Performance: should local utility functions reside in config = function() block?

[adrian5]

I have a few plugin configs that are fairly large (e.g. LSP, cmp). For clarity I refactored some of the code into helper functions. However, this doesn't help readability as much if they're defined/nested inside the lazy config function:

-- init.lua
require("lazy").setup("plugins", { … })

-- lua/plugins/some-plugin.lua
{
  …
  config = function()
    local verify = function(data) … end

    if verify(foo) then … end
  end
}

Is is costly if functions are defined outside of config but called inside it? I assume they aren't cached and lazy loaded the way a nested function is? Or is compilation cost negligible compared to execution anyway?

-- lua/plugins/some-plugin.lua
local get_items = function() … end
local verify = function(data) … end

return {
  "user/some-plugin.nvim",
  event = { "BufNewFile", "BufReadPost" }, -- Lazy
  config = function()
    for _, e in ipairs(get_items()) do … end
    if verify(foo) then … end
  end
}

[folke]

You can structure your config any way you like. Performance will be the same. You can also require external files in your config if needed. All files will be cached.

[adrian5]

Thank you, that's great to hear!

[LuluFischettiKY0]

If you define your functions outside of config, you could potentially improve readability and organization of your code. And if you're worried about performance, you could always test it out and see if there's any noticeable difference in execution time.

[adrian5]

Indeed. When I moved the function definitions back out, I didn't see a noticeable difference in the lazy.nvim profiler.