What's your thought about Lua plugin?

[SirZenith]

I added the ability to load Lua plugin at startup to lf on my fork. You can check it out here: https://github.com/SirZenith/lf/tree/lua.

Wherever a config file is found, the program will look for plugins directory under parent directory of that config. And each directory under plugins that contains init.lua will be treated as a plugin.

lf then load and run those init.lua before any config file gets sourced. My current implementation allows Lua plugins to create new commands, register new sorting methods and adds event hook (on-load, on-init ...), register file previewer in Lua.

Here goes a simple example.

Config directory structure:

.
├── lfrc
└── plugins
    └── user
        ├── char-order.txt
        ├── init.lua
        └── locale.lua

Content of `init.lua`

local lf = require "lf"

local EventType = lf.EventType
local locale_compare_str = require "user.locale".locale_compare_str


---@type lf.PluginRet
return {
    command = {
        ["select-nontagged"] = function()
            local nav = app:nav()
            nav:unselect()

            local dir = nav:curr_dir()
            dir:files_for_each(function(_, file)
                local path = file:path()
                if not nav:get_tag(path) then
                    nav:select(path)
                end
            end)
        end,
        ["glob-select-nontagged"] = function(pattern)
            pattern = pattern or "*"

            local nav = app:nav()
            nav:unselect()

            local dir = nav:curr_dir()
            dir:files_for_each(function(_, file)
                if not lf.glob_match(pattern, file:name()) then
                    return
                end

                local path = file:path()
                if not nav:get_tag(path) then
                    nav:select(path)
                end
            end)
        end,
    },
    event_hook = {
        [EventType.OnInit] = function()
            os.execute("notify-send 'Hello LF'")
        end,
    },
    sort_method = {
        ["filetype-and-locale"] = function(list)
            table.sort(list, function(f1, f2)
                local ext1 = f1:ext()
                local ext2 = f2:ext()
                if ext1 ~= ext2 then
                    return ext1 < ext2
                end

                local name1 = f1:name()
                local name2 = f2:name()
                if name1 ~= name2 then
                    return locale_compare_str(name1, name2)
                end

                return false
            end)

            return list
        end
    },
}

lfrc content:

set sortby filetype-and-locale

What makes me want to have Lua plugin support, is I have some really personal requirements for lf to be more happy to use. Requirements being so personal, that I think no body other than me will actually get their hands dirty implementing them, and unlikely to live on as a feature in this repository.

With plugin system, I can do more precise selection that being aware of file status in lf, and make locale-aware sort on file list without walking into cross platform issue and UI flickering.

And user can probably customize the appearance of file list UI in the future, as mentioned in another discussion post.

A known limitation of gopher-lua runtime that I use, is it can't load C libraries. But still, running Lua scripts alone can already do many things.

So what do you guys think? Would you want lf to have plugin support? Would you be willing to maintain such feature?

[CatsDeservePets]

Personally, I am a fan of Lua since moving to nvim.

@joelim-work already made a post about possible Lua integration. #2531

[SirZenith]

Now my branch implemented following features:

• Defining command and its completion method in Lua with string or Lua function
• Defining lf event listener with Lua function
• Defining key map in Lua with string or Lua function
• Adding previewer functions that can be activate for certain files
• Adding new sort method with Lua function
• Call lf command from Lua
• Call lf shell command from Lua
• Change option values in Lua
• Adding extra meta value to file

And

• A bunch of type binding
• Lua state pool for asynchronously execute Lua calls.