How do I switch modes inside a user-defined lua function?

Question

I want to write a command to do the following:

1. Make a visual selection.
2. Call a command on the visual selection.

By way of example, I'd like to call vat to visually select around the current tag, and then use Limelight to highlight it.

Attempt #1:

vim.api.nvim_create_user_command('HighlightTagBlock',
    function()
        vim.cmd.normal("vat")
        vim.cmd("'<,'>Limelight")
    end,
    { nargs = 0 }
)

Attempt #2:

vim.api.nvim_create_user_command('HighlightTagBlock',
    function()
        vim.cmd.normal("vat")
        vim.cmd.visual("Limelight")
    end,
    { nargs = 0 }
)

Neither of these works as expected. What's the right way to do this?

Answer 1

I don't know neovim api, but <Plug>(Limelight) defined as visual mapping in Limelight might work:

vim.api.nvim_create_user_command('HighlightTagBlock',
    function()
        vim.cmd.normal("vat")
        vim.cmd.visual("<Plug>(Limelight)")
    end,
    { nargs = 0 }
)

Answer 2

I would do:

vim.api.nvim_create_user_command('HighlightTagBlock',
  [[
    execute 'normal vat'
    '<,'>Limelight
  ]],
  { nargs = 0 }
)

I have protected the normal call with execute since I otherwise the rest of the string is considered as an argument of the normal code.