What triggers lazy loading?

[MartyMcFlyInTheSky]

I can't completely wrap my head around what "lazy loading" is in the contexts of neovim. From what I understand it triggers the plugin modules to be loaded into RAM. This would happen on the specified event triggers returned in dictionaries from our plugins.lua. On the other hand sometimes we require() a plugin.

From the Readme I got this:

When true, the plugin will only be loaded when needed. Lazy-loaded plugins are automatically loaded when their Lua modules are
required, or when one of the lazy-loading handlers triggers

Q1: Does this mean that without the lazyoption the plugins will never be lazy loaded on nvim startup even though an event is set (is it ignored)?

Now I have some keymappings defined, one for example triggers the command :Oilfrom oil.nvim. Am I right to assume that this call would shortcircuit or error if oil was not loaded at that point? Or Q2: does a keymapp invocation also trigger the lazy loading somehow?

Let's then say in one plugin file I require plugin Y as a dependency, while in another file I require Y directly, but I load lazily. Q3: When will Y now be loaded and what will be it's configuration? If I use require.setup({a=1}) and require("Y").setup({b=1}) respectively, will the two configs be merged? Is there an intermediary state where only a=1 is present and b=1 is not set yet?

I'm thankful for every hint I can get!

[WieeRd]

From what I understand it triggers the plugin modules to be loaded into RAM.

This is not true. In lazy.nvim, 'loading' a plugin means:

1. Adding the cloned plugin directory to the 'runtimepath'.
2. Running the scripts in the plugin's plugin/ directory.
3. If you specified opts or config key in the plugin spec, run require("plugin").setup(opts)

Does this mean that without the lazyoption the plugins will never be lazy loaded on nvim startup even though an event is set (is it ignored)?

No. Specifying one of the lazy loading triggers, event, ft, cmd and keys, implies lazy = true.

Am I right to assume that this call would shortcircuit or error if oil was not loaded at that point?

Yes and no. If you simply have:

{ "stevearc/oil.nvim", lazy = true },

And try to use :Oil command, it will fail, saying there is no such command.

But if you:

{ "stevearc/oil.nvim", cmd = "Oil" },

Now lazy.nvim will lazy-load oil.nvim right when you invoke :Oil. The plugin is loaded right when and only when it is needed. The same goes for the keybinds. If you specify the keymaps that require oil.nvim in the keys plugin spec, they will not fail even when oil.nvim is lazy loaded.

I'm not entirely sure what you mean by the last question. But lazy.nvim does load lazy plugins when they are require()'d. If you run require("plugin").setup(opts) twice, they will just run twice.
If you call require("oil").setup(opts) twice, it just means this function will be run twice with different options. Depending on the plugin, it'll break the plugin. Don't. If you want to specify different set of options in different parts of your plugin specs and want them to be merged, use opts key.

Neovim plugin ecosystem can be quite confusing for beginners. I recommend finish reading these docs:

• https://lazy.folke.io/spec
• :h 'runtimepath'
• :h lua-guide

[MartyMcFlyInTheSky]

Thanks a lot for your elaborate answer. I'll try to make heads and tails of the links you provided. But this already helped a bunch! :)