feat: Add toggle_pin and close_unpinned

Adds Ex commands `Hbac toggle_pin` and `Hbac close_unpinned` and their Lua counterparts, renaming `require("hbac)".close_unused()` to `close_unpinned`.

`toggle_pin` adds or removes the current buffer to/from the pinned buffers table. Pinned buffers won't be closed by the autoclose function after reaching the user-defined threshold. Instead, the oldest unpinned/unedited buffers will be closed instead.  Pinning buffers also makes it possible to keep more buffers open than the threshold without having to change hbac's options. Unpinning a buffer makes that buffer eligible for auto-close the next time a new buffer is opened.

Toggling the pin state with a command pins a buffer without having to edit it or enter insert mode to pin it implicitly. Moreover, the user is notified when a buffer is pinned/unpinned, giving the user explicit feedback on a buffer's pin state.

This is a squashed commit with major refactors made by @axkirillov

README.md

@@ -6,7 +6,7 @@ Automagically close the unedited buffers in your bufferlist when it becomes too
 # description
 You like using the buffer list, but you hate it when it has too many buffers, because you loose the overview for what files you are *actually* working on. Indeed, a lot of the times, when browsing code you want to look at some files, that you are not actively working on, like checking the definitions or going down the callstack when debugging. These files then pollute the bufferlist and make it harder to find ones you actually care about.
 Reddit user **xmsxms** [posted](https://www.reddit.com/r/neovim/comments/12c4ad8/closing_unused_buffers/?utm_source=share&utm_medium=web2x&context=3) a script that marks all once edited files in a session as important and provides a keybinding to close all the rest. In fact, I used some of his code in this plugin, and you can achieve the same effect as his script using hbac.
-The main feature of this plugin, however, is the automatic closing of buffers. If the number of buffers reaches a threschold (default is 10), the oldest unedited buffer will be closed once you open a new one.
+The main feature of this plugin, however, is the automatic closing of buffers. If the number of buffers reaches a threshold (default is 10), the oldest unedited buffer will be closed once you open a new one.
 
 # installation
 
@@ -37,4 +37,12 @@ Let hbac do its magick 😊
 
 or
 
-use `require("hbac").close_unused()` to close all unedited buffers
+- `:Hbac toggle_pin` - toggle a pin of the current buffer to prevent it from being auto-closed
+- `:Hbac close_unpinned` - close all unedited/unpinned buffers
+
+or, if you prefer to use lua:
+
+```lua
+require("hbac").toggle_pin()
+require("hbac").close_unpinned()
+```

lua/hbac/command.lua

@@ -0,0 +1,41 @@
+local state = require("hbac.state")
+
+local M = {
+	subcommands = {}
+}
+
+M.subcommands.close_unpinned = function()
+	local curbufnr = vim.api.nvim_get_current_buf()
+	local buflist = vim.api.nvim_list_bufs()
+	for _, bufnr in ipairs(buflist) do
+		if vim.bo[bufnr].buflisted and bufnr ~= curbufnr and not state.is_pinned(bufnr) then
+			vim.cmd('bd ' .. tostring(bufnr))
+		end
+	end
+	print("Hbac: Closed unpinned buffers")
+end
+
+
+M.subcommands.toggle_pin = function()
+	local bufnr = vim.api.nvim_get_current_buf()
+	print("Hbac: Buffer " .. bufnr .. " " .. state.toggle_pin(bufnr))
+end
+
+M.vim_cmd_name = "Hbac"
+
+M.vim_cmd_func = function(arg)
+	if M.subcommands[arg] then
+		M.subcommands[arg]()
+	else
+		print("Unknown Hbac command:", arg)
+	end
+end
+
+M.vim_cmd_opts = {
+	nargs = 1,
+	complete = function()
+		return { unpack(vim.tbl_keys(M.subcommands)) }
+	end,
+}
+
+return M

lua/hbac/init.lua

@@ -1,98 +1,8 @@
-local id = vim.api.nvim_create_augroup("hbac", {
-	clear = false
-})
-
-local M = {
-	persistant_buffers = {},
-}
-
-M.persist_buffer = function(bufnr)
-	bufnr = bufnr or vim.api.nvim_get_current_buf()
-	M.persistant_buffers[bufnr] = true
-end
-
-M.setup = function(opts)
-	opts = opts or {
-		autoclose = true,
-		threshold = 10
-	}
-
-	vim.api.nvim_create_autocmd({ "BufRead" }, {
-		group = id,
-		pattern = { "*" },
-		callback = function()
-			vim.api.nvim_create_autocmd({ "InsertEnter", "BufModifiedSet" }, {
-				buffer = 0,
-				once = true,
-				callback = function()
-					M.persist_buffer()
-				end
-			})
-		end
-	})
-
-	if not opts.autoclose then
-		return
-	end
-
-	vim.api.nvim_create_autocmd({ "BufEnter" }, {
-		group = id,
-		pattern = { "*" },
-		callback = function()
-			local bufnr = vim.api.nvim_get_current_buf()
-			local buftype = vim.api.nvim_buf_get_option(bufnr, 'buftype')
-			-- if the buffer is not a file - do nothing
-			if buftype ~= "" then
-				return
-			end
-
-			if M.persistant_buffers[M.last] then
-				return
-			end
-
-			local min = 2 ^ 1023
-			local buffers = vim.api.nvim_list_bufs()
-			local num_buffers = 0
-			for _, buf in ipairs(buffers) do
-				local name = vim.api.nvim_buf_get_name(buf)
-				local listed = vim.api.nvim_buf_get_option(buf, 'buflisted')
-				if name ~= "" and listed then
-					num_buffers = num_buffers + 1
-					if not M.persistant_buffers[buf] then
-						min = math.min(min, buf)
-					end
-				end
-			end
-
-			if num_buffers <= opts.threshold then
-				return
-			end
-
-			if min == bufnr then
-				return
-			end
-
-			if min >= 2 ^ 1023 then
-				return
-			end
-
-			vim.api.nvim_buf_delete(min, {})
-		end
-	})
-end
-
-
-local function close_unused()
-	local curbufnr = vim.api.nvim_get_current_buf()
-	local buflist = vim.api.nvim_list_bufs()
-	for _, bufnr in ipairs(buflist) do
-		if vim.bo[bufnr].buflisted and bufnr ~= curbufnr and not M.persistant_buffers[bufnr] then
-			vim.cmd('bd ' .. tostring(bufnr))
-		end
-	end
-end
+local command = require("hbac.command")
 
 return {
-	close_unused = close_unused,
-	setup = M.setup,
+	setup = require("hbac.setup").setup,
+	cmd = command.vim_cmd_func,
+	close_unpinned = command.subcommands.close_unpinned,
+	toggle_pin = command.subcommands.toggle_pin
 }

lua/hbac/setup.lua

@@ -0,0 +1,86 @@
+local command = require("hbac.command")
+local state   = require("hbac.state")
+
+local M = {}
+
+local id = vim.api.nvim_create_augroup("hbac", {
+	clear = false
+})
+
+M.setup = function(opts)
+	opts = opts or {
+		autoclose = true,
+		threshold = 10
+	}
+
+	vim.api.nvim_create_autocmd({ "BufRead" }, {
+		group = id,
+		pattern = { "*" },
+		callback = function()
+			vim.api.nvim_create_autocmd({ "InsertEnter", "BufModifiedSet" }, {
+				buffer = 0,
+				once = true,
+				callback = function()
+					local bufnr = vim.api.nvim_get_current_buf()
+					state.toggle_pin(bufnr)
+				end
+			})
+		end
+	})
+
+	vim.api.nvim_create_user_command(
+		command.vim_cmd_name,
+		function(args)
+			command.vim_cmd_func(args.args)
+		end,
+		command.vim_cmd_opts
+	)
+
+	if not opts.autoclose then
+		return
+	end
+
+	vim.api.nvim_create_autocmd({ "BufEnter" }, {
+		group = id,
+		pattern = { "*" },
+		callback = function()
+			local bufnr = vim.api.nvim_get_current_buf()
+			local buftype = vim.api.nvim_buf_get_option(bufnr, 'buftype')
+			-- if the buffer is not a file - do nothing
+			if buftype ~= "" then
+				return
+			end
+
+			local min = 2 ^ 1023
+			local buffers = vim.api.nvim_list_bufs()
+			local num_buffers = 0
+			for _, buf in ipairs(buffers) do
+				local name = vim.api.nvim_buf_get_name(buf)
+				local listed = vim.api.nvim_buf_get_option(buf, 'buflisted')
+				if name ~= "" and listed then
+					num_buffers = num_buffers + 1
+					if not state.is_pinned(buf) then
+						min = math.min(min, buf)
+					end
+				end
+			end
+
+			if num_buffers <= opts.threshold then
+				return
+			end
+
+			if min == bufnr then
+				return
+			end
+
+			if min >= 2 ^ 1023 then
+				return
+			end
+
+			vim.api.nvim_buf_delete(min, {})
+		end
+	})
+
+end
+
+return M

lua/hbac/state.lua

@@ -0,0 +1,19 @@
+local M = {
+	pinned_buffers = {},
+}
+
+M.toggle_pin = function(bufnr)
+	if M.pinned_buffers[bufnr] == true then
+		M.pinned_buffers[bufnr] = false
+		return "unpinned"
+	end
+
+	M.pinned_buffers[bufnr] = true
+	return "pinned"
+end
+
+M.is_pinned = function(bufnr)
+	return M.pinned_buffers[bufnr] == true
+end
+
+return M