How to use vim.loop interactively in Neovim?

Question

I want to read texts with Neovim scrolling them down automatically. The following code provides such functionality:

local M = {}

function M.down()
    local timer = vim.loop.new_timer()
    local stop = false
    local sleep = 5000
    timer:start(1000, sleep, vim.schedule_wrap(function()
      local scroll_down = vim.api.nvim_replace_termcodes('normal <C-E>', true, true, true)
      vim.cmd(scroll_down)

      if stop then
        timer:close()
      end
    end))
end

return M

How can I interact with vim.loop by changing stop and sleep variables, so the scrolling can be made faster/slower, or stopped?

Answer 1

Incorporating @B Layer's feedback I came up with the following code, that is able to stop scrolling, make it slower/faster without creating global variables.

local M = {sleep = 1000, timer = nil}

function M.down()
    print(M.sleep)
    M.timer = vim.loop.new_timer()
    M.timer:start(1000, M.sleep, vim.schedule_wrap(function()
      local down = vim.api.nvim_replace_termcodes('normal <C-E>', true, true, true)
      vim.cmd(down)
    end))
end

function M.down_stop()
  if M.timer ~= nil then
    M.timer:close()
    M.timer = nil
  end
end

function M.down_slower()
  M.down_change(2)
end

function M.down_faster()
  M.down_change(0.5)
end

function M.down_change(n)
  M.down_stop()
  M.sleep = M.sleep*n
  M.down()
end

return M