config = function() VS. opt = {} VS. opt = function()

[vynguyen205]

Hi! I am unsure when to use which? I do not know the difference even after reading the doc. I am very new to this. I haven't been able to find a good answer anywhere so hopefully you guys would be able to answer. Thank you so much!!

[dpetka2001]

If you're using your own custom config it doesn't matter which one you will use. If you use some distro, then you should always use opts and avoid config (unless you know explicitly what you're doing and you're certain you won't break things, but since you're new and don't know the difference you should definitely avoid it). The reason being that different instances of opts will get merged together, but the same thing will not happen when you use config. The latest config defined will overwrite the previous ones.

opts is essentially the table of configuration that each plugin gets and that is passed to the default config function, which by default does require("main_lua_module).setup(opts). If you define your own config function, then you also have to call require("main_lua_module").setup(opts) yourself. The main_lua_module is the top-level module in each plugin's file structure and usually that's also where the setup function is defined, but not all plugins follow that convention because it's just a convention and not a rule after all.

See also #2096 where I gave an example of what happens with plugin nvim-treesitter. Notice how the behavior is different between the plugin's main and master branch, because the master branch was the old branch and then the main branch was a complete rewrite from scratch and also changed quite a lot of the file structure of the plugin.

[vynguyen205]

Thank you so much! That's very clear!