ref(Vars): track local copy of global value

lua/libmodal/Mode.lua

@@ -47,8 +47,8 @@ function Mode:execute_instruction(instruction)
 		vim.api.nvim_command(instruction)
 	end
 
-	self.count:set(0)
-	self.count1:set(1)
+	self.count:set_global(0)
+	self.count1:set_global(1)
 	self:redraw_virtual_cursor()
 end
 
@@ -61,7 +61,7 @@ function Mode:check_input_for_mapping()
 	self.flush_input_timer:stop()
 
 	-- append the latest input to the locally stored input history.
-	self.input_bytes[#self.input_bytes + 1] = self.global_input:get()
+	self.input_bytes[#self.input_bytes + 1] = self.global_input:get_global()
 
 	-- get the command based on the users input.
 	local cmd = self.mappings:get(self.input_bytes)
@@ -115,8 +115,8 @@ function Mode:enter()
 		self.popups:push(utils.Popup.new())
 	end
 
-	self.count:set(0)
-	self.count1:set(1)
+	self.count:set_global(0)
+	self.count1:set_global(1)
 
 	self.local_exit = false
 
@@ -162,7 +162,7 @@ end
 --- @private
 --- @return boolean `true` if the mode's exit was flagged
 function Mode:exit_flagged()
-	return self.local_exit or globals.is_true(self.global_exit:get())
+	return self.local_exit or globals.is_true(self.global_exit:get_global())
 end
 
 --- get input from the user.
@@ -185,13 +185,13 @@ function Mode:get_user_input()
 	end
 
 	-- set the global input variable to the new input.
-	self.global_input:set(user_input)
+	self.global_input:set_global(user_input)
 
 	if ZERO <= user_input and user_input <= NINE then
-		local oldCount = self.count:get()
+		local oldCount = self.count:get_global()
 		local newCount = tonumber(oldCount .. string.char(user_input))
-		self.count:set(newCount)
-		self.count1:set(math.max(1, newCount))
+		self.count:set_global(newCount)
+		self.count1:set_global(math.max(1, newCount))
 	end
 
 	if not self.supress_exit and user_input == globals.ESC_NR then -- the user wants to exit.
@@ -321,7 +321,7 @@ function Mode.new(name, instruction, supress_exit)
 		self.timeouts = utils.Vars.new('timeouts', self.name)
 
 		-- read the correct timeout variable.
-		self.timeouts_enabled = self.timeouts:get() or vim.g.libmodalTimeouts
+		self.timeouts_enabled = self.timeouts:get_global() or vim.g.libmodalTimeouts
 	end
 
 	return self

lua/libmodal/Prompt.lua

@@ -60,10 +60,10 @@ function Prompt:get_user_input()
 	--- @param user_input string
 	local function user_input_callback(user_input)
 		if user_input and user_input:len() > 0 then -- the user actually entered something.
-			self.input:set(user_input)
+			self.input:set_global(user_input)
 			self:execute_instruction(user_input)
 
-			local should_exit = self.exit:get()
+			local should_exit = self.exit:get_global()
 			if should_exit ~= nil then
 				continue_prompt = not should_exit
 			end

lua/libmodal/utils/Vars.lua

@@ -1,23 +1,15 @@
 --- @class libmodal.utils.Vars
 --- @field private mode_name string the highlight group to use when printing `str`
+--- @field private value? unknown the local value of the variable
 --- @field private var_name string the highlight group to use when printing `str`
 local Vars = require('libmodal.utils.classes').new()
 
---- @return unknown `vim.g[self:name()])`
-function Vars:get()
-	return vim.g[self:name()]
-end
-
---- @return string name the global Neovim setting
-function Vars:name()
-	return self.mode_name .. self.var_name
-end
-
 --- create a new set of variables
 --- @param var_name string the name of the key used to refer to this variable in `Vars`.
 --- @param mode_name string the name of the mode
+--- @param default_global? unknown the default global value
 --- @return libmodal.utils.Vars
-function Vars.new(var_name, mode_name)
+function Vars.new(var_name, mode_name, default_global)
 	local self = setmetatable({}, Vars)
 
 	--- @param str_with_spaces string
@@ -42,15 +34,70 @@ function Vars.new(var_name, mode_name)
 
 	self.mode_name = no_spaces(mode_name, string.lower)
 	self.var_name  = 'Mode' .. no_spaces(var_name, string.upper)
+	self.value = nil
+
+	if default_global ~= nil and self:get_global() == nil then
+		self:set_global(default_global)
+	end
 
 	return self
 end
 
 --- @generic T
---- @param val T set `g:{self:name()})` equal to this value
+--- @return T value the local value if it exists, or the global value
+function Vars:get()
+	local local_value = self:get_local()
+	if local_value == nil then
+		return self:get_global()
+	end
+
+	return local_value
+end
+
+--- @generic T
+--- @return T global_value the global value
+function Vars:get_local()
+	return self.value
+end
+
+--- @generic T
+--- @return T global_value the global value
+function Vars:get_global()
+	return vim.g[self:name()]
+end
+
+--- @return string name the global Neovim setting
+function Vars:name()
+	return self.mode_name .. self.var_name
+end
+
+--- NOTE: the local value is only set if not `nil`, for backwards compatibility purposes.
+---       local values did not always exist, and since `get` prefers local values, it may
+---       too-eagerly shadow the global variable.
+--- @param val unknown set local value if it exists, or the global value
 --- @return nil
 function Vars:set(val)
-	vim.api.nvim_set_var(self:name(), val)
+	if self:get_local() == nil then
+		self:set_global(val)
+	else
+		self:set_local(val)
+	end
+end
+
+--- @param val unknown set the local value equal to this
+--- @return nil
+function Vars:set_local(val)
+	self.value = val
+end
+
+--- @param val unknown set the global value equal to this
+--- @return nil
+function Vars:set_global(val)
+	if val == nil then
+		vim.api.nvim_del_var(self:name()) -- because `nvim_set_var('foo', nil)` actually sets 'foo' to `vim.NIL`
+	else
+		vim.api.nvim_set_var(self:name(), val)
+	end
 end
 
 return Vars