diff --git a/TODO b/TODO
index 5abe9fd..25cc423 100644
--- a/TODO
+++ b/TODO
@@ -16,7 +16,7 @@
 	[ ] that command can be what is selected
 [ ] console: accept input
 [ ] doc: detect file changes with hash
-[ ] add horizontal scroll
+[x] add horizontal scroll
 [ ] add a cross to close tab
 [ ] add context menu to various things
 	[ ] document and selection context menu
@@ -55,3 +55,5 @@
 [ ] show hidden files config and binding
 [ ] syntax: highlight FIXME TODO BUG FIX and IMPROVEMENT keywords
 [ ] do not open doc in new tab if current tab has an unchanged document
+[ ] doc: add auto close brackets and quotes
+[ ] view: implement get_scrollable_size()
diff --git a/data/core/config.lua b/data/core/config.lua
index 663aef1..bcacbca 100644
--- a/data/core/config.lua
+++ b/data/core/config.lua
@@ -4,7 +4,8 @@ config.project_scan_rate = 5
 config.fps = 60
 config.max_log_items = 80
 config.message_timeout = 3
-config.mouse_wheel_scroll = 50 * SCALE
+config.mouse_wheel_scroll_y = 50 * SCALE
+config.mouse_wheel_scroll_x = 30 * SCALE
 config.file_size_limit = 10
 config.ignore_files = "^%."
 config.symbol_pattern = "[%a_][%w_]*"
diff --git a/data/core/rootview.lua b/data/core/rootview.lua
index 389525f..11a7bf2 100644
--- a/data/core/rootview.lua
+++ b/data/core/rootview.lua
@@ -473,10 +473,10 @@ function RootView:on_mouse_moved(x, y, dx, dy)
 end
 
 
-function RootView:on_mouse_wheel(...)
+function RootView:on_mouse_wheel(dy, dx)
   local x, y = self.mouse.x, self.mouse.y
   local node = self.root_node:get_child_overlapping_point(x, y)
-  node.active_view:on_mouse_wheel(...)
+  node.active_view:on_mouse_wheel(dy, dx)
 end
 
 
diff --git a/data/core/view.lua b/data/core/view.lua
index ebd05a0..ef4439f 100644
--- a/data/core/view.lua
+++ b/data/core/view.lua
@@ -3,6 +3,7 @@ local config = require "core.config"
 local style = require "core.style"
 local common = require "core.common"
 local Object = require "core.object"
+local keymap = require "core.keymap"
 
 
 local View = Object:extend()
@@ -44,6 +45,7 @@ function View:get_name()
 end
 
 
+-- TODO: implement this
 function View:get_scrollable_size()
   return math.huge
 end
@@ -96,9 +98,14 @@ function View:on_text_input(text)
 end
 
 
-function View:on_mouse_wheel(y)
+function View:on_mouse_wheel(y, x)
   if self.scrollable then
-    self.scroll.to.y = self.scroll.to.y + y * -config.mouse_wheel_scroll
+    if keymap.modkeys['alt'] then
+      self.scroll.to.x = self.scroll.to.x + y * -config.mouse_wheel_scroll_x
+    else
+      self.scroll.to.y = self.scroll.to.y + y * -config.mouse_wheel_scroll_y
+      self.scroll.to.x = self.scroll.to.x + x * -config.mouse_wheel_scroll_x
+    end
   end
 end
 
@@ -118,8 +125,10 @@ end
 
 
 function View:clamp_scroll_position()
-  local max = self:get_scrollable_size() - self.size.y
-  self.scroll.to.y = common.clamp(self.scroll.to.y, 0, max)
+  local max_y = self:get_scrollable_size() - self.size.y
+  local max_x = self:get_scrollable_size() - self.size.x
+  self.scroll.to.y = common.clamp(self.scroll.to.y, 0, max_y)
+  self.scroll.to.x = common.clamp(self.scroll.to.x, 0, max_x)
 end
 
 
diff --git a/src/api/system.c b/src/api/system.c
index 872800a..ef916c3 100644
--- a/src/api/system.c
+++ b/src/api/system.c
@@ -94,7 +94,7 @@ top:
 		return 2;
 
 	case SDL_MOUSEBUTTONDOWN:
-		if (e.button.button == 1) 
+		if (e.button.button == 1)
 			SDL_CaptureMouse(1);
 		lua_pushstring(L, "mousepressed");
 		lua_pushstring(L, button_name(e.button.button));
@@ -104,7 +104,7 @@ top:
 		return 5;
 
 	case SDL_MOUSEBUTTONUP:
-		if (e.button.button == 1) 
+		if (e.button.button == 1)
 			SDL_CaptureMouse(0);
 		lua_pushstring(L, "mousereleased");
 		lua_pushstring(L, button_name(e.button.button));
@@ -123,7 +123,8 @@ top:
 	case SDL_MOUSEWHEEL:
 		lua_pushstring(L, "mousewheel");
 		lua_pushnumber(L, e.wheel.y);
-		return 2;
+		lua_pushnumber(L, e.wheel.x);
+		return 3;
 
 	default:
 		goto top;
@@ -189,7 +190,7 @@ static int f_set_window_mode(lua_State *L)
 	    n == WIN_FULLSCREEN ? SDL_WINDOW_FULLSCREEN_DESKTOP : 0);
 	if (n == WIN_NORMAL)
 		SDL_RestoreWindow(window);
-	if (n == WIN_MAXIMIZED) 
+	if (n == WIN_MAXIMIZED)
 		SDL_MaximizeWindow(window);
 	return 0;
 }
@@ -226,7 +227,7 @@ static int f_chdir(lua_State *L)
 {
 	const char *path = luaL_checkstring(L, 1);
 	int err = chdir(path);
-	if (err) 
+	if (err)
 		luaL_error(L, "chdir() failed");
 	return 0;
 }
@@ -247,9 +248,9 @@ static int f_list_dir(lua_State *L)
 	int i = 1;
 	struct dirent *entry;
 	while ( (entry = readdir(dir)) ) {
-		if (strcmp(entry->d_name, "." ) == 0) 
+		if (strcmp(entry->d_name, "." ) == 0)
 			continue;
-		if (strcmp(entry->d_name, "..") == 0) 
+		if (strcmp(entry->d_name, "..") == 0)
 			continue;
 		lua_pushstring(L, entry->d_name);
 		lua_rawseti(L, -2, i);
@@ -264,7 +265,7 @@ static int f_absolute_path(lua_State *L)
 {
 	const char *path = luaL_checkstring(L, 1);
 	char *res = realpath(path, NULL);
-	if (!res) 
+	if (!res)
 		return 0;
 	lua_pushstring(L, res);
 	free(res);
@@ -339,7 +340,7 @@ static int f_exec(lua_State *L)
 	size_t len;
 	const char *cmd = luaL_checklstring(L, 1, &len);
 	char *buf = malloc(len + 32);
-	if (!buf) 
+	if (!buf)
 		luaL_error(L, "buffer allocation failed");
 	sprintf(buf, "%s &", cmd);
 	int res = system(buf);
@@ -357,7 +358,7 @@ static int f_fuzzy_match(lua_State *L)
 	int run = 0;
 
 	while (*str && *ptn) {
-		while (*str == ' ') 
+		while (*str == ' ')
 			str++;
 		while (*ptn == ' ')
 			ptn++;
@@ -371,7 +372,7 @@ static int f_fuzzy_match(lua_State *L)
 		}
 		str++;
 	}
-	if (*ptn) 
+	if (*ptn)
 		return 0;
 
 	lua_pushnumber(L, score - (int) strlen(str));