[feature request] Implementing '...' for Variable Declaration within Scope using Anonymous Functions

Hi,
In the Lua language, the ellipsis ... can only be used in the last function argument.

local function a(...)
    print(...)
end

It is not possible to declare it in the scope (e.g., as local ... = 1, 2).

local ok, ... = true, true -- syntax error! ('<name>' expected near '...')

My suggestion is to implement the use of ... to declare it in the scope, using anonymous functions for that purpose. During parsing, if there is ... in the variable declaration, Yuescript can wrap that scope inside a function and call it with the values. This way, ... will be defined within the same scope.

list = {1, 2, 3, 4, 5}
fn = (ok) ->
  ok, table.unpack list
ok, ... = fn true
print ok, ...
ok, ...

compiles to:

local list = {
  1, 
  2,
  3,
  4,
  5
}
local fn
fn = function(ok)
  return ok, table.unpack(list)
end
return (function(ok, ...)
    print(ok, ...) -- "ok" and "..." is available here without errors!
    return ok, ...
end)(fn(true))

local function fn_many_args()
    return 10, nil, 20, nil, 30
end

local args = {fn_many_args()}
print(#args) --> 1

local _ = (function(...)
    print(select("#", ...)) --> 5
    print(...) --> 10, nil, 20, nil, 30
end)(fn_many_args())


-- I can pass the function to select:
print(select("#", fn_many_args())) --> 5
-- But, How can I get the items? I will need call the function twice!
print(select(1, fn_many_args())) --> 10, nil, 20, nil, 30
-- First to get length, and second to catch the items

Regards

No files or tests are named. Start by locating the parser and compilation tests for variable declarations and anonymous functions, then trace how Lua varargs are represented. Done means scoped ... declarations compile and preserve multiple returns, including nil values, without breaking existing scope behavior.