*%?%[%]%^%$]', '%%%1'))
end
--- Tests if `s` starts with `prefix`.
---
---@param s string String
---@param prefix string Prefix to match
---@return boolean `true` if `prefix` is a prefix of `s`
function vim.startswith(s, prefix)
vim.validate({ s = { s, 's' }, prefix = { prefix, 's' } })
return s:sub(1, #prefix) == prefix
end
--- Tests if `s` ends with `suffix`.
---
---@param s string String
---@param suffix string Suffix to match
---@return boolean `true` if `suffix` is a suffix of `s`
function vim.endswith(s, suffix)
vim.validate({ s = { s, 's' }, suffix = { suffix, 's' } })
return #suffix == 0 or s:sub(-#suffix) == suffix
end
do
local type_names = {
['table'] = 'table',
t = 'table',
['string'] = 'string',
s = 'string',
['number'] = 'number',
n = 'number',
['boolean'] = 'boolean',
b = 'boolean',
['function'] = 'function',
f = 'function',
['callable'] = 'callable',
c = 'callable',
['nil'] = 'nil',
['thread'] = 'thread',
['userdata'] = 'userdata',
}
local function _is_type(val, t)
return type(val) == t or (t == 'callable' and vim.is_callable(val))
end
local function is_valid(opt)
if type(opt) ~= 'table' then
return false, string.format('opt: expected table, got %s', type(opt))
end
for param_name, spec in pairs(opt) do
if type(spec) ~= 'table' then
return false, string.format('opt[%s]: expected table, got %s', param_name, type(spec))
end
local val = spec[1] -- Argument value
local types = spec[2] -- Type name, or callable
local optional = (true == spec[3])
if type(types) == 'string' then
types = { types }
end
if vim.is_callable(types) then
-- Check user-provided validation function
local valid, optional_message = types(val)
if not valid then
local error_message =
string.format('%s: expected %s, got %s', param_name, (spec[3] or '?'), tostring(val))
if optional_message ~= nil then
error_message = error_message .. string.format('. Info: %s', optional_message)
end
return false, error_message
end
elseif type(types) == 'table' then
local success = false
for i, t in ipairs(types) do
local t_name = type_names[t]
if not t_name then
return false, string.format('invalid type name: %s', t)
end
types[i] = t_name
if (optional and val == nil) or _is_type(val, t_name) then
success = true
break
end
end
if not success then
return false,
string.format(
'%s: expected %s, got %s',
param_name,
table.concat(types, '|'),
type(val)
)
end
else
return false, string.format('invalid type name: %s', tostring(types))
end
end
return true, nil
end
--- Validates a parameter specification (types and values).
---
--- Usage example:
---
--- ```lua
--- 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):
---
--- ```lua
--- 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.
---
--- ```lua
--- 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')
---
--- ```
---
---@param 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
function vim.validate(opt)
local ok, err_msg = is_valid(opt)
if not ok then
error(err_msg, 2)
end
end
end
--- Returns true if object `f` can be called as a function.
---
---@param f any Any object
---@return boolean `true` if `f` is callable, else `false`
function vim.is_callable(f)
if type(f) == 'function' then
return true
end
local m = getmetatable(f)
if m == nil then
return false
end
return type(m.__call) == 'function'
end
--- Creates a table whose missing keys are provided by {createfn} (like Python's "defaultdict").
---
--- If {createfn} is `nil` it defaults to defaulttable() itself, so accessing nested keys creates
--- nested tables:
---
--- ```lua
--- local a = vim.defaulttable()
--- a.b.c = 1
--- ```
---
---@param createfn? fun(key:any):any Provides the value for a missing `key`.
---@return table # Empty table with `__index` metamethod.
function vim.defaulttable(createfn)
createfn = createfn or function(_)
return vim.defaulttable()
end
return setmetatable({}, {
__index = function(tbl, key)
rawset(tbl, key, createfn(key))
return rawget(tbl, key)
end,
})
end
do
---@class vim.Ringbuf<T>
---@field private _items table[]
---@field private _idx_read integer
---@field private _idx_write integer
---@field private _size integer
---@overload fun(self): table?
local Ringbuf = {}
--- Clear all items
function Ringbuf.clear(self)
self._items = {}
self._idx_read = 0
self._idx_write = 0
end
--- Adds an item, overriding the oldest item if the buffer is full.
---@generic T
---@param item T
function Ringbuf.push(self, item)
self._items[self._idx_write] = item
self._idx_write = (self._idx_write + 1) % self._size
if self._idx_write == self._idx_read then
self._idx_read = (self._idx_read + 1) % self._size
end
end
--- Removes and returns the first unread item
---@generic T
---@return T?
function Ringbuf.pop(self)
local idx_read = self._idx_read
if idx_read == self._idx_write then
return nil
end
local item = self._items[idx_read]
self._items[idx_read] = nil
self._idx_read = (idx_read + 1) % self._size
return item
end
--- Returns the first unread item without removing it
---@generic T
---@return T?
function Ringbuf.peek(self)
if self._idx_read == self._idx_write then
return nil
end
return self._items[self._idx_read]
end
--- Create a ring buffer limited to a maximal number of items.
--- Once the buffer is full, adding a new entry overrides the oldest entry.
---
--- ```lua
--- 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
--- ```
---
--- Returns a Ringbuf instance with the following methods:
---
--- - |Ringbuf:push()|
--- - |Ringbuf:pop()|
--- - |Ringbuf:peek()|
--- - |Ringbuf:clear()|
---
---@param size integer
---@return vim.Ringbuf ringbuf (table)
function vim.ringbuf(size)
local ringbuf = {
_items = {},
_size = size + 1,
_idx_read = 0,
_idx_write = 0,
}
return setmetatable(ringbuf, {
__index = Ringbuf,
__call = function(self)
return self:pop()
end,
})
end
end
--- @private
--- @generic T
--- @param root string
--- @param mod T
--- @return T
function vim._defer_require(root, mod)
return setmetatable({}, {
---@param t table<string, any>
---@param k string
__index = function(t, k)
if not mod[k] then
return
end
local name = string.format('%s.%s', root, k)
t[k] = require(name)
return t[k]
end,
})
end
return vim