Translated "https://gist.github.com/VictorTaelin/482d1de7a67c448253fd1cd2a54adf45" script to lua for Neovim

holefill.lua

" Calls GPT-4 to fill holes in the current file,
" omitting collapsed folds to save prompt space

local M = {}

local function save_visible_lines(dest)
  local visible_lines = {}
  local lnum = 1
  while lnum <= vim.fn.line('$') do
    if vim.fn.foldclosed(lnum) == -1 then
      table.insert(visible_lines, vim.fn.getline(lnum))
      lnum = lnum + 1
    else
      table.insert(visible_lines, vim.fn.getline(vim.fn.foldclosed(lnum)))
      table.insert(visible_lines, "...")
      table.insert(visible_lines, vim.fn.getline(vim.fn.foldclosedend(lnum)))
      lnum = vim.fn.foldclosedend(lnum) + 1
    end
  end
  vim.fn.writefile(visible_lines, dest)
end

function M.execute()
  local tmp_file = ''
  local holefill_exists = vim.fn.executable('holefill') > 0

  if not holefill_exists then
    print('Error: holefill executable not found. Please install it.')
    return
  end

  if (vim.fn.bufname('%') == '') then
    tmp_file = vim.fn.tempname()
    vim.cmd('w ' .. tmp_file)
  else
    vim.cmd('w')
    tmp_file = vim.fn.expand('%:p')
  end

  save_visible_lines('.fill.tmp')

  vim.fn.system('NODE_NO_WARNINGS=1 holefill ' .. tmp_file .. ' .fill.tmp')
  vim.fn.system('del .fill.tmp')

  vim.cmd('edit!')
end

return M