something wrong with luaeval()

[wsdjeg]

Problem

when use luaeval() to get the lua value, can not change the value.

Steps to reproduce

create two files:

1. autoload/testl.vim

function! testl#test() abort
  return luaeval('require("testluaeval").test()')
endfunction

2. lua/testluaeval.lua

--!/usr/bin/lua

local M = {}


function M.test() -- {{{
  local a = {}
  a.t = true
  function a.change_t() -- {{{
    a.t = false
  end
  return a
  -- }}}
end
-- }}}


return M

3. run following command:

let wsd = testl#test()
call wsd.change_t()
echo wsd.t

you will see v:true, but it should be v:false

4. it works well in lua:

lua wsd = require('testluaeval').test()
lua wsd.change_t()
lua print(wsd.t)

then it works well, and you will see false printed.

Expected behavior

in the reproduce step 3, echo wsd.t should be v:false.

Neovim version (nvim -v)

NVIM v0.7.0

Vim (not Nvim) behaves the same?

no

Operating system/version

win 11

Terminal name/version

neovim-qt

$TERM environment variable

empty

Installation

release page

[bfredl]

We don't have bindeval for tables. related: #1898 .

A workaround for your usecase might be to return both setter and a getter functions (closures are bound).

[bfredl]

are you sure? it works for me. check :messages in case the printed message got lost.

[wsdjeg]

@bfredl thanks, I fixed it in my plugin. as a workaroud for this:

change the lua code in step2 to:

local M = {}


function M.test() -- {{{
  local a = {}
  a.t = true
  function a.change_t() -- {{{
    a.t = false
  end
  function a.get_t() -- {{{
    return a.t
  end
  -- }}}
  return a
  -- }}}
end
-- }}}


return M

and in step 3:

let wsd = testl#test()
call wsd.change_t()
echo wsd.get_t()  " use get_t() function instead of value.