neovim/runtime/lua/vim/shared.lua

282 lines
8.2 KiB
Lua

-- Functions shared by Nvim and its test-suite.
--
-- The singular purpose of this module is to share code with the Nvim
-- test-suite. If, in the future, Nvim itself is used to run the test-suite
-- instead of "vanilla Lua", these functions could move to src/nvim/lua/vim.lua
local vim = {}
--- 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.
---
--@param orig Table to copy
--@returns New table of copied keys and (nested) values.
function vim.deepcopy(orig) end -- luacheck: no unused
vim.deepcopy = (function()
local function _id(v)
return v
end
local deepcopy_funcs = {
table = function(orig)
local copy = {}
for k, v in pairs(orig) do
copy[vim.deepcopy(k)] = vim.deepcopy(v)
end
return copy
end,
number = _id,
string = _id,
['nil'] = _id,
boolean = _id,
}
return function(orig)
return deepcopy_funcs[type(orig)](orig)
end
end)()
--- Splits a string at each instance of a separator.
---
--@see |vim.split()|
--@see https://www.lua.org/pil/20.2.html
--@see http://lua-users.org/wiki/StringLibraryTutorial
---
--@param s String to split
--@param sep Separator string or pattern
--@param plain If `true` use `sep` literally (passed to String.find)
--@returns Iterator over the split components
function vim.gsplit(s, sep, plain)
vim.validate{s={s,'s'},sep={sep,'s'},plain={plain,'b',true}}
local start = 1
local done = false
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 done then
return
end
if sep == '' then
if start == #s then
done = true
end
return _pass(start+1, start)
end
return _pass(s:find(sep, start, plain))
end
end
--- Splits a string at each instance of a separator.
---
--- Examples:
--- <pre>
--- split(":aa::b:", ":") --> {'','aa','','bb',''}
--- split("axaby", "ab?") --> {'','x','y'}
--- split(x*yz*o, "*", true) --> {'x','yz','o'}
--- </pre>
--
--@see |vim.gsplit()|
---
--@param s String to split
--@param sep Separator string or pattern
--@param plain If `true` use `sep` literally (passed to String.find)
--@returns List-like table of the split components.
function vim.split(s,sep,plain)
local t={} for c in vim.gsplit(s, sep, plain) do table.insert(t,c) end
return t
end
--- Checks if a list-like (vector) table contains `value`.
---
--@param t Table to check
--@param value Value to compare
--@returns true if `t` contains `value`
function vim.tbl_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
--- Merges two or more map-like tables.
---
--@see |extend()|
---
--@param 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
--@param ... Two or more map-like tables.
function vim.tbl_extend(behavior, ...)
if (behavior ~= 'error' and behavior ~= 'keep' and behavior ~= 'force') then
error('invalid "behavior": '..tostring(behavior))
end
local ret = {}
for i = 1, select('#', ...) do
local tbl = select(i, ...)
if tbl then
for k, v in pairs(tbl) do
if 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
--- Creates a copy of a list-like table such that any nested tables are
--- "unrolled" and appended to the result.
---
--@param t List-like table
--@returns Flattened copy of the given list-like table.
function vim.tbl_flatten(t)
-- From https://github.com/premake/premake-core/blob/master/src/base/table.lua
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
--- Trim whitespace (Lua pattern "%s") from both sides of a string.
---
--@see https://www.lua.org/pil/20.2.html
--@param s String to trim
--@returns 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 a Lua pattern string.
---
--@see https://github.com/rxi/lume
--@param s String to escape
--@returns %-escaped pattern string
function vim.pesc(s)
vim.validate{s={s,'s'}}
return s:gsub('[%(%)%.%%%+%-%*%?%[%]%^%$]', '%%%1')
end
--- Validates a parameter specification (types and values).
---
--- Usage example:
--- <pre>
--- function user.new(name, age, hobbies)
--- vim.validate{
--- name={name, 'string'},
--- age={age, 'number'},
--- hobbies={hobbies, 'table'},
--- }
--- ...
--- end
--- </pre>
---
--- Examples with explicit argument values (can be run directly):
--- <pre>
--- 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')
--- </pre>
---
--@param opt Map of parameter names to validations. 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 type name, one of: ("table", "t", "string",
--- "s", "number", "n", "boolean", "b", "function", "f", "nil",
--- "thread", "userdata")
--- - 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
--- - msg: (optional) error string if validation fails
function vim.validate(opt) end -- luacheck: no unused
vim.validate = (function()
local type_names = {
t='table', s='string', n='number', b='boolean', f='function', c='callable',
['table']='table', ['string']='string', ['number']='number',
['boolean']='boolean', ['function']='function', ['callable']='callable',
['nil']='nil', ['thread']='thread', ['userdata']='userdata',
}
local function _type_name(t)
local tname = type_names[t]
if tname == nil then
error(string.format('invalid type name: %s', tostring(t)))
end
return tname
end
local function _is_type(val, t)
return t == 'callable' and vim.is_callable(val) or type(val) == t
end
return function(opt)
assert(type(opt) == 'table', string.format('opt: expected table, got %s', type(opt)))
for param_name, spec in pairs(opt) do
assert(type(spec) == 'table', string.format('%s: expected table, got %s', param_name, type(spec)))
local val = spec[1] -- Argument value.
local t = spec[2] -- Type name, or callable.
local optional = (true == spec[3])
if not vim.is_callable(t) then -- Check type name.
if (not optional or val ~= nil) and not _is_type(val, _type_name(t)) then
error(string.format("%s: expected %s, got %s", param_name, _type_name(t), type(val)))
end
elseif not t(val) then -- Check user-provided validation function.
error(string.format("%s: expected %s, got %s", param_name, (spec[3] or '?'), val))
end
end
return true
end
end)()
--- Returns true if object `f` can be called as a function.
---
--@param f Any object
--@return 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
return vim