fix: use neovim-api for setting the cursor. (closes L3MON4D3#302)

This makes setting the cursor less vulnerable to all kinds of settings,
eg. langmaps or virtualedit, which are unavoidable with "manual" movement
via `hjklG`.

Author: L3MON4D3

lua/luasnip/nodes/functionNode.lua

@@ -4,6 +4,7 @@ local util = require("luasnip.util.util")
 local node_util = require("luasnip.nodes.util")
 local types = require("luasnip.util.types")
 local events = require("luasnip.util.events")
+local tNode = require("luasnip.nodes.textNode")
 
 local function F(fn, args, ...)
 	return FunctionNode:new({
@@ -15,16 +16,7 @@ local function F(fn, args, ...)
 	})
 end
 
-function FunctionNode:input_enter()
-	vim.api.nvim_feedkeys(
-		vim.api.nvim_replace_termcodes("<Esc>", true, false, true),
-		"n",
-		true
-	)
-	util.normal_move_on_insert(self.mark:pos_begin())
-
-	self:event(events.enter)
-end
+FunctionNode.input_enter = tNode.input_enter
 
 function FunctionNode:get_static_text()
 	-- static_text will already have been generated, if possible.

lua/luasnip/nodes/insertNode.lua

@@ -33,11 +33,11 @@ function ExitNode:input_enter(no_move)
 	-- Don't enter node for -1-node, it isn't in the node-table.
 	if self.pos == 0 then
 		InsertNode.input_enter(self, no_move)
-		-- -1-node:
 	else
+		-- -1-node:
 		self:set_mark_rgrav(true, true)
 		if not no_move then
-			local mark_begin_pos = self.mark:pos_begin()
+			local mark_begin_pos = self.mark:pos_begin_raw()
 
 			if vim.fn.mode() == "i" then
 				util.insert_move_on(mark_begin_pos)
@@ -95,36 +95,15 @@ function InsertNode:input_enter(no_move)
 		self.parent:enter_node(self.indx)
 
 		-- SELECT snippet text only when there is text to select (more oft than not there isnt).
-		local mark_begin_pos, mark_end_pos = self.mark:pos_begin_end()
+		local mark_begin_pos, mark_end_pos = self.mark:pos_begin_end_raw()
 		if not util.pos_equal(mark_begin_pos, mark_end_pos) then
-			vim.api.nvim_feedkeys(
-				vim.api.nvim_replace_termcodes("<Esc>", true, false, true),
-				"n",
-				true
-			)
-			util.normal_move_on(mark_begin_pos)
-			vim.api.nvim_feedkeys(
-				vim.api.nvim_replace_termcodes("v", true, false, true),
-				"n",
-				true
-			)
-			-- with `exclusive` set, visual won't include the last cursor-position.
-			-- The cursor has to be moved one column further to account for that.
-			if vim.o.selection == "exclusive" then
-				util.normal_move_on(mark_end_pos)
-			else
-				util.normal_move_before(mark_end_pos)
-			end
-			vim.api.nvim_feedkeys(
-				vim.api.nvim_replace_termcodes("o<C-G>", true, false, true),
-				"n",
-				true
-			)
+			util.any_select(mark_begin_pos, mark_end_pos)
 		else
 			-- if current and target mode is INSERT, there's no reason to leave it.
 			if vim.fn.mode() == "i" then
 				util.insert_move_on(mark_begin_pos)
 			else
+				-- mode might be VISUAL or something else, but <Esc> always leads to normal.
 				vim.api.nvim_feedkeys(
 					vim.api.nvim_replace_termcodes("<Esc>", true, false, true),
 					"n",

lua/luasnip/nodes/textNode.lua

@@ -15,7 +15,7 @@ end
 
 function TextNode:input_enter(no_move)
 	if not no_move then
-		local mark_begin_pos = self.mark:pos_begin()
+		local mark_begin_pos = self.mark:pos_begin_raw()
 		if vim.fn.mode() == "i" then
 			util.insert_move_on(mark_begin_pos)
 		else

lua/luasnip/nodes/util.lua

@@ -92,25 +92,8 @@ local function enter_nodes_between(parent, child, no_move)
 end
 
 local function select_node(node)
-	vim.api.nvim_feedkeys(
-		vim.api.nvim_replace_termcodes("<Esc>", true, false, true),
-		"n",
-		true
-	)
-	-- columns in screencolumns.
-	local node_begin, node_end = node.mark:pos_begin_end()
-	util.normal_move_on(node_begin)
-	vim.api.nvim_feedkeys(
-		vim.api.nvim_replace_termcodes("v", true, false, true),
-		"n",
-		true
-	)
-	util.normal_move_before(node_end)
-	vim.api.nvim_feedkeys(
-		vim.api.nvim_replace_termcodes("o<C-G>", true, false, true),
-		"n",
-		true
-	)
+	local node_begin, node_end = node.mark:pos_begin_end_raw()
+	util.any_select(node_begin, node_end)
 end
 
 local function print_dict(dict)

lua/luasnip/util/util.lua

@@ -104,89 +104,74 @@ local function bytecol_to_utfcol(pos)
 	return { pos[1], vim.str_utfindex(line[1] or "", pos[2]) }
 end
 
-local function normal_move_before(new_cur_pos)
-	-- +1: indexing
-	if new_cur_pos[2] - 1 > 0 then
-		local keys = vim.api.nvim_replace_termcodes(
-			tostring(new_cur_pos[1] + 1)
-				.. "G0"
-				.. tostring(new_cur_pos[2] - 1)
-				.. "<Right>",
-			true,
-			false,
-			true
-		)
-		-- passing only "n" doesn't open folds (:h feedkeys).
-		vim.api.nvim_feedkeys(keys, "nt", true)
-	elseif new_cur_pos[2] - 1 == 0 then
-		vim.api.nvim_feedkeys(tostring(new_cur_pos[1] + 1) .. "G0", "nt", true)
-	else
-		-- column is 0, includes end of previous line. Move there.
-		vim.api.nvim_feedkeys(tostring(new_cur_pos[1]) .. "G$", "nt", true)
-	end
+local function replace_feedkeys(keys, opts)
+	vim.api.nvim_feedkeys(
+		vim.api.nvim_replace_termcodes(keys, true, false, true),
+		-- folds are opened manually now, no need to pass t.
+		-- n prevents langmap from interfering.
+		opts or "n",
+		true
+	)
 end
 
-local function normal_move_on(new_cur_pos)
-	if new_cur_pos[2] ~= 0 then
-		local keys = vim.api.nvim_replace_termcodes(
-			tostring(new_cur_pos[1] + 1)
-				.. "G0"
-				.. tostring(new_cur_pos[2])
-				-- open folds!
-				.. "<Right>",
-			true,
-			false,
-			true
-		)
-		-- passing only "n" doesn't open folds (:h feedkeys).
-		vim.api.nvim_feedkeys(keys, "nt", true)
-	else
-		vim.api.nvim_feedkeys(tostring(new_cur_pos[1] + 1) .. "G0", "nt", true)
+-- pos: (0,0)-indexed.
+local function cursor_set_keys(pos, before)
+	if before then
+		if pos[2] == 0 then
+			pos[1] = pos[1] - 1
+			-- pos2 is set to last columnt of previous line.
+			-- # counts bytes, but win_set_cursor expects bytes, so all's good.
+			pos[2] = #vim.api.nvim_buf_get_lines(
+					0,
+					pos[1],
+					pos[1] + 1,
+					false
+				)[1]
+		else
+			pos[2] = pos[2] - 1
+		end
 	end
+
+	return "<cmd>lua vim.api.nvim_win_set_cursor(0,{"
+		-- +1, win_set_cursor starts at 1.
+		.. pos[1] + 1
+		.. ","
+		-- -1 works for multibyte because of rounding, apparently.
+		.. pos[2]
+		.. "})"
+		.. "<cr><cmd>:silent! foldopen!<cr>"
+end
+
+-- any for any mode.
+-- other functions prefixed with eg. normal have to be in that mode, the
+-- initial esc removes that need.
+local function any_select(b, e)
+	-- stylua: ignore
+	replace_feedkeys(
+		-- this esc -> movement sometimes leads to a slight flicker
+		-- TODO: look into preventing that reliably.
+		-- simple move -> <esc>v isn't possible, leaving insert moves the
+		-- cursor, maybe do check for mode beforehand.
+		"<esc>"
+		.. cursor_set_keys(b)
+		.. "v"
+		.. (vim.o.selection == "exclusive" and
+			cursor_set_keys(e) or
+			-- set before
+			cursor_set_keys(e, true))
+		.. "o<C-G>" )
 end
 
 local function normal_move_on_insert(new_cur_pos)
-	local keys = vim.api.nvim_replace_termcodes(
-		tostring(new_cur_pos[1] + 1)
-			-- open folds!
-			.. "G0i"
-			.. string.rep("<Right>", new_cur_pos[2]),
-		true,
-		false,
-		true
-	)
-	-- passing only "n" doesn't open folds (:h feedkeys).
-	vim.api.nvim_feedkeys(keys, "nt", true)
+	-- moving in normal and going into insert is kind of annoying, eg. when the
+	-- cursor is, in normal, on a tab, i will set it on the beginning of the
+	-- tab. There's more problems, but this is very safe.
+	replace_feedkeys("i" .. cursor_set_keys(new_cur_pos))
 end
 
 local function insert_move_on(new_cur_pos)
-	local current_line = get_cursor_0ind()[1]
-
-	-- only compute diff for lines, seems safer and may even be faster because
-	-- the current column isn't required (cursor returns in bytes, calculating
-	-- columns from bytes costs too).
-	local direction, count
-	if current_line > new_cur_pos[1] then
-		-- current line is lower on screen, we need to move up.
-		direction = "<Up>"
-		count = current_line - new_cur_pos[1]
-	else
-		direction = "<Down>"
-		count = new_cur_pos[1] - current_line
-	end
-
-	-- stylua: ignore
-	local try =
-		-- move cursor to first column
-		"<Home>"
-		-- move to correct line.
-		.. direction:rep(count)
-		-- move to correct column
-		.. string.rep("<Right>", new_cur_pos[2])
-
-	local keys = vim.api.nvim_replace_termcodes(try, true, false, true)
-	-- passing only "n" doesn't open folds (:h feedkeys).
-	vim.api.nvim_feedkeys(keys, "nt", true)
+	-- maybe feedkeys this too.
+	set_cursor_0ind(new_cur_pos)
 end
 
 local function multiline_equal(t1, t2)
@@ -569,10 +554,9 @@ return {
 	get_cursor_0ind = get_cursor_0ind,
 	set_cursor_0ind = set_cursor_0ind,
 	move_to_mark = move_to_mark,
-	normal_move_before = normal_move_before,
-	normal_move_on = normal_move_on,
 	normal_move_on_insert = normal_move_on_insert,
 	insert_move_on = insert_move_on,
+	any_select = any_select,
 	remove_n_before_cur = remove_n_before_cur,
 	get_current_line_to_cursor = get_current_line_to_cursor,
 	mark_pos_equal = mark_pos_equal,