diff --git a/musicdb-client/Cargo.toml b/musicdb-client/Cargo.toml
index afbf1c9..9965443 100644
--- a/musicdb-client/Cargo.toml
+++ b/musicdb-client/Cargo.toml
@@ -12,12 +12,11 @@ directories = "5.0.1"
 regex = "1.9.3"
 speedy2d = { version = "1.12.0", optional = true }
 toml = "0.7.6"
-# mers_lib = { version = "0.3.2", optional = true }
-# musicdb-mers = { version = "0.1.0", path = "../musicdb-mers", optional = true }
+musicdb-mers = { version = "0.1.0", path = "../musicdb-mers", optional = true }
 uianimator = "0.1.1"
 
 [features]
-default = ["gui", "playback"]
+default = ["gui", "playback", "merscfg"]
 # gui:
 #   enables the gui modes
 # merscfg:
@@ -27,6 +26,6 @@ default = ["gui", "playback"]
 # playback:
 #   enables syncplayer modes, where the client mirrors the server's playback
 gui = ["speedy2d"]
-# merscfg = ["mers_lib", "musicdb-mers", "speedy2d"]
-# mers = ["mers_lib", "musicdb-mers"]
+merscfg = ["mers", "speedy2d"]
+mers = ["musicdb-mers"]
 playback = ["musicdb-lib/playback"]
diff --git a/musicdb-client/src/gui.rs b/musicdb-client/src/gui.rs
index 8469742..6b1bff7 100755
--- a/musicdb-client/src/gui.rs
+++ b/musicdb-client/src/gui.rs
@@ -299,7 +299,7 @@ pub struct Gui {
     pub size: UVec2,
     pub mouse_pos: Vec2,
     pub font: Font,
-    pub keybinds: BTreeMap<KeyBinding, KeyActionId>,
+    pub keybinds: BTreeMap<KeyBinding, KeyActionRef>,
     pub key_actions: KeyActions,
     pub covers: Option<HashMap<CoverId, GuiServerImage>>,
     pub custom_images: Option<HashMap<String, GuiServerImage>>,
@@ -351,11 +351,11 @@ impl Gui {
                 }
             }
             Ok(Err(e)) => {
-                eprintln!("Error loading merscfg:\n{e}");
+                eprintln!("Error loading merscfg:\n{}", e.display_term());
             }
             Ok(Ok(Err((m, e)))) => {
                 if let Some(e) = e {
-                    eprintln!("Error loading merscfg:\n{m}\n{e}");
+                    eprintln!("Error loading merscfg:\n{m}\n{}", e.display_term());
                 } else {
                     eprintln!("Error loading merscfg:\n{m}");
                 }
@@ -530,28 +530,39 @@ pub trait GuiElem {
     /// handles drawing.
     fn draw(&mut self, info: &mut DrawInfo, g: &mut Graphics2D) {}
     /// an event that is invoked whenever a mouse button is pressed on the element.
-    fn mouse_down(&mut self, button: MouseButton) -> Vec<GuiAction> {
+    fn mouse_down(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
         Vec::with_capacity(0)
     }
     /// an event that is invoked whenever a mouse button that was pressed on the element is released anywhere.
-    fn mouse_up(&mut self, button: MouseButton) -> Vec<GuiAction> {
+    fn mouse_up(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
         Vec::with_capacity(0)
     }
     /// an event that is invoked after a mouse button was pressed and released on the same GUI element.
-    fn mouse_pressed(&mut self, button: MouseButton) -> Vec<GuiAction> {
+    fn mouse_pressed(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
         Vec::with_capacity(0)
     }
-    fn mouse_wheel(&mut self, diff: f32) -> Vec<GuiAction> {
+    fn mouse_wheel(&mut self, e: &mut EventInfo, diff: f32) -> Vec<GuiAction> {
         Vec::with_capacity(0)
     }
-    fn char_watch(&mut self, modifiers: ModifiersState, key: char) -> Vec<GuiAction> {
+    fn char_watch(
+        &mut self,
+        e: &mut EventInfo,
+        modifiers: ModifiersState,
+        key: char,
+    ) -> Vec<GuiAction> {
         Vec::with_capacity(0)
     }
-    fn char_focus(&mut self, modifiers: ModifiersState, key: char) -> Vec<GuiAction> {
+    fn char_focus(
+        &mut self,
+        e: &mut EventInfo,
+        modifiers: ModifiersState,
+        key: char,
+    ) -> Vec<GuiAction> {
         Vec::with_capacity(0)
     }
     fn key_watch(
         &mut self,
+        e: &mut EventInfo,
         modifiers: ModifiersState,
         down: bool,
         key: Option<VirtualKeyCode>,
@@ -561,6 +572,7 @@ pub trait GuiElem {
     }
     fn key_focus(
         &mut self,
+        e: &mut EventInfo,
         modifiers: ModifiersState,
         down: bool,
         key: Option<VirtualKeyCode>,
@@ -569,12 +581,24 @@ pub trait GuiElem {
         Vec::with_capacity(0)
     }
     /// When something is dragged and released over this element
-    fn dragged(&mut self, dragged: Dragging) -> Vec<GuiAction> {
+    fn dragged(&mut self, e: &mut EventInfo, dragged: Dragging) -> Vec<GuiAction> {
         Vec::with_capacity(0)
     }
     fn updated_library(&mut self) {}
     fn updated_queue(&mut self) {}
 }
+pub struct EventInfo(bool);
+impl EventInfo {
+    pub fn can_take(&self) -> bool {
+        self.0
+    }
+    pub fn take(&mut self) -> bool {
+        std::mem::replace(&mut self.0, false)
+    }
+    fn new() -> Self {
+        Self(true)
+    }
+}
 impl<T: GuiElem + ?Sized> GuiElemInternal for T {}
 pub(crate) trait GuiElemInternal: GuiElem {
     fn _draw(&mut self, info: &mut DrawInfo, g: &mut Graphics2D) {
@@ -625,38 +649,49 @@ pub(crate) trait GuiElemInternal: GuiElem {
         self.config_mut().pixel_pos = std::mem::replace(&mut info.pos, ppos);
     }
     /// recursively applies the function to all gui elements below and including this one
-    fn _recursive_all(&mut self, f: &mut dyn FnMut(&mut dyn GuiElem)) {
-        f(self.elem_mut());
-        for c in self.children() {
-            c._recursive_all(f);
+    fn _recursive_all(&mut self, allow_deactivated: bool, f: &mut dyn FnMut(&mut dyn GuiElem)) {
+        if self.config().enabled || allow_deactivated {
+            f(self.elem_mut());
+            for c in self.children() {
+                c._recursive_all(allow_deactivated, f);
+            }
         }
     }
     fn _mouse_event(
         &mut self,
-        condition: &mut dyn FnMut(&mut dyn GuiElem) -> Option<Vec<GuiAction>>,
+        e: &mut EventInfo,
+        allow_deactivated: bool,
+        condition: &mut dyn FnMut(&mut dyn GuiElem, &mut EventInfo) -> Option<Vec<GuiAction>>,
         pos: Vec2,
     ) -> Option<Vec<GuiAction>> {
-        for c in &mut self.children() {
-            if c.config().enabled {
-                if c.config().pixel_pos.contains(pos) {
-                    if let Some(v) = c._mouse_event(condition, pos) {
-                        return Some(v);
+        if self.config().enabled || allow_deactivated {
+            for c in &mut self.children() {
+                if c.config().enabled {
+                    if c.config().pixel_pos.contains(pos) {
+                        if let Some(v) = c._mouse_event(e, allow_deactivated, condition, pos) {
+                            return Some(v);
+                        }
                     }
                 }
             }
+            condition(self.elem_mut(), e)
+        } else {
+            None
         }
-        condition(self.elem_mut())
     }
     fn _release_drag(
         &mut self,
+        e: &mut EventInfo,
         dragged: &mut Option<Dragging>,
         pos: Vec2,
     ) -> Option<Vec<GuiAction>> {
         self._mouse_event(
-            &mut |v| {
+            e,
+            false,
+            &mut |v, e| {
                 if v.config().drag_target {
                     if let Some(d) = dragged.take() {
-                        return Some(v.dragged(d));
+                        return Some(v.dragged(e, d));
                     }
                 }
                 None
@@ -666,13 +701,16 @@ pub(crate) trait GuiElemInternal: GuiElem {
     }
     fn _mouse_button(
         &mut self,
+        e: &mut EventInfo,
         button: MouseButton,
         down: bool,
         pos: Vec2,
     ) -> Option<Vec<GuiAction>> {
         if down {
             self._mouse_event(
-                &mut |v: &mut dyn GuiElem| {
+                e,
+                !down,
+                &mut |v: &mut dyn GuiElem, e| {
                     if v.config().mouse_events {
                         match button {
                             MouseButton::Left => {
@@ -689,7 +727,7 @@ pub(crate) trait GuiElemInternal: GuiElem {
                             }
                             MouseButton::Other(_) => {}
                         }
-                        Some(v.mouse_down(button))
+                        Some(v.mouse_down(e, button))
                     } else {
                         None
                     }
@@ -699,14 +737,16 @@ pub(crate) trait GuiElemInternal: GuiElem {
         } else {
             let mut vec = vec![];
             if let Some(a) = self._mouse_event(
-                &mut |v: &mut dyn GuiElem| {
+                e,
+                !down,
+                &mut |v: &mut dyn GuiElem, e| {
                     let down = v.config().mouse_down;
                     if v.config().mouse_events
                         && ((button == MouseButton::Left && down.0)
                             || (button == MouseButton::Middle && down.1)
                             || (button == MouseButton::Right && down.2))
                     {
-                        Some(v.mouse_pressed(button))
+                        Some(v.mouse_pressed(e, button))
                     } else {
                         None
                     }
@@ -715,7 +755,7 @@ pub(crate) trait GuiElemInternal: GuiElem {
             ) {
                 vec.extend(a);
             };
-            self._recursive_all(&mut |v| {
+            self._recursive_all(!down, &mut |v| {
                 if v.config().mouse_events {
                     match button {
                         MouseButton::Left => {
@@ -732,17 +772,19 @@ pub(crate) trait GuiElemInternal: GuiElem {
                         }
                         MouseButton::Other(_) => {}
                     }
-                    vec.extend(v.mouse_up(button));
+                    vec.extend(v.mouse_up(e, button));
                 }
             });
             Some(vec)
         }
     }
-    fn _mouse_wheel(&mut self, diff: f32, pos: Vec2) -> Option<Vec<GuiAction>> {
+    fn _mouse_wheel(&mut self, e: &mut EventInfo, diff: f32, pos: Vec2) -> Option<Vec<GuiAction>> {
         self._mouse_event(
-            &mut |v| {
+            e,
+            false,
+            &mut |v, e| {
                 if v.config().scroll_events {
-                    Some(v.mouse_wheel(diff))
+                    Some(v.mouse_wheel(e, diff))
                 } else {
                     None
                 }
@@ -752,29 +794,45 @@ pub(crate) trait GuiElemInternal: GuiElem {
     }
     fn _keyboard_event(
         &mut self,
-        f_focus: &mut dyn FnMut(&mut dyn GuiElem, &mut Vec<GuiAction>),
-        f_watch: &mut dyn FnMut(&mut dyn GuiElem, &mut Vec<GuiAction>),
+        e: &mut EventInfo,
+        allow_deactivated: bool,
+        f_focus: &mut dyn FnMut(&mut dyn GuiElem, &mut EventInfo, &mut Vec<GuiAction>),
+        f_watch: &mut dyn FnMut(&mut dyn GuiElem, &mut EventInfo, &mut Vec<GuiAction>),
     ) -> Vec<GuiAction> {
         let mut o = vec![];
-        self._keyboard_event_inner(&mut Some(f_focus), f_watch, &mut o, true);
+        self._keyboard_event_inner_focus(e, allow_deactivated, f_focus, &mut o);
+        self._keyboard_event_inner_nofocus(e, allow_deactivated, f_watch, &mut o);
         o
     }
-    fn _keyboard_event_inner(
+    fn _keyboard_event_inner_nofocus(
         &mut self,
-        f_focus: &mut Option<&mut dyn FnMut(&mut dyn GuiElem, &mut Vec<GuiAction>)>,
-        f_watch: &mut dyn FnMut(&mut dyn GuiElem, &mut Vec<GuiAction>),
+        e: &mut EventInfo,
+        allow_deactivated: bool,
+        f_watch: &mut dyn FnMut(&mut dyn GuiElem, &mut EventInfo, &mut Vec<GuiAction>),
         events: &mut Vec<GuiAction>,
-        focus: bool,
     ) {
-        f_watch(self.elem_mut(), events);
-        let focus_index = self.config().keyboard_focus_index;
-        for (i, child) in self.children().enumerate() {
-            child._keyboard_event_inner(f_focus, f_watch, events, focus && i == focus_index);
+        if self.config().enabled || allow_deactivated {
+            for child in self.children() {
+                child._keyboard_event_inner_nofocus(e, allow_deactivated, f_watch, events);
+            }
+            f_watch(self.elem_mut(), e, events);
         }
-        if focus {
-            // we have focus and no child has consumed f_focus
-            if let Some(f) = f_focus.take() {
-                f(self.elem_mut(), events)
+    }
+    fn _keyboard_event_inner_focus(
+        &mut self,
+        e: &mut EventInfo,
+        allow_deactivated: bool,
+        f_focus: &mut dyn FnMut(&mut dyn GuiElem, &mut EventInfo, &mut Vec<GuiAction>),
+        events: &mut Vec<GuiAction>,
+    ) {
+        if e.can_take() && (self.config().enabled || allow_deactivated) {
+            let i = self.config().keyboard_focus_index;
+            if let Some(child) = self.children().nth(i) {
+                child._keyboard_event_inner_focus(e, allow_deactivated, f_focus, events);
+            }
+            if e.can_take() {
+                // we have focus and no child has taken the event
+                f_focus(self.elem_mut(), e, events);
             }
         }
     }
@@ -880,44 +938,56 @@ impl<T: GuiElemWrapper> GuiElem for T {
     fn draw(&mut self, info: &mut DrawInfo, g: &mut Graphics2D) {
         self.as_elem_mut().draw(info, g)
     }
-    fn mouse_down(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        self.as_elem_mut().mouse_down(button)
+    fn mouse_down(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        self.as_elem_mut().mouse_down(e, button)
     }
-    fn mouse_up(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        self.as_elem_mut().mouse_up(button)
+    fn mouse_up(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        self.as_elem_mut().mouse_up(e, button)
     }
-    fn mouse_pressed(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        self.as_elem_mut().mouse_pressed(button)
+    fn mouse_pressed(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        self.as_elem_mut().mouse_pressed(e, button)
     }
-    fn mouse_wheel(&mut self, diff: f32) -> Vec<GuiAction> {
-        self.as_elem_mut().mouse_wheel(diff)
+    fn mouse_wheel(&mut self, e: &mut EventInfo, diff: f32) -> Vec<GuiAction> {
+        self.as_elem_mut().mouse_wheel(e, diff)
     }
-    fn char_watch(&mut self, modifiers: ModifiersState, key: char) -> Vec<GuiAction> {
-        self.as_elem_mut().char_watch(modifiers, key)
+    fn char_watch(
+        &mut self,
+        e: &mut EventInfo,
+        modifiers: ModifiersState,
+        key: char,
+    ) -> Vec<GuiAction> {
+        self.as_elem_mut().char_watch(e, modifiers, key)
     }
-    fn char_focus(&mut self, modifiers: ModifiersState, key: char) -> Vec<GuiAction> {
-        self.as_elem_mut().char_focus(modifiers, key)
+    fn char_focus(
+        &mut self,
+        e: &mut EventInfo,
+        modifiers: ModifiersState,
+        key: char,
+    ) -> Vec<GuiAction> {
+        self.as_elem_mut().char_focus(e, modifiers, key)
     }
     fn key_watch(
         &mut self,
+        e: &mut EventInfo,
         modifiers: ModifiersState,
         down: bool,
         key: Option<VirtualKeyCode>,
         scan: KeyScancode,
     ) -> Vec<GuiAction> {
-        self.as_elem_mut().key_watch(modifiers, down, key, scan)
+        self.as_elem_mut().key_watch(e, modifiers, down, key, scan)
     }
     fn key_focus(
         &mut self,
+        e: &mut EventInfo,
         modifiers: ModifiersState,
         down: bool,
         key: Option<VirtualKeyCode>,
         scan: KeyScancode,
     ) -> Vec<GuiAction> {
-        self.as_elem_mut().key_focus(modifiers, down, key, scan)
+        self.as_elem_mut().key_focus(e, modifiers, down, key, scan)
     }
-    fn dragged(&mut self, dragged: Dragging) -> Vec<GuiAction> {
-        self.as_elem_mut().dragged(dragged)
+    fn dragged(&mut self, e: &mut EventInfo, dragged: Dragging) -> Vec<GuiAction> {
+        self.as_elem_mut().dragged(e, dragged)
     }
     fn updated_library(&mut self) {
         self.as_elem_mut().updated_library()
@@ -1106,9 +1176,13 @@ impl Default for GuiElemCfg {
 pub enum GuiAction {
     OpenMain,
     /// Add a key action (and optionally bind it) and then call the given function
-    AddKeybind(Option<KeyBinding>, KeyAction, Box<dyn FnOnce(KeyActionId)>),
+    AddKeybind(
+        Option<(KeyBinding, bool)>,
+        KeyAction,
+        Box<dyn FnOnce(KeyActionId)>,
+    ),
     /// Binds the action to the keybinding, or unbinds it entirely
-    SetKeybind(KeyActionId, Option<KeyBinding>),
+    SetKeybind(KeyActionId, Option<(KeyBinding, bool)>),
     ForceIdle,
     /// false -> prevent idling, true -> end idling even if already idle
     EndIdle(bool),
@@ -1205,8 +1279,8 @@ impl Gui {
             }
             GuiAction::AddKeybind(bind, action, func) => {
                 let id = self.key_actions.add(action);
-                if let Some(bind) = bind {
-                    self.keybinds.insert(bind, id);
+                if let Some((bind, priority)) = bind {
+                    self.keybinds.insert(bind, id.with_priority(priority));
                 }
                 func(id);
             }
@@ -1226,8 +1300,8 @@ impl Gui {
                 {
                     self.keybinds.remove(&b);
                 }
-                if let Some(bind) = bind {
-                    self.keybinds.insert(bind, action);
+                if let Some((bind, priority)) = bind {
+                    self.keybinds.insert(bind, action.with_priority(priority));
                 }
             }
             GuiAction::SendToServer(cmd) => {
@@ -1283,7 +1357,7 @@ impl Gui {
             GuiAction::SetLineHeight(h) => {
                 self.line_height = h;
                 self.gui
-                    ._recursive_all(&mut |e| e.config_mut().redraw = true);
+                    ._recursive_all(true, &mut |e| e.config_mut().redraw = true);
             }
             GuiAction::LoadCover(id) => {
                 self.covers
@@ -1447,7 +1521,10 @@ impl WindowHandler<GuiEvent> for Gui {
         }
     }
     fn on_mouse_button_down(&mut self, helper: &mut WindowHelper<GuiEvent>, button: MouseButton) {
-        if let Some(a) = self.gui._mouse_button(button, true, self.mouse_pos.clone()) {
+        if let Some(a) =
+            self.gui
+                ._mouse_button(&mut EventInfo::new(), button, true, self.mouse_pos.clone())
+        {
             for a in a {
                 self.exec_gui_action(a)
             }
@@ -1458,7 +1535,10 @@ impl WindowHandler<GuiEvent> for Gui {
         if self.dragging.is_some() {
             let (dr, _) = self.dragging.take().unwrap();
             let mut opt = Some(dr);
-            if let Some(a) = self.gui._release_drag(&mut opt, self.mouse_pos.clone()) {
+            if let Some(a) =
+                self.gui
+                    ._release_drag(&mut EventInfo::new(), &mut opt, self.mouse_pos.clone())
+            {
                 for a in a {
                     self.exec_gui_action(a)
                 }
@@ -1476,9 +1556,9 @@ impl WindowHandler<GuiEvent> for Gui {
                 }
             }
         }
-        if let Some(a) = self
-            .gui
-            ._mouse_button(button, false, self.mouse_pos.clone())
+        if let Some(a) =
+            self.gui
+                ._mouse_button(&mut EventInfo::new(), button, false, self.mouse_pos.clone())
         {
             for a in a {
                 self.exec_gui_action(a)
@@ -1506,7 +1586,10 @@ impl WindowHandler<GuiEvent> for Gui {
                     * self.last_height
             }
         };
-        if let Some(a) = self.gui._mouse_wheel(dist, self.mouse_pos.clone()) {
+        if let Some(a) = self
+            .gui
+            ._mouse_wheel(&mut EventInfo::new(), dist, self.mouse_pos.clone())
+        {
             for a in a {
                 self.exec_gui_action(a)
             }
@@ -1516,14 +1599,16 @@ impl WindowHandler<GuiEvent> for Gui {
     fn on_keyboard_char(&mut self, helper: &mut WindowHelper<GuiEvent>, unicode_codepoint: char) {
         helper.request_redraw();
         for a in self.gui._keyboard_event(
-            &mut |e, a| {
-                if e.config().keyboard_events_focus {
-                    a.append(&mut e.char_focus(self.modifiers.clone(), unicode_codepoint));
+            &mut EventInfo::new(),
+            false,
+            &mut |g, e, a| {
+                if g.config().keyboard_events_focus {
+                    a.append(&mut g.char_focus(e, self.modifiers.clone(), unicode_codepoint));
                 }
             },
-            &mut |e, a| {
-                if e.config().keyboard_events_watch {
-                    a.append(&mut e.char_watch(self.modifiers.clone(), unicode_codepoint));
+            &mut |g, e, a| {
+                if g.config().keyboard_events_watch {
+                    a.append(&mut g.char_watch(e, self.modifiers.clone(), unicode_codepoint));
                 }
             },
         ) {
@@ -1543,9 +1628,12 @@ impl WindowHandler<GuiEvent> for Gui {
             }
         }
         for a in self.gui._keyboard_event(
-            &mut |e, a| {
-                if e.config().keyboard_events_focus {
-                    a.append(&mut e.key_focus(
+            &mut EventInfo::new(),
+            false,
+            &mut |g, e, a| {
+                if g.config().keyboard_events_focus {
+                    a.append(&mut g.key_focus(
+                        e,
                         self.modifiers.clone(),
                         true,
                         virtual_key_code,
@@ -1553,9 +1641,10 @@ impl WindowHandler<GuiEvent> for Gui {
                     ));
                 }
             },
-            &mut |e, a| {
-                if e.config().keyboard_events_watch {
-                    a.append(&mut e.key_watch(
+            &mut |g, e, a| {
+                if g.config().keyboard_events_watch {
+                    a.append(&mut g.key_watch(
+                        e,
                         self.modifiers.clone(),
                         true,
                         virtual_key_code,
@@ -1575,21 +1664,30 @@ impl WindowHandler<GuiEvent> for Gui {
     ) {
         helper.request_redraw();
         // handle keybinds unless settings are open, opening or closing
+        let mut e = EventInfo::new();
+        let mut post_action = None;
         if self.gui.settings.0 == false && self.gui.settings.1.is_none() {
             if let Some(key) = virtual_key_code {
                 let keybind = KeyBinding::new(&self.modifiers, key);
                 if let Some(action) = self.keybinds.get(&keybind) {
-                    for a in self.key_actions.get(action).execute() {
-                        self.exec_gui_action(a);
+                    if action.has_priority() {
+                        e.take();
+                        for a in self.key_actions.get(&action.id()).execute() {
+                            self.exec_gui_action(a);
+                        }
+                    } else {
+                        post_action = Some(action.id());
                     }
-                    return;
                 }
             }
         }
         for a in self.gui._keyboard_event(
-            &mut |e, a| {
-                if e.config().keyboard_events_focus {
-                    a.append(&mut e.key_focus(
+            &mut EventInfo::new(),
+            true,
+            &mut |g, e, a| {
+                if g.config().keyboard_events_focus {
+                    a.append(&mut g.key_focus(
+                        e,
                         self.modifiers.clone(),
                         false,
                         virtual_key_code,
@@ -1597,9 +1695,10 @@ impl WindowHandler<GuiEvent> for Gui {
                     ));
                 }
             },
-            &mut |e, a| {
-                if e.config().keyboard_events_watch {
-                    a.append(&mut e.key_watch(
+            &mut |g, e, a| {
+                if g.config().keyboard_events_watch {
+                    a.append(&mut g.key_watch(
+                        e,
                         self.modifiers.clone(),
                         false,
                         virtual_key_code,
@@ -1610,6 +1709,13 @@ impl WindowHandler<GuiEvent> for Gui {
         ) {
             self.exec_gui_action(a);
         }
+        if let Some(post_action) = post_action.take() {
+            if e.take() {
+                for a in self.key_actions.get(&post_action).execute() {
+                    self.exec_gui_action(a);
+                }
+            }
+        }
     }
     fn on_keyboard_modifiers_changed(
         &mut self,
@@ -1636,7 +1742,7 @@ impl WindowHandler<GuiEvent> for Gui {
                 } else {
                     eprintln!("WARN: Skipping call to merscfg's library_updated because gui_config is not available");
                 }
-                self.gui._recursive_all(&mut |e| e.updated_library());
+                self.gui._recursive_all(true, &mut |e| e.updated_library());
                 helper.request_redraw();
             }
             GuiEvent::UpdatedQueue => {
@@ -1647,7 +1753,7 @@ impl WindowHandler<GuiEvent> for Gui {
                 } else {
                     eprintln!("WARN: Skipping call to merscfg's queue_updated because gui_config is not available");
                 }
-                self.gui._recursive_all(&mut |e| e.updated_queue());
+                self.gui._recursive_all(true, &mut |e| e.updated_queue());
                 helper.request_redraw();
             }
             GuiEvent::Exit => helper.terminate_loop(),
@@ -1660,7 +1766,7 @@ impl WindowHandler<GuiEvent> for Gui {
     fn on_resize(&mut self, _helper: &mut WindowHelper<GuiEvent>, size_pixels: UVec2) {
         self.size = size_pixels;
         self.gui
-            ._recursive_all(&mut |e| e.config_mut().redraw = true);
+            ._recursive_all(true, &mut |e| e.config_mut().redraw = true);
     }
 }
 
@@ -1807,10 +1913,29 @@ impl KeyAction {
 pub struct KeyActions(Vec<KeyAction>);
 #[derive(Clone, Copy)]
 pub struct KeyActionId(usize);
+#[derive(Clone, Copy)]
+pub struct KeyActionRef(usize, bool);
 impl KeyActionId {
     pub fn get_index(&self) -> usize {
         self.0
     }
+    pub fn with_priority(&self, priority: bool) -> KeyActionRef {
+        KeyActionRef(self.0, priority)
+    }
+}
+impl KeyActionRef {
+    pub fn get_index(&self) -> usize {
+        self.0
+    }
+    pub fn id(&self) -> KeyActionId {
+        KeyActionId(self.0)
+    }
+    pub fn has_priority(&self) -> bool {
+        self.1
+    }
+    pub fn set_priority(&mut self, priority: bool) {
+        self.1 = priority;
+    }
 }
 impl KeyActions {
     pub fn add(&mut self, action: KeyAction) -> KeyActionId {
diff --git a/musicdb-client/src/gui_base.rs b/musicdb-client/src/gui_base.rs
index e4de396..d170e72 100755
--- a/musicdb-client/src/gui_base.rs
+++ b/musicdb-client/src/gui_base.rs
@@ -3,7 +3,7 @@ use std::{sync::Arc, time::Instant};
 use speedy2d::{color::Color, dimen::Vec2, shape::Rectangle, window::MouseButton};
 
 use crate::{
-    gui::{DrawInfo, GuiAction, GuiElem, GuiElemCfg, GuiElemChildren},
+    gui::{DrawInfo, EventInfo, GuiAction, GuiElem, GuiElemCfg, GuiElemChildren},
     gui_text::Label,
 };
 
@@ -291,20 +291,26 @@ impl<C: GuiElemChildren + 'static> GuiElem for ScrollBox<C> {
             );
         }
     }
-    fn mouse_wheel(&mut self, diff: f32) -> Vec<crate::gui::GuiAction> {
-        self.scroll_target = (self.scroll_target
-            - self.size_unit.from_abs(diff as f32, self.last_height_px))
-        .max(0.0);
+    fn mouse_wheel(&mut self, e: &mut EventInfo, diff: f32) -> Vec<crate::gui::GuiAction> {
+        let nst = (self.scroll_target - self.size_unit.from_abs(diff as f32, self.last_height_px))
+            .max(0.0);
+        // only take the event if this would actually scroll, and only scroll if we can actually take the event
+        if nst != self.scroll_target && e.take() {
+            self.scroll_target = nst;
+        }
         Vec::with_capacity(0)
     }
-    fn mouse_down(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        if button == MouseButton::Left && self.mouse_in_scrollbar {
+    fn mouse_down(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        if button == MouseButton::Left && self.mouse_in_scrollbar && e.take() {
             self.mouse_scrolling = true;
         }
         vec![]
     }
-    fn mouse_up(&mut self, button: MouseButton) -> Vec<GuiAction> {
+    fn mouse_up(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
         if button == MouseButton::Left {
+            if self.mouse_scrolling {
+                e.take();
+            }
             self.mouse_scrolling = false;
         }
         vec![]
@@ -372,8 +378,8 @@ impl<C: GuiElemChildren + 'static> GuiElem for Button<C> {
     fn elem_mut(&mut self) -> &mut dyn GuiElem {
         self
     }
-    fn mouse_pressed(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        if button == MouseButton::Left {
+    fn mouse_pressed(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        if button == MouseButton::Left && e.take() {
             (self.action.clone())(self)
         } else {
             vec![]
@@ -381,6 +387,7 @@ impl<C: GuiElemChildren + 'static> GuiElem for Button<C> {
     }
     fn key_focus(
         &mut self,
+        e: &mut EventInfo,
         _modifiers: speedy2d::window::ModifiersState,
         down: bool,
         key: Option<speedy2d::window::VirtualKeyCode>,
@@ -394,6 +401,7 @@ impl<C: GuiElemChildren + 'static> GuiElem for Button<C> {
                         | speedy2d::window::VirtualKeyCode::NumpadEnter,
                 )
             )
+            && e.take()
         {
             (self.action.clone())(self)
         } else {
diff --git a/musicdb-client/src/gui_library.rs b/musicdb-client/src/gui_library.rs
index 20bd9ff..cdab90f 100755
--- a/musicdb-client/src/gui_library.rs
+++ b/musicdb-client/src/gui_library.rs
@@ -27,7 +27,7 @@ use speedy2d::{
 
 use crate::{
     gui::{
-        Dragging, DrawInfo, GuiAction, GuiConfig, GuiElem, GuiElemCfg, GuiElemChildren,
+        Dragging, DrawInfo, EventInfo, GuiAction, GuiConfig, GuiElem, GuiElemCfg, GuiElemChildren,
         GuiElemWrapper,
     },
     gui_anim::AnimationController,
@@ -598,21 +598,22 @@ impl GuiElem for LibraryBrowser {
     }
     fn key_watch(
         &mut self,
+        e: &mut EventInfo,
         modifiers: speedy2d::window::ModifiersState,
         down: bool,
         key: Option<VirtualKeyCode>,
         _scan: speedy2d::window::KeyScancode,
     ) -> Vec<GuiAction> {
-        if down && crate::gui::hotkey_deselect_all(&modifiers, key) {
+        if down && crate::gui::hotkey_deselect_all(&modifiers, key) && e.take() {
             self.selected.clear();
         }
-        if down && crate::gui::hotkey_select_all(&modifiers, key) {
+        if down && crate::gui::hotkey_select_all(&modifiers, key) && e.take() {
             self.selected_add_all();
         }
-        if down && crate::gui::hotkey_select_albums(&modifiers, key) {
+        if down && crate::gui::hotkey_select_albums(&modifiers, key) && e.take() {
             self.selected_add_albums();
         }
-        if down && crate::gui::hotkey_select_songs(&modifiers, key) {
+        if down && crate::gui::hotkey_select_songs(&modifiers, key) && e.take() {
             self.selected_add_songs();
         }
         vec![]
@@ -953,8 +954,8 @@ impl GuiElem for ListArtist {
             info.mouse_pos.y - info.pos.top_left().y,
         );
     }
-    fn mouse_down(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        if button == MouseButton::Left {
+    fn mouse_down(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        if button == MouseButton::Left && e.take() {
             self.mouse = true;
             if self.sel {
                 vec![]
@@ -968,14 +969,16 @@ impl GuiElem for ListArtist {
             vec![]
         }
     }
-    fn mouse_up(&mut self, button: MouseButton) -> Vec<GuiAction> {
+    fn mouse_up(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
         if self.mouse && button == MouseButton::Left {
             self.mouse = false;
             self.config.redraw = true;
-            if !self.sel {
-                self.selected.insert_artist(self.id);
-            } else {
-                self.selected.remove_artist(&self.id);
+            if e.take() {
+                if !self.sel {
+                    self.selected.insert_artist(self.id);
+                } else {
+                    self.selected.remove_artist(&self.id);
+                }
             }
         }
         vec![]
@@ -1097,8 +1100,8 @@ impl GuiElem for ListAlbum {
             info.mouse_pos.y - info.pos.top_left().y,
         );
     }
-    fn mouse_down(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        if button == MouseButton::Left {
+    fn mouse_down(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        if button == MouseButton::Left && e.take() {
             self.mouse = true;
             if self.sel {
                 vec![]
@@ -1112,14 +1115,16 @@ impl GuiElem for ListAlbum {
             vec![]
         }
     }
-    fn mouse_up(&mut self, button: MouseButton) -> Vec<GuiAction> {
+    fn mouse_up(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
         if self.mouse && button == MouseButton::Left {
             self.mouse = false;
             self.config.redraw = true;
-            if !self.sel {
-                self.selected.insert_album(self.id);
-            } else {
-                self.selected.remove_album(&self.id);
+            if e.take() {
+                if !self.sel {
+                    self.selected.insert_album(self.id);
+                } else {
+                    self.selected.remove_album(&self.id);
+                }
             }
         }
         vec![]
@@ -1238,8 +1243,8 @@ impl GuiElem for ListSong {
             info.mouse_pos.y - info.pos.top_left().y,
         );
     }
-    fn mouse_down(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        if button == MouseButton::Left {
+    fn mouse_down(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        if button == MouseButton::Left && e.take() {
             self.mouse = true;
             if self.sel {
                 vec![]
@@ -1253,20 +1258,22 @@ impl GuiElem for ListSong {
             vec![]
         }
     }
-    fn mouse_up(&mut self, button: MouseButton) -> Vec<GuiAction> {
+    fn mouse_up(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
         if self.mouse && button == MouseButton::Left {
             self.mouse = false;
             self.config.redraw = true;
-            if !self.sel {
-                self.selected.insert_song(self.id);
-            } else {
-                self.selected.remove_song(&self.id);
+            if e.take() {
+                if !self.sel {
+                    self.selected.insert_song(self.id);
+                } else {
+                    self.selected.remove_song(&self.id);
+                }
             }
         }
         vec![]
     }
-    fn mouse_pressed(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        if button == MouseButton::Right {
+    fn mouse_pressed(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        if button == MouseButton::Right && e.take() {
             let id = self.id;
             vec![GuiAction::Build(Box::new(move |db| {
                 if let Some(me) = db.songs().get(&id) {
diff --git a/musicdb-client/src/gui_queue.rs b/musicdb-client/src/gui_queue.rs
index bf91983..d89e8f4 100755
--- a/musicdb-client/src/gui_queue.rs
+++ b/musicdb-client/src/gui_queue.rs
@@ -15,7 +15,7 @@ use speedy2d::{
 };
 
 use crate::{
-    gui::{Dragging, DrawInfo, GuiAction, GuiElem, GuiElemCfg},
+    gui::{Dragging, DrawInfo, EventInfo, GuiAction, GuiElem, GuiElemCfg},
     gui_base::{Panel, ScrollBox},
     gui_text::{self, AdvancedLabel, Label, TextField},
 };
@@ -399,7 +399,8 @@ impl GuiElem for QueueEmptySpaceDragHandler {
     fn elem_mut(&mut self) -> &mut dyn GuiElem {
         self
     }
-    fn dragged(&mut self, dragged: Dragging) -> Vec<GuiAction> {
+    fn dragged(&mut self, e: &mut EventInfo, dragged: Dragging) -> Vec<GuiAction> {
+        e.take();
         dragged_add_to_queue(
             dragged,
             (),
@@ -551,17 +552,17 @@ impl GuiElem for QueueSong {
     fn elem_mut(&mut self) -> &mut dyn GuiElem {
         self
     }
-    fn mouse_down(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        if button == MouseButton::Left {
+    fn mouse_down(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        if button == MouseButton::Left && e.take() {
             self.mouse = true;
             self.copy_on_mouse_down = self.copy;
         }
         vec![]
     }
-    fn mouse_up(&mut self, button: MouseButton) -> Vec<GuiAction> {
+    fn mouse_up(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
         if self.mouse && button == MouseButton::Left {
             self.mouse = false;
-            if !self.always_copy {
+            if e.take() && !self.always_copy {
                 vec![GuiAction::SendToServer(Command::QueueGoto(
                     self.path.clone(),
                 ))]
@@ -612,6 +613,7 @@ impl GuiElem for QueueSong {
     }
     fn key_watch(
         &mut self,
+        _e: &mut EventInfo,
         modifiers: ModifiersState,
         _down: bool,
         _key: Option<VirtualKeyCode>,
@@ -620,8 +622,9 @@ impl GuiElem for QueueSong {
         self.copy = self.always_copy || modifiers.ctrl();
         vec![]
     }
-    fn dragged(&mut self, dragged: Dragging) -> Vec<GuiAction> {
+    fn dragged(&mut self, e: &mut EventInfo, dragged: Dragging) -> Vec<GuiAction> {
         if !self.always_copy {
+            e.take();
             let insert_below = self.insert_below;
             dragged_add_to_queue(
                 dragged,
@@ -775,11 +778,11 @@ impl GuiElem for QueueFolder {
             self.copy_on_mouse_down,
         );
     }
-    fn mouse_down(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        if button == MouseButton::Left {
+    fn mouse_down(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        if button == MouseButton::Left && e.take() {
             self.mouse = true;
             self.copy_on_mouse_down = self.copy;
-        } else if button == MouseButton::Right {
+        } else if button == MouseButton::Right && e.take() {
             // return vec![GuiAction::ContextMenu(Some(vec![Box::new(
             //     Panel::with_background(GuiElemCfg::default(), (), Color::DARK_GRAY),
             // )]))];
@@ -791,10 +794,10 @@ impl GuiElem for QueueFolder {
         }
         vec![]
     }
-    fn mouse_up(&mut self, button: MouseButton) -> Vec<GuiAction> {
+    fn mouse_up(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
         if self.mouse && button == MouseButton::Left {
             self.mouse = false;
-            if !self.always_copy {
+            if e.take() && !self.always_copy {
                 vec![GuiAction::SendToServer(Command::QueueGoto(
                     self.path.clone(),
                 ))]
@@ -807,6 +810,7 @@ impl GuiElem for QueueFolder {
     }
     fn key_watch(
         &mut self,
+        _e: &mut EventInfo,
         modifiers: ModifiersState,
         _down: bool,
         _key: Option<VirtualKeyCode>,
@@ -815,8 +819,9 @@ impl GuiElem for QueueFolder {
         self.copy = modifiers.ctrl();
         vec![]
     }
-    fn dragged(&mut self, dragged: Dragging) -> Vec<GuiAction> {
+    fn dragged(&mut self, e: &mut EventInfo, dragged: Dragging) -> Vec<GuiAction> {
         if !self.always_copy {
+            e.take();
             if self.insert_into {
                 dragged_add_to_queue(
                     dragged,
@@ -893,7 +898,8 @@ impl GuiElem for QueueIndentEnd {
             );
         }
     }
-    fn dragged(&mut self, dragged: Dragging) -> Vec<GuiAction> {
+    fn dragged(&mut self, e: &mut EventInfo, dragged: Dragging) -> Vec<GuiAction> {
+        e.take();
         dragged_add_to_queue(
             dragged,
             self.path_insert.clone(),
@@ -987,8 +993,8 @@ impl GuiElem for QueueLoop {
     fn elem_mut(&mut self) -> &mut dyn GuiElem {
         self
     }
-    fn mouse_wheel(&mut self, diff: f32) -> Vec<GuiAction> {
-        if self.always_copy {
+    fn mouse_wheel(&mut self, e: &mut EventInfo, diff: f32) -> Vec<GuiAction> {
+        if self.always_copy && e.take() {
             if let QueueContent::Loop(total, _, _) = self.queue.content_mut() {
                 if diff > 0.0 {
                     *total += 1;
@@ -1020,17 +1026,17 @@ impl GuiElem for QueueLoop {
             self.copy_on_mouse_down,
         );
     }
-    fn mouse_down(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        if button == MouseButton::Left {
+    fn mouse_down(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        if button == MouseButton::Left && e.take() {
             self.mouse = true;
             self.copy_on_mouse_down = self.copy;
         }
         vec![]
     }
-    fn mouse_up(&mut self, button: MouseButton) -> Vec<GuiAction> {
+    fn mouse_up(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
         if self.mouse && button == MouseButton::Left {
             self.mouse = false;
-            if !self.always_copy {
+            if e.take() && !self.always_copy {
                 vec![GuiAction::SendToServer(Command::QueueGoto(
                     self.path.clone(),
                 ))]
@@ -1043,6 +1049,7 @@ impl GuiElem for QueueLoop {
     }
     fn key_watch(
         &mut self,
+        _e: &mut EventInfo,
         modifiers: ModifiersState,
         _down: bool,
         _key: Option<VirtualKeyCode>,
@@ -1051,8 +1058,9 @@ impl GuiElem for QueueLoop {
         self.copy = modifiers.ctrl();
         vec![]
     }
-    fn dragged(&mut self, dragged: Dragging) -> Vec<GuiAction> {
+    fn dragged(&mut self, e: &mut EventInfo, dragged: Dragging) -> Vec<GuiAction> {
         if !self.always_copy {
+            e.take();
             let mut p = self.path.clone();
             p.push(0);
             dragged_add_to_queue(
diff --git a/musicdb-client/src/gui_screen.rs b/musicdb-client/src/gui_screen.rs
index 85f1610..2c13c20 100755
--- a/musicdb-client/src/gui_screen.rs
+++ b/musicdb-client/src/gui_screen.rs
@@ -9,8 +9,8 @@ use uianimator::{default_animator_f64_quadratic::DefaultAnimatorF64Quadratic, An
 
 use crate::{
     gui::{
-        DrawInfo, GuiAction, GuiElem, GuiElemCfg, GuiElemChildren, KeyAction, KeyBinding,
-        SpecificGuiElem,
+        DrawInfo, EventInfo, GuiAction, GuiElem, GuiElemCfg, GuiElemChildren, KeyAction,
+        KeyBinding, SpecificGuiElem,
     },
     gui_base::{Button, Panel},
     gui_edit_song::EditorForSongs,
@@ -97,7 +97,7 @@ impl GuiScreen {
         scroll_sensitivity_pages: f64,
     ) -> Self {
         Self {
-            config: config.w_keyboard_watch().w_mouse().w_keyboard_focus(),
+            config: config.w_keyboard_watch().w_mouse(),
             c_notif_overlay,
             c_status_bar: StatusBar::new(GuiElemCfg::at(Rectangle::from_tuples(
                 (0.0, 0.9),
@@ -277,22 +277,48 @@ impl GuiElem for GuiScreen {
     }
     fn key_watch(
         &mut self,
+        e: &mut EventInfo,
         modifiers: speedy2d::window::ModifiersState,
         down: bool,
         key: Option<speedy2d::window::VirtualKeyCode>,
         _scan: speedy2d::window::KeyScancode,
     ) -> Vec<GuiAction> {
         if down {
+            // don't `e.take()` here (it might cause keys the user wanted to type to go missing + it would break the next if statement)
             self.not_idle();
         }
-        if self.hotkey.triggered(modifiers, down, key) {
+        if self.hotkey.triggered(modifiers, down, key) && e.take() {
             self.config.request_keyboard_focus = true;
             vec![GuiAction::ResetKeyboardFocus]
+        // } else if down && matches!(key, Some(VirtualKeyCode::Space)) && e.take() {
+        // MOVED TO CHAR_WATCH !!!
         } else {
             vec![]
         }
     }
-    fn mouse_down(&mut self, _button: speedy2d::window::MouseButton) -> Vec<GuiAction> {
+    fn char_watch(
+        &mut self,
+        e: &mut EventInfo,
+        modifiers: speedy2d::window::ModifiersState,
+        key: char,
+    ) -> Vec<GuiAction> {
+        if key == ' ' && !(modifiers.ctrl() || modifiers.alt() || modifiers.logo()) && e.take() {
+            vec![GuiAction::Build(Box::new(|db| {
+                vec![GuiAction::SendToServer(if db.playing {
+                    Command::Pause
+                } else {
+                    Command::Resume
+                })]
+            }))]
+        } else {
+            vec![]
+        }
+    }
+    fn mouse_down(
+        &mut self,
+        _e: &mut EventInfo,
+        _button: speedy2d::window::MouseButton,
+    ) -> Vec<GuiAction> {
         self.not_idle();
         vec![]
     }
@@ -300,7 +326,7 @@ impl GuiElem for GuiScreen {
         if self.config.init {
             info.actions.extend([
                 GuiAction::AddKeybind(
-                    Some(KeyBinding::ctrl(VirtualKeyCode::Q)),
+                    Some((KeyBinding::ctrl(VirtualKeyCode::Q), true)),
                     KeyAction {
                         category: "General".to_owned(),
                         title: "Quit".to_owned(),
@@ -311,7 +337,7 @@ impl GuiElem for GuiScreen {
                     Box::new(|_| {}),
                 ),
                 GuiAction::AddKeybind(
-                    Some(KeyBinding::ctrl(VirtualKeyCode::I)),
+                    Some((KeyBinding::ctrl(VirtualKeyCode::I), true)),
                     KeyAction {
                         category: "General".to_owned(),
                         title: "Idle".to_owned(),
@@ -322,7 +348,7 @@ impl GuiElem for GuiScreen {
                     Box::new(|_| {}),
                 ),
                 GuiAction::AddKeybind(
-                    Some(KeyBinding::ctrl(VirtualKeyCode::F)),
+                    Some((KeyBinding::ctrl(VirtualKeyCode::F), true)),
                     KeyAction {
                         category: "Library".to_owned(),
                         title: "Search songs".to_owned(),
@@ -414,28 +440,4 @@ impl GuiElem for GuiScreen {
             self.idle_timeout = self.c_settings.get_timeout_val();
         }
     }
-    fn key_focus(
-        &mut self,
-        _modifiers: speedy2d::window::ModifiersState,
-        down: bool,
-        key: Option<speedy2d::window::VirtualKeyCode>,
-        _scan: speedy2d::window::KeyScancode,
-    ) -> Vec<GuiAction> {
-        if down && matches!(key, Some(VirtualKeyCode::Space)) {
-            vec![GuiAction::Build(Box::new(|db| {
-                vec![GuiAction::SendToServer(if db.playing {
-                    Command::Pause
-                } else {
-                    Command::Resume
-                })]
-            }))]
-        } else if down && matches!(key, Some(VirtualKeyCode::F8)) {
-            vec![GuiAction::SendToServer(Command::ErrorInfo(
-                "".to_owned(),
-                "tEsT".to_owned(),
-            ))]
-        } else {
-            vec![]
-        }
-    }
 }
diff --git a/musicdb-client/src/gui_settings.rs b/musicdb-client/src/gui_settings.rs
index ceb4c0c..1998b40 100755
--- a/musicdb-client/src/gui_settings.rs
+++ b/musicdb-client/src/gui_settings.rs
@@ -11,8 +11,8 @@ use speedy2d::{
 
 use crate::{
     gui::{
-        DrawInfo, GuiAction, GuiElem, GuiElemCfg, GuiElemChildren, KeyAction, KeyActionId,
-        KeyBinding,
+        DrawInfo, EventInfo, GuiAction, GuiElem, GuiElemCfg, GuiElemChildren, KeyAction,
+        KeyActionId, KeyBinding,
     },
     gui_base::{Button, Panel, ScrollBox, Slider},
     gui_text::{AdvancedContent, AdvancedLabel, Content, Label},
@@ -139,8 +139,8 @@ impl KeybindInput {
     }
 }
 impl GuiElem for KeybindInput {
-    fn mouse_pressed(&mut self, button: MouseButton) -> Vec<GuiAction> {
-        if let MouseButton::Left = button {
+    fn mouse_pressed(&mut self, e: &mut EventInfo, button: MouseButton) -> Vec<GuiAction> {
+        if MouseButton::Left == button && e.take() {
             if !self.has_keyboard_focus {
                 self.changing = true;
                 self.config.request_keyboard_focus = true;
@@ -154,6 +154,7 @@ impl GuiElem for KeybindInput {
     }
     fn key_focus(
         &mut self,
+        e: &mut EventInfo,
         modifiers: ModifiersState,
         down: bool,
         key: Option<VirtualKeyCode>,
@@ -171,13 +172,14 @@ impl GuiElem for KeybindInput {
                         | VirtualKeyCode::RAlt
                         | VirtualKeyCode::LWin
                         | VirtualKeyCode::RWin
-                ) {
+                ) && e.take()
+                {
                     self.changing = false;
                     let bind = KeyBinding::new(&modifiers, key);
                     self.keybinds_should_be_updated
                         .store(true, std::sync::atomic::Ordering::Relaxed);
                     vec![
-                        GuiAction::SetKeybind(self.id, Some(bind)),
+                        GuiAction::SetKeybind(self.id, Some((bind, true))),
                         GuiAction::ResetKeyboardFocus,
                     ]
                 } else {
diff --git a/musicdb-client/src/gui_text.rs b/musicdb-client/src/gui_text.rs
index e916c09..1b2a5b0 100755
--- a/musicdb-client/src/gui_text.rs
+++ b/musicdb-client/src/gui_text.rs
@@ -10,7 +10,7 @@ use speedy2d::{
     window::{ModifiersState, MouseButton},
 };
 
-use crate::gui::{GuiAction, GuiElem, GuiElemCfg, GuiServerImage};
+use crate::gui::{EventInfo, GuiAction, GuiElem, GuiElemCfg, GuiServerImage};
 
 /*
 
@@ -224,12 +224,24 @@ impl GuiElem for TextField {
         g.draw_line(info.pos.top_left(), info.pos.bottom_left(), t, c);
         g.draw_line(info.pos.top_right(), info.pos.bottom_right(), t, c);
     }
-    fn mouse_pressed(&mut self, _button: MouseButton) -> Vec<GuiAction> {
-        self.config.request_keyboard_focus = true;
-        vec![GuiAction::ResetKeyboardFocus]
+    fn mouse_pressed(&mut self, e: &mut EventInfo, _button: MouseButton) -> Vec<GuiAction> {
+        if e.take() {
+            self.config.request_keyboard_focus = true;
+            vec![GuiAction::ResetKeyboardFocus]
+        } else {
+            vec![]
+        }
     }
-    fn char_focus(&mut self, modifiers: ModifiersState, key: char) -> Vec<GuiAction> {
-        if !(modifiers.ctrl() || modifiers.alt() || modifiers.logo()) && !key.is_control() {
+    fn char_focus(
+        &mut self,
+        e: &mut EventInfo,
+        modifiers: ModifiersState,
+        key: char,
+    ) -> Vec<GuiAction> {
+        if !(modifiers.ctrl() || modifiers.alt() || modifiers.logo())
+            && !key.is_control()
+            && e.take()
+        {
             let content = &mut self.c_input.content;
             let was_empty = content.get_text().is_empty();
             content.text().push(key);
@@ -249,6 +261,7 @@ impl GuiElem for TextField {
     }
     fn key_focus(
         &mut self,
+        e: &mut EventInfo,
         modifiers: ModifiersState,
         down: bool,
         key: Option<speedy2d::window::VirtualKeyCode>,
@@ -257,6 +270,7 @@ impl GuiElem for TextField {
         if down
             && !(modifiers.alt() || modifiers.logo())
             && key == Some(speedy2d::window::VirtualKeyCode::Backspace)
+            && e.take()
         {
             let content = &mut self.c_input.content;
             if !content.get_text().is_empty() {
diff --git a/musicdb-client/src/main.rs b/musicdb-client/src/main.rs
index ba7e878..fb963d1 100755
--- a/musicdb-client/src/main.rs
+++ b/musicdb-client/src/main.rs
@@ -264,24 +264,35 @@ fn main() {
         }
         #[cfg(feature = "mers")]
         Mode::RunMers { path } => {
-            let mut src = mers_lib::prelude_compile::Source::new_from_file(path).unwrap();
+            let mut src =
+                musicdb_mers::mers_lib::prelude_compile::Source::new_from_file(path).unwrap();
             let srca = Arc::new(src.clone());
             let con = Mutex::new(con);
             let (mut i1, mut i2, mut i3) = musicdb_mers::add(
-                mers_lib::prelude_compile::Config::new().bundle_std(),
+                musicdb_mers::mers_lib::prelude_compile::Config::new().bundle_std(),
                 &database,
                 &Arc::new(move |cmd: Command| cmd.to_bytes(&mut *con.lock().unwrap()).unwrap()),
                 &mers_after_db_updated_action,
             )
             .infos();
-            let program = mers_lib::prelude_compile::parse(&mut src, &srca)
-                .unwrap()
-                .compile(&mut i1, mers_lib::prelude_compile::CompInfo::default())
-                .unwrap();
+            let program = match musicdb_mers::mers_lib::prelude_compile::parse(&mut src, &srca) {
+                Ok(p) => p,
+                Err(e) => {
+                    eprintln!("{}", e.display_term());
+                    std::process::exit(60);
+                }
+            };
+            let program = match program.compile(&mut i1, Default::default()) {
+                Ok(p) => p,
+                Err(e) => {
+                    eprintln!("{}", e.display_term());
+                    std::process::exit(60);
+                }
+            };
             match program.check(&mut i3, None) {
                 Ok(_) => {}
                 Err(e) => {
-                    eprintln!("{e}");
+                    eprintln!("{}", e.display_term());
                     std::process::exit(60);
                 }
             };
@@ -293,7 +304,9 @@ fn main() {
                     break;
                 }
             }
-            program.run(&mut i2);
+            if let Err(e) = program.run(&mut i2) {
+                eprintln!("{}", e.display_term());
+            }
         }
     }
 }
diff --git a/musicdb-client/src/merscfg.rs b/musicdb-client/src/merscfg.rs
index 66da22d..74d914b 100644
--- a/musicdb-client/src/merscfg.rs
+++ b/musicdb-client/src/merscfg.rs
@@ -8,12 +8,11 @@ use std::{
     time::Duration,
 };
 
-use mers_lib::{
-    data::{Data, MersType, Type},
-    errors::CheckError,
-    prelude_compile::CompInfo,
-};
 use musicdb_lib::{data::database::Database, server::Command};
+use musicdb_mers::mers_lib::{
+    data::{Data, Type},
+    errors::CheckError,
+};
 use speedy2d::{color::Color, dimen::Vec2, shape::Rectangle, window::UserEventSender};
 
 use crate::{
@@ -24,17 +23,17 @@ use crate::{
     textcfg::TextBuilder,
 };
 
-pub struct OptFunc(pub Option<mers_lib::data::function::Function>);
+pub struct OptFunc(pub Option<musicdb_mers::mers_lib::data::function::Function>);
 impl OptFunc {
     pub fn none() -> Self {
         Self(None)
     }
-    pub fn some(func: mers_lib::data::function::Function) -> Self {
+    pub fn some(func: musicdb_mers::mers_lib::data::function::Function) -> Self {
         Self(Some(func))
     }
     fn run(&self) {
         if let Some(func) = &self.0 {
-            func.run(Data::empty_tuple());
+            func.run_immut(Data::empty_tuple());
         }
     }
 }
@@ -71,7 +70,6 @@ pub struct MersCfg {
     pub func_library_updated: OptFunc,
     pub func_queue_updated: OptFunc,
     // - - globals that aren't functions - -
-    pub var_is_playing: Arc<RwLock<Data>>,
     pub var_is_idle: Arc<RwLock<Data>>,
     pub var_window_size_in_pixels: Arc<RwLock<Data>>,
     pub var_idle_screen_cover_aspect_ratio: Arc<RwLock<Data>>,
@@ -104,16 +102,17 @@ impl MersCfg {
             func_library_updated: OptFunc::none(),
             func_queue_updated: OptFunc::none(),
 
-            var_is_playing: Arc::new(RwLock::new(Data::new(mers_lib::data::bool::Bool(false)))),
-            var_is_idle: Arc::new(RwLock::new(Data::new(mers_lib::data::bool::Bool(false)))),
+            var_is_idle: Arc::new(RwLock::new(Data::new(
+                musicdb_mers::mers_lib::data::bool::Bool(false),
+            ))),
             var_window_size_in_pixels: Arc::new(RwLock::new(Data::new(
-                mers_lib::data::tuple::Tuple(vec![
-                    Data::new(mers_lib::data::int::Int(0)),
-                    Data::new(mers_lib::data::int::Int(0)),
+                musicdb_mers::mers_lib::data::tuple::Tuple(vec![
+                    Data::new(musicdb_mers::mers_lib::data::int::Int(0)),
+                    Data::new(musicdb_mers::mers_lib::data::int::Int(0)),
                 ]),
             ))),
             var_idle_screen_cover_aspect_ratio: Arc::new(RwLock::new(Data::new(
-                mers_lib::data::float::Float(0.0),
+                musicdb_mers::mers_lib::data::float::Float(0.0),
             ))),
 
             channel_gui_actions: std::sync::mpsc::channel(),
@@ -133,36 +132,31 @@ impl MersCfg {
     }
     fn custom_globals(
         &self,
-        cfg: mers_lib::prelude_extend_config::Config,
+        cfg: musicdb_mers::mers_lib::prelude_extend_config::Config,
         db: &Arc<Mutex<Database>>,
         event_sender: Arc<UserEventSender<GuiEvent>>,
         notif_sender: Sender<
             Box<dyn FnOnce(&NotifOverlay) -> (Box<dyn GuiElem>, NotifInfo) + Send>,
         >,
         after_db_cmd: &Arc<Mutex<Option<Box<dyn FnMut(Command) + Send + Sync + 'static>>>>,
-    ) -> mers_lib::prelude_extend_config::Config {
+    ) -> musicdb_mers::mers_lib::prelude_extend_config::Config {
         let cmd_es = event_sender.clone();
         let cmd_ga = self.channel_gui_actions.0.clone();
         musicdb_mers::add(cfg, db, &Arc::new(move |cmd| {
             cmd_ga.send(cmd).unwrap();
             cmd_es.send_event(GuiEvent::RefreshMers).unwrap();
         }), after_db_cmd)
-            .add_var_arc(
-            "is_playing".to_owned(),
-            Arc::clone(&self.var_is_playing),
-            self.var_is_playing.read().unwrap().get().as_type(),
-        )
-        .add_var_arc(
+        .add_var_from_arc(
             "is_idle".to_owned(),
             Arc::clone(&self.var_is_idle),
             self.var_is_idle.read().unwrap().get().as_type(),
         )
-        .add_var_arc(
+        .add_var_from_arc(
             "window_size_in_pixels".to_owned(),
             Arc::clone(&self.var_window_size_in_pixels),
             self.var_window_size_in_pixels.read().unwrap().get().as_type(),
         )
-        .add_var_arc(
+        .add_var_from_arc(
             "idle_screen_cover_aspect_ratio".to_owned(),
             Arc::clone(&self.var_idle_screen_cover_aspect_ratio),
             self.var_idle_screen_cover_aspect_ratio.read().unwrap().get().as_type(),
@@ -170,155 +164,135 @@ impl MersCfg {
         .add_var("playback_resume".to_owned(),{
             let es = event_sender.clone();
             let v = Arc::clone(&self.updated_playing_status);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
                     if a.is_zero_tuple() {
                         Ok(Type::empty_tuple())
                     } else {
                         Err(format!("Can't call `playback_resume` with argument of type `{a}` (must be `()`).").into())
                     }
-                }),
-                run: Arc::new(move |_, _| {
+                },
+                move |_, _| {
                     v.store(1, std::sync::atomic::Ordering::Relaxed);
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    Data::empty_tuple()
-                }),
-                inner_statements: None,
-            })
+                    Ok(Data::empty_tuple())
+                },
+            )
         })
         .add_var("playback_pause".to_owned(),{
             let es = event_sender.clone();
             let v = Arc::clone(&self.updated_playing_status);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
                     if a.is_zero_tuple() {
                         Ok(Type::empty_tuple())
                     } else {
                         Err(format!("Can't call `playback_pause` with argument of type `{a}` (must be `()`).").into())
                     }
-                }),
-                run: Arc::new(move |_, _| {
+                },
+                move |_, _| {
                     v.store(2, std::sync::atomic::Ordering::Relaxed);
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    Data::empty_tuple()
-                }),
-                inner_statements: None,
-            })
+                    Ok(Data::empty_tuple())
+                },
+            )
         })
         .add_var("playback_stop".to_owned(),{
             let es = event_sender.clone();
             let v = Arc::clone(&self.updated_playing_status);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
                     if a.is_zero_tuple() {
                         Ok(Type::empty_tuple())
                     } else {
                         Err(format!("Can't call `playback_stop` with argument of type `{a}` (must be `()`).").into())
                     }
-                }),
-                run: Arc::new(move |_, _| {
+                },
+                move |_, _| {
                     v.store(3, std::sync::atomic::Ordering::Relaxed);
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    Data::empty_tuple()
-                }),
-                inner_statements: None,
-            })
+                    Ok(Data::empty_tuple())
+                },
+            )
         })
         .add_var("idle_start".to_owned(),{
             let es = event_sender.clone();
             let v = Arc::clone(&self.updated_idle_status);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
                     if a.is_zero_tuple() {
                         Ok(Type::empty_tuple())
                     } else {
                         Err(format!("Can't call `idle_start` with argument of type `{a}` (must be `()`).").into())
                     }
-                }),
-                run: Arc::new(move |_, _| {
+                },
+                move |_, _| {
                     v.store(1, std::sync::atomic::Ordering::Relaxed);
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    Data::empty_tuple()
-                }),
-                inner_statements: None,
-            })
+                    Ok(Data::empty_tuple())
+                },
+            )
         })
         .add_var("idle_stop".to_owned(),{
             let es = event_sender.clone();
             let v = Arc::clone(&self.updated_idle_status);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
                     if a.is_zero_tuple() {
                         Ok(Type::empty_tuple())
                     } else {
                         Err(format!("Can't call `idle_stop` with argument of type `{a}` (must be `()`).").into())
                     }
-                }),
-                run: Arc::new(move |_, _| {
+                },
+                move |_, _| {
                     v.store(2, std::sync::atomic::Ordering::Relaxed);
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    Data::empty_tuple()
-                }),
-                inner_statements: None,
-            })
+                    Ok(Data::empty_tuple())
+                },
+            )
         })
         .add_var("idle_prevent".to_owned(),{
             let es = event_sender.clone();
             let v = Arc::clone(&self.updated_idle_status);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a | {
                     if a.is_zero_tuple() {
                         Ok(Type::empty_tuple())
                     } else {
                         Err(format!("Can't call `idle_prevent` with argument of type `{a}` (must be `()`).").into())
                     }
-                }),
-                run: Arc::new(move |_, _| {
+                },
+                move |_, _| {
                     v.store(3, std::sync::atomic::Ordering::Relaxed);
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    Data::empty_tuple()
-                }),
-                inner_statements: None,
-            })
+                    Ok(Data::empty_tuple())
+                },
+            )
         })
         .add_var("send_notification".to_owned(),{
             let es = event_sender.clone();
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
-                    if a.is_included_in(&mers_lib::data::tuple::TupleT(vec![
-                        mers_lib::data::Type::new(mers_lib::data::string::StringT),
-                        mers_lib::data::Type::new(mers_lib::data::string::StringT),
-                        mers_lib::data::Type::newm(vec![
-                            Arc::new(mers_lib::data::int::IntT),
-                            Arc::new(mers_lib::data::float::FloatT)
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
+                    if a.is_included_in_single(&musicdb_mers::mers_lib::data::tuple::TupleT(vec![
+                        musicdb_mers::mers_lib::data::Type::new(musicdb_mers::mers_lib::data::string::StringT),
+                        musicdb_mers::mers_lib::data::Type::new(musicdb_mers::mers_lib::data::string::StringT),
+                        musicdb_mers::mers_lib::data::Type::newm(vec![
+                            Arc::new(musicdb_mers::mers_lib::data::int::IntT),
+                            Arc::new(musicdb_mers::mers_lib::data::float::FloatT)
                         ]),
                     ])) {
                         Ok(Type::empty_tuple())
                     } else {
                         Err(format!("Can't call `send_notification` with argument of type `{a}` (must be `String`).").into())
                     }
-                }),
-                run: Arc::new(move |a, _| {
+                },
+                move |a, _| {
                     let a = a.get();
-                    let t = &a.as_any().downcast_ref::<mers_lib::data::tuple::Tuple>().unwrap().0;
-                    let title = t[0].get().as_any().downcast_ref::<mers_lib::data::string::String>().unwrap().0.clone();
-                    let text = t[1].get().as_any().downcast_ref::<mers_lib::data::string::String>().unwrap().0.clone();
+                    let t = &a.as_any().downcast_ref::<musicdb_mers::mers_lib::data::tuple::Tuple>().unwrap().0;
+                    let title = t[0].get().as_any().downcast_ref::<musicdb_mers::mers_lib::data::string::String>().unwrap().0.clone();
+                    let text = t[1].get().as_any().downcast_ref::<musicdb_mers::mers_lib::data::string::String>().unwrap().0.clone();
                     let t = t[2].get();
-                    let duration = t.as_any().downcast_ref::<mers_lib::data::int::Int>().map(|s| Duration::from_secs(s.0.max(0) as _)).unwrap_or_else(|| Duration::from_secs_f64(t.as_any().downcast_ref::<mers_lib::data::float::Float>().unwrap().0));
+                    let duration = t.as_any().downcast_ref::<musicdb_mers::mers_lib::data::int::Int>().map(|s| Duration::from_secs(s.0.max(0) as _)).unwrap_or_else(|| Duration::from_secs_f64(t.as_any().downcast_ref::<musicdb_mers::mers_lib::data::float::Float>().unwrap().0));
                     notif_sender
                         .send(Box::new(move |_| {
                             (
@@ -353,77 +327,70 @@ impl MersCfg {
                         }))
                         .unwrap();
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    Data::empty_tuple()
-                }),
-                inner_statements: None,
-            })
+                    Ok(Data::empty_tuple())
+                },
+            )
         })
         .add_var("set_idle_screen_cover_pos".to_owned(),{
             let es = event_sender.clone();
             let update = Arc::clone(&self.updated_idle_screen_cover_pos);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
-                    if a.is_included_in(&mers_lib::data::Type::newm(vec![
-                        Arc::new(mers_lib::data::tuple::TupleT(vec![])),
-                        Arc::new(mers_lib::data::tuple::TupleT(vec![
-                            mers_lib::data::Type::new(mers_lib::data::float::FloatT),
-                            mers_lib::data::Type::new(mers_lib::data::float::FloatT),
-                            mers_lib::data::Type::new(mers_lib::data::float::FloatT),
-                            mers_lib::data::Type::new(mers_lib::data::float::FloatT),
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
+                    if a.is_included_in(&musicdb_mers::mers_lib::data::Type::newm(vec![
+                        Arc::new(musicdb_mers::mers_lib::data::tuple::TupleT(vec![])),
+                        Arc::new(musicdb_mers::mers_lib::data::tuple::TupleT(vec![
+                            musicdb_mers::mers_lib::data::Type::new(musicdb_mers::mers_lib::data::float::FloatT),
+                            musicdb_mers::mers_lib::data::Type::new(musicdb_mers::mers_lib::data::float::FloatT),
+                            musicdb_mers::mers_lib::data::Type::new(musicdb_mers::mers_lib::data::float::FloatT),
+                            musicdb_mers::mers_lib::data::Type::new(musicdb_mers::mers_lib::data::float::FloatT),
                         ]))
                     ])) {
                         Ok(Type::empty_tuple())
                     } else {
                         Err(format!("Can't call `set_idle_screen_cover_pos` with argument of type `{a}` (must be `()` or `(Float, Float, Float, Float)`).").into())
                     }
-                }),
-                run: Arc::new(move |a, _| {
+                },
+                move |a, _| {
                     let a = a.get();
-                    let mut vals = a.as_any().downcast_ref::<mers_lib::data::tuple::Tuple>().unwrap().0.iter().map(|v| v.get().as_any().downcast_ref::<mers_lib::data::float::Float>().unwrap().0);
+                    let mut vals = a.as_any().downcast_ref::<musicdb_mers::mers_lib::data::tuple::Tuple>().unwrap().0.iter().map(|v| v.get().as_any().downcast_ref::<musicdb_mers::mers_lib::data::float::Float>().unwrap().0);
                     update.update(
                     if vals.len() >= 4 {
                         Some(Rectangle::from_tuples((vals.next().unwrap() as _, vals.next().unwrap() as _), (vals.next().unwrap() as _, vals.next().unwrap() as _)))
                     } else { None });
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    Data::empty_tuple()
-                }),
-                inner_statements: None,
-            })
+                    Ok(Data::empty_tuple())
+                },
+            )
         }).add_var("set_idle_screen_artist_image_pos".to_owned(),{
             let es = event_sender.clone();
             let update = Arc::clone(&self.updated_idle_screen_artist_image_pos);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
-                    if a.is_included_in(&mers_lib::data::Type::newm(vec![
-                        Arc::new(mers_lib::data::tuple::TupleT(vec![])),
-                        Arc::new(mers_lib::data::tuple::TupleT(vec![
-                            mers_lib::data::Type::new(mers_lib::data::float::FloatT),
-                            mers_lib::data::Type::new(mers_lib::data::float::FloatT),
-                            mers_lib::data::Type::new(mers_lib::data::float::FloatT),
-                            mers_lib::data::Type::new(mers_lib::data::float::FloatT),
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
+                    if a.is_included_in(&musicdb_mers::mers_lib::data::Type::newm(vec![
+                        Arc::new(musicdb_mers::mers_lib::data::tuple::TupleT(vec![])),
+                        Arc::new(musicdb_mers::mers_lib::data::tuple::TupleT(vec![
+                            musicdb_mers::mers_lib::data::Type::new(musicdb_mers::mers_lib::data::float::FloatT),
+                            musicdb_mers::mers_lib::data::Type::new(musicdb_mers::mers_lib::data::float::FloatT),
+                            musicdb_mers::mers_lib::data::Type::new(musicdb_mers::mers_lib::data::float::FloatT),
+                            musicdb_mers::mers_lib::data::Type::new(musicdb_mers::mers_lib::data::float::FloatT),
                         ]))
                     ])) {
                         Ok(Type::empty_tuple())
                     } else {
                         Err(format!("Can't call `set_idle_screen_artist_image_pos` with argument of type `{a}` (must be `()` or `(Float, Float, Float, Float)`).").into())
                     }
-                }),
-                run: Arc::new(move |a, _| {
+                },
+                move |a, _| {
                     let a = a.get();
-                    let mut vals = a.as_any().downcast_ref::<mers_lib::data::tuple::Tuple>().unwrap().0.iter().map(|v| v.get().as_any().downcast_ref::<mers_lib::data::float::Float>().unwrap().0);
+                    let mut vals = a.as_any().downcast_ref::<musicdb_mers::mers_lib::data::tuple::Tuple>().unwrap().0.iter().map(|v| v.get().as_any().downcast_ref::<musicdb_mers::mers_lib::data::float::Float>().unwrap().0);
                     update.update(
                     if vals.len() >= 4 {
                         Some(Rectangle::from_tuples((vals.next().unwrap() as _, vals.next().unwrap() as _), (vals.next().unwrap() as _, vals.next().unwrap() as _)))
                     } else { None });
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    Data::empty_tuple()
-                }),
-                inner_statements: None,
-            })
+                    Ok(Data::empty_tuple())
+                },
+            )
         })
         .add_var("set_idle_screen_top_text_pos".to_owned(), gen_set_pos_func("set_idle_screen_top_text_pos", Arc::clone(&event_sender), Arc::clone(&self.updated_idle_screen_top_text_pos)))
         .add_var("set_idle_screen_side_text_1_pos".to_owned(), gen_set_pos_func("set_idle_screen_side_text_1_pos", Arc::clone(&event_sender), Arc::clone(&self.updated_idle_screen_side_text_1_pos)))
@@ -433,153 +400,142 @@ impl MersCfg {
         .add_var("set_statusbar_text_format".to_owned(),{
             let es = event_sender.clone();
             let update = Arc::clone(&self.updated_statusbar_text_format);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
-                    if a.is_included_in(&mers_lib::data::string::StringT) {
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
+                    if a.is_included_in_single(&musicdb_mers::mers_lib::data::string::StringT) {
                         Ok(Type::newm(vec![
-                            Arc::new(mers_lib::data::tuple::TupleT(vec![])),
-                            Arc::new(mers_lib::data::string::StringT),
+                            Arc::new(musicdb_mers::mers_lib::data::tuple::TupleT(vec![])),
+                            Arc::new(musicdb_mers::mers_lib::data::string::StringT),
                         ]))
                     } else {
                         Err(format!("Can't call `set_statusbar_text_format` with argument of type `{a}` (must be `String`).").into())
                     }
-                }),
-                run: Arc::new(move |a, _| {
+                },
+                move |a, _| {
                     let a = a.get();
-                    let o = match a.as_any().downcast_ref::<mers_lib::data::string::String>().unwrap().0.parse() {
+                    let o = match a.as_any().downcast_ref::<musicdb_mers::mers_lib::data::string::String>().unwrap().0.parse() {
                         Ok(v) => {
                             update.update(v);
                             Data::empty_tuple()
                         }
-                        Err(e) => mers_lib::data::Data::new(mers_lib::data::string::String(e.to_string())),
+                        Err(e) => musicdb_mers::mers_lib::data::Data::new(musicdb_mers::mers_lib::data::string::String(e.to_string())),
                     };
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    o
-                }),
-                inner_statements: None,
-            })
+                    Ok(o)
+                },
+            )
         })
         .add_var("set_idle_screen_top_text_format".to_owned(),{
             let es = event_sender.clone();
             let update = Arc::clone(&self.updated_idle_screen_top_text_format);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
-                    if a.is_included_in(&mers_lib::data::string::StringT) {
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
+                    if a.is_included_in_single(&musicdb_mers::mers_lib::data::string::StringT) {
                         Ok(Type::newm(vec![
-                            Arc::new(mers_lib::data::tuple::TupleT(vec![])),
-                            Arc::new(mers_lib::data::string::StringT),
+                            Arc::new(musicdb_mers::mers_lib::data::tuple::TupleT(vec![])),
+                            Arc::new(musicdb_mers::mers_lib::data::string::StringT),
                         ]))
                     } else {
                         Err(format!("Can't call `set_idle_screen_top_text_format` with argument of type `{a}` (must be `String`).").into())
                     }
-                }),
-                run: Arc::new(move |a, _| {
+                },
+                move |a, _| {
                     let a = a.get();
-                    let o = match a.as_any().downcast_ref::<mers_lib::data::string::String>().unwrap().0.parse() {
+                    let o = match a.as_any().downcast_ref::<musicdb_mers::mers_lib::data::string::String>().unwrap().0.parse() {
                         Ok(v) => {
                             update.update(v);
                             Data::empty_tuple()
                         }
-                        Err(e) => mers_lib::data::Data::new(mers_lib::data::string::String(e.to_string())),
+                        Err(e) => musicdb_mers::mers_lib::data::Data::new(musicdb_mers::mers_lib::data::string::String(e.to_string())),
                     };
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    o
-                }),
-                inner_statements: None,
-            })
+                    Ok(o)
+                },
+            )
         }).add_var("set_idle_screen_side_text_1_format".to_owned(),{
             let es = event_sender.clone();
             let update = Arc::clone(&self.updated_idle_screen_side_text_1_format);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
-                    if a.is_included_in(&mers_lib::data::string::StringT) {
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
+                    if a.is_included_in_single(&musicdb_mers::mers_lib::data::string::StringT) {
                         Ok(Type::newm(vec![
-                            Arc::new(mers_lib::data::tuple::TupleT(vec![])),
-                            Arc::new(mers_lib::data::string::StringT),
+                            Arc::new(musicdb_mers::mers_lib::data::tuple::TupleT(vec![])),
+                            Arc::new(musicdb_mers::mers_lib::data::string::StringT),
                         ]))
                     } else {
                         Err(format!("Can't call `set_idle_screen_side_text_1_format` with argument of type `{a}` (must be `String`).").into())
                     }
-                }),
-                run: Arc::new(move |a, _| {
+                },
+                move |a, _| {
                     let a = a.get();
-                    let o = match a.as_any().downcast_ref::<mers_lib::data::string::String>().unwrap().0.parse() {
+                    let o = match a.as_any().downcast_ref::<musicdb_mers::mers_lib::data::string::String>().unwrap().0.parse() {
                         Ok(v) => {
                             update.update(v);
                             Data::empty_tuple()
                         }
-                        Err(e) => mers_lib::data::Data::new(mers_lib::data::string::String(e.to_string())),
+                        Err(e) => musicdb_mers::mers_lib::data::Data::new(musicdb_mers::mers_lib::data::string::String(e.to_string())),
                     };
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    o
-                }),
-                inner_statements: None,
-            })
+                    Ok(o)
+                },
+            )
         }).add_var("set_idle_screen_side_text_2_format".to_owned(),{
             let es = event_sender.clone();
             let update = Arc::clone(&self.updated_idle_screen_side_text_2_format);
-            Data::new(mers_lib::data::function::Function {
-                info: Arc::new(mers_lib::info::Info::neverused()),
-                info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-                out: Arc::new(|a, _| {
-                    if a.is_included_in(&mers_lib::data::string::StringT) {
+            musicdb_mers::mers_lib::data::function::Function::new_generic(
+                |a| {
+                    if a.is_included_in_single(&musicdb_mers::mers_lib::data::string::StringT) {
                         Ok(Type::newm(vec![
-                            Arc::new(mers_lib::data::tuple::TupleT(vec![])),
-                            Arc::new(mers_lib::data::string::StringT),
+                            Arc::new(musicdb_mers::mers_lib::data::tuple::TupleT(vec![])),
+                            Arc::new(musicdb_mers::mers_lib::data::string::StringT),
                         ]))
                     } else {
                         Err(format!("Can't call `set_idle_screen_side_text_2_format` with argument of type `{a}` (must be `String`).").into())
                     }
-                }),
-                run: Arc::new(move |a, _| {
+                },
+                move |a, _| {
                     let a = a.get();
-                    let o = match a.as_any().downcast_ref::<mers_lib::data::string::String>().unwrap().0.parse() {
+                    let o = match a.as_any().downcast_ref::<musicdb_mers::mers_lib::data::string::String>().unwrap().0.parse() {
                         Ok(v) => {
                             update.update(v);
                             Data::empty_tuple()
                         }
-                        Err(e) => mers_lib::data::Data::new(mers_lib::data::string::String(e.to_string())),
+                        Err(e) => musicdb_mers::mers_lib::data::Data::new(musicdb_mers::mers_lib::data::string::String(e.to_string())),
                     };
                     es.send_event(GuiEvent::Refresh).unwrap();
-                    o
-                }),
-                inner_statements: None,
-            })
+                    Ok(o)
+                },
+            )
         })
-        // .add_type("Song".to_owned(), Ok(Arc::new(mers_lib::data::object::ObjectT(vec![
-        //         ("id".to_owned(), Type::new(mers_lib::data::int::IntT)),
-        //         ("title".to_owned(), Type::new(mers_lib::data::string::StringT)),
-        //         ("album".to_owned(), Type::new(mers_lib::data::string::StringT)),
-        //         ("artist".to_owned(), Type::new(mers_lib::data::string::StringT)),
+        // .add_type("Song".to_owned(), Ok(Arc::new(musicdb_mers::mers_lib::data::object::ObjectT(vec![
+        //         ("id".to_owned(), Type::new(musicdb_mers::mers_lib::data::int::IntT)),
+        //         ("title".to_owned(), Type::new(musicdb_mers::mers_lib::data::string::StringT)),
+        //         ("album".to_owned(), Type::new(musicdb_mers::mers_lib::data::string::StringT)),
+        //         ("artist".to_owned(), Type::new(musicdb_mers::mers_lib::data::string::StringT)),
         //     ]))))
     }
 
     pub fn run(gui_cfg: &mut GuiConfig, gui: &mut Gui, run: impl FnOnce(&Self) -> &OptFunc) {
-        {
-            let mut db = gui_cfg.merscfg.database.lock().unwrap();
-            let db = &mut db;
-            // prepare vars
-            *gui_cfg.merscfg.var_is_playing.write().unwrap() =
-                mers_lib::data::Data::new(mers_lib::data::bool::Bool(db.playing));
-        }
+        // prepare vars
         *gui_cfg.merscfg.var_window_size_in_pixels.write().unwrap() =
-            mers_lib::data::Data::new(mers_lib::data::tuple::Tuple(vec![
-                mers_lib::data::Data::new(mers_lib::data::int::Int(gui.size.x as _)),
-                mers_lib::data::Data::new(mers_lib::data::int::Int(gui.size.y as _)),
-            ]));
+            musicdb_mers::mers_lib::data::Data::new(musicdb_mers::mers_lib::data::tuple::Tuple(
+                vec![
+                    musicdb_mers::mers_lib::data::Data::new(
+                        musicdb_mers::mers_lib::data::int::Int(gui.size.x as _),
+                    ),
+                    musicdb_mers::mers_lib::data::Data::new(
+                        musicdb_mers::mers_lib::data::int::Int(gui.size.y as _),
+                    ),
+                ],
+            ));
         *gui_cfg
             .merscfg
             .var_idle_screen_cover_aspect_ratio
             .write()
-            .unwrap() = mers_lib::data::Data::new(mers_lib::data::float::Float(
-            gui.gui.c_idle_display.cover_aspect_ratio.value as _,
-        ));
+            .unwrap() =
+            musicdb_mers::mers_lib::data::Data::new(musicdb_mers::mers_lib::data::float::Float(
+                gui.gui.c_idle_display.cover_aspect_ratio.value as _,
+            ));
 
         // run
         run(&gui_cfg.merscfg).run();
@@ -707,12 +663,14 @@ impl MersCfg {
         >,
         after_db_cmd: &Arc<Mutex<Option<Box<dyn FnMut(Command) + Send + Sync + 'static>>>>,
     ) -> std::io::Result<Result<Result<(), (String, Option<CheckError>)>, CheckError>> {
-        let src = mers_lib::prelude_compile::Source::new_from_file(self.source_file.clone())?;
+        let src = musicdb_mers::mers_lib::prelude_compile::Source::new_from_file(
+            self.source_file.clone(),
+        )?;
         Ok(self.load2(src, event_sender, notif_sender, after_db_cmd))
     }
     fn load2(
         &mut self,
-        mut src: mers_lib::prelude_compile::Source,
+        mut src: musicdb_mers::mers_lib::prelude_compile::Source,
         event_sender: Arc<UserEventSender<GuiEvent>>,
         notif_sender: Sender<
             Box<dyn FnOnce(&NotifOverlay) -> (Box<dyn GuiElem>, NotifInfo) + Send>,
@@ -722,24 +680,27 @@ impl MersCfg {
         let srca = Arc::new(src.clone());
         let (mut i1, mut i2, mut i3) = self
             .custom_globals(
-                mers_lib::prelude_extend_config::Config::new().bundle_std(),
+                musicdb_mers::mers_lib::prelude_extend_config::Config::new().bundle_std(),
                 &self.database,
                 event_sender,
                 notif_sender,
                 after_db_cmd,
             )
             .infos();
-        let compiled = mers_lib::prelude_compile::parse(&mut src, &srca)?
-            .compile(&mut i1, CompInfo::default())?;
+        let compiled = musicdb_mers::mers_lib::prelude_compile::parse(&mut src, &srca)?
+            .compile(&mut i1, Default::default())?;
         let _ = compiled.check(&mut i3, None)?;
-        let out = compiled.run(&mut i2);
+        let out = compiled.run(&mut i2)?;
         Ok(self.load3(out))
     }
-    fn load3(&mut self, out: mers_lib::data::Data) -> Result<(), (String, Option<CheckError>)> {
+    fn load3(
+        &mut self,
+        out: musicdb_mers::mers_lib::data::Data,
+    ) -> Result<(), (String, Option<CheckError>)> {
         if let Some(obj) = out
             .get()
             .as_any()
-            .downcast_ref::<mers_lib::data::object::Object>()
+            .downcast_ref::<musicdb_mers::mers_lib::data::object::Object>()
         {
             for (name, val) in obj.0.iter() {
                 let name = name.as_str();
@@ -759,7 +720,7 @@ impl MersCfg {
                 }
             }
         } else {
-            return Err((format!("mers config file must return an object!"), None));
+            return Err((String::from("mers config file must return an object! (optional) fields of the object: `before_draw`, `library_updated`, `queue_updated`."), None));
         }
         Ok(())
     }
@@ -767,12 +728,12 @@ impl MersCfg {
 
 fn check_handler(
     name: &str,
-    val: &mers_lib::data::Data,
-) -> Result<mers_lib::data::function::Function, (String, Option<CheckError>)> {
+    val: &musicdb_mers::mers_lib::data::Data,
+) -> Result<musicdb_mers::mers_lib::data::function::Function, (String, Option<CheckError>)> {
     if let Some(func) = val
         .get()
         .as_any()
-        .downcast_ref::<mers_lib::data::function::Function>()
+        .downcast_ref::<musicdb_mers::mers_lib::data::function::Function>()
     {
         match func.check(&Type::empty_tuple()) {
             Ok(_) => Ok(func.clone()),
@@ -787,36 +748,42 @@ fn gen_set_pos_func(
     name: &'static str,
     es: Arc<UserEventSender<GuiEvent>>,
     update: Arc<Updatable<Rectangle>>,
-) -> Data {
-    Data::new(mers_lib::data::function::Function {
-        info: Arc::new(mers_lib::info::Info::neverused()),
-        info_check: Arc::new(Mutex::new(mers_lib::info::Info::neverused())),
-        out: Arc::new(move |a, _| {
-            if a.is_included_in(&mers_lib::data::Type::newm(vec![Arc::new(
-                mers_lib::data::tuple::TupleT(vec![
-                    mers_lib::data::Type::new(mers_lib::data::float::FloatT),
-                    mers_lib::data::Type::new(mers_lib::data::float::FloatT),
-                    mers_lib::data::Type::new(mers_lib::data::float::FloatT),
-                    mers_lib::data::Type::new(mers_lib::data::float::FloatT),
+) -> musicdb_mers::mers_lib::data::function::Function {
+    musicdb_mers::mers_lib::data::function::Function::new_generic(
+        move |a| {
+            if a.is_included_in(&musicdb_mers::mers_lib::data::Type::newm(vec![Arc::new(
+                musicdb_mers::mers_lib::data::tuple::TupleT(vec![
+                    musicdb_mers::mers_lib::data::Type::new(
+                        musicdb_mers::mers_lib::data::float::FloatT,
+                    ),
+                    musicdb_mers::mers_lib::data::Type::new(
+                        musicdb_mers::mers_lib::data::float::FloatT,
+                    ),
+                    musicdb_mers::mers_lib::data::Type::new(
+                        musicdb_mers::mers_lib::data::float::FloatT,
+                    ),
+                    musicdb_mers::mers_lib::data::Type::new(
+                        musicdb_mers::mers_lib::data::float::FloatT,
+                    ),
                 ]),
             )])) {
                 Ok(Type::empty_tuple())
             } else {
                 Err(format!("Can't call `{name}` with argument of type `{a}` (must be `(Float, Float, Float, Float)`).").into())
             }
-        }),
-        run: Arc::new(move |a, _| {
+        },
+        move |a, _| {
             let a = a.get();
             let mut vals = a
                 .as_any()
-                .downcast_ref::<mers_lib::data::tuple::Tuple>()
+                .downcast_ref::<musicdb_mers::mers_lib::data::tuple::Tuple>()
                 .unwrap()
                 .0
                 .iter()
                 .map(|v| {
                     v.get()
                         .as_any()
-                        .downcast_ref::<mers_lib::data::float::Float>()
+                        .downcast_ref::<musicdb_mers::mers_lib::data::float::Float>()
                         .unwrap()
                         .0
                 });
@@ -825,10 +792,9 @@ fn gen_set_pos_func(
                 (vals.next().unwrap() as _, vals.next().unwrap() as _),
             ));
             es.send_event(GuiEvent::Refresh).unwrap();
-            Data::empty_tuple()
-        }),
-        inner_statements: None,
-    })
+            Ok(Data::empty_tuple())
+        },
+    )
 }
 
 pub struct Updatable<T> {
diff --git a/musicdb-mers/Cargo.toml b/musicdb-mers/Cargo.toml
index 5b12227..f14ab45 100644
--- a/musicdb-mers/Cargo.toml
+++ b/musicdb-mers/Cargo.toml
@@ -6,5 +6,5 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+mers_lib = { version = "0.9.1", features = ["ecolor-term"] }
 musicdb-lib = { version = "0.1.0", path = "../musicdb-lib" }
-mers_lib = "0.3.4"
diff --git a/musicdb-mers/src/lib.rs b/musicdb-mers/src/lib.rs
index 85ab0f8..d4a810e 100644
--- a/musicdb-mers/src/lib.rs
+++ b/musicdb-mers/src/lib.rs
@@ -3,9 +3,10 @@ use std::{
     sync::{Arc, Mutex, RwLock},
 };
 
+pub use mers_lib;
+
 use mers_lib::{
     data::{self, function::Function, Data, MersData, MersType, Type},
-    info::Info,
     prelude_extend_config::Config,
 };
 use musicdb_lib::{
@@ -25,17 +26,6 @@ pub fn add(
     cmd: &Arc<impl Fn(Command) + Sync + Send + 'static>,
     after_db_cmd: &Arc<Mutex<Option<Box<dyn FnMut(Command) + Send + Sync + 'static>>>>,
 ) -> Config {
-    macro_rules! func {
-        ($out:expr, $run:expr) => {
-            Data::new(data::function::Function {
-                info: Arc::new(Info::neverused()),
-                info_check: Arc::new(Mutex::new(Info::neverused())),
-                out: Arc::new($out),
-                run: Arc::new($run),
-                inner_statements: None,
-            })
-        };
-    }
     /// handle commands received from server (for handler functions)
     /// `T` can be used to return generated data to avoid calculating something twice if one event may call multiple handlers.
     fn handle<T>(
@@ -50,7 +40,7 @@ pub fn add(
             .downcast_ref::<Function>()
         {
             let (data, t) = gen();
-            Some((t, func.run(data)))
+            Some((t, func.run_immut(data).ok()?))
         } else {
             None
         }
@@ -143,7 +133,7 @@ pub fn add(
     // MusicDb type
     cfg = cfg
         .with_list()
-        .add_type(MusicDbIdT.to_string(), Ok(Arc::new(MusicDbIdT)));
+        .add_type(MusicDbIdT.to_string(), Ok(Arc::new(Type::new(MusicDbIdT))));
     // handler setters
     for (name, handler, in_type) in [
         ("resume", handler_resume, Type::empty_tuple()),
@@ -166,15 +156,13 @@ pub fn add(
     ] {
         cfg = cfg.add_var(
             format!("handle_event_{name}"),
-            func!(
-                move |a, _| {
+            Function::new_generic(
+                move |a| {
                     if a.types.iter().all(|a| {
                         Type::newm(vec![Arc::clone(a)]).is_zero_tuple()
                             || a.as_any()
                                 .downcast_ref::<data::function::FunctionT>()
-                                .is_some_and(|a| {
-                                    (a.0)(&in_type).is_ok_and(|opt| opt.is_zero_tuple())
-                                })
+                                .is_some_and(|a| a.o(&in_type).is_ok_and(|opt| opt.is_zero_tuple()))
                     }) {
                         Ok(Type::empty_tuple())
                     } else {
@@ -183,17 +171,17 @@ pub fn add(
                 },
                 move |a, _| {
                     *handler.write().unwrap() = a;
-                    Data::empty_tuple()
-                }
+                    Ok(Data::empty_tuple())
+                },
             ),
         );
     }
     // actions
     cfg.add_var(
         "send_server_notification".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&data::string::StringT) {
+        Function::new_generic(
+            |a| {
+                if a.is_included_in_single(&data::string::StringT) {
                     Ok(Type::empty_tuple())
                 } else {
                     Err(format!("Function argument must be `String`.").into())
@@ -211,15 +199,15 @@ pub fn add(
                             .0
                             .clone(),
                     ));
-                    Data::empty_tuple()
+                    Ok(Data::empty_tuple())
                 }
-            }
+            },
         ),
     )
     .add_var(
         "resume".to_owned(),
-        func!(
-            |a, _| {
+        Function::new_generic(
+            |a| {
                 if a.is_included_in(&Type::empty_tuple()) {
                     Ok(Type::empty_tuple())
                 } else {
@@ -230,15 +218,15 @@ pub fn add(
                 let cmd = Arc::clone(cmd);
                 move |_, _| {
                     cmd(Command::Resume);
-                    Data::empty_tuple()
+                    Ok(Data::empty_tuple())
                 }
-            }
+            },
         ),
     )
     .add_var(
         "pause".to_owned(),
-        func!(
-            |a, _| {
+        Function::new_generic(
+            |a| {
                 if a.is_included_in(&Type::empty_tuple()) {
                     Ok(Type::empty_tuple())
                 } else {
@@ -249,15 +237,15 @@ pub fn add(
                 let cmd = Arc::clone(cmd);
                 move |_, _| {
                     cmd(Command::Pause);
-                    Data::empty_tuple()
+                    Ok(Data::empty_tuple())
                 }
-            }
+            },
         ),
     )
     .add_var(
-        "stop_playback".to_owned(),
-        func!(
-            |a, _| {
+        "stop".to_owned(),
+        Function::new_generic(
+            |a| {
                 if a.is_included_in(&Type::empty_tuple()) {
                     Ok(Type::empty_tuple())
                 } else {
@@ -268,15 +256,15 @@ pub fn add(
                 let cmd = Arc::clone(cmd);
                 move |_, _| {
                     cmd(Command::Stop);
-                    Data::empty_tuple()
+                    Ok(Data::empty_tuple())
                 }
-            }
+            },
         ),
     )
     .add_var(
         "next_song".to_owned(),
-        func!(
-            |a, _| {
+        Function::new_generic(
+            |a| {
                 if a.is_included_in(&Type::empty_tuple()) {
                     Ok(Type::empty_tuple())
                 } else {
@@ -287,31 +275,31 @@ pub fn add(
                 let cmd = Arc::clone(cmd);
                 move |_, _| {
                     cmd(Command::NextSong);
-                    Data::empty_tuple()
+                    Ok(Data::empty_tuple())
                 }
-            }
+            },
         ),
     )
     .add_var(
         "get_playing".to_owned(),
-        func!(
-            |a, _| {
+        Function::new_generic(
+            |a| {
                 if a.is_included_in(&Type::empty_tuple()) {
-                    Ok(Type::new(data::bool::BoolT))
+                    Ok(data::bool::bool_type())
                 } else {
                     Err(format!("Function argument must be `()`.").into())
                 }
             },
             {
                 let db = Arc::clone(db);
-                move |_, _| Data::new(data::bool::Bool(db.lock().unwrap().playing))
-            }
+                move |_, _| Ok(Data::new(data::bool::Bool(db.lock().unwrap().playing)))
+            },
         ),
     )
     .add_var(
         "queue_get_current_song".to_owned(),
-        func!(
-            |a, _| {
+        Function::new_generic(
+            |a| {
                 if a.is_included_in(&Type::empty_tuple()) {
                     Ok(Type::newm(vec![
                         Arc::new(MusicDbIdT),
@@ -323,17 +311,19 @@ pub fn add(
             },
             {
                 let db = Arc::clone(db);
-                move |_, _| match db.lock().unwrap().queue.get_current_song() {
-                    Some(id) => Data::new(MusicDbId(*id)),
-                    None => Data::empty_tuple(),
+                move |_, _| {
+                    Ok(match db.lock().unwrap().queue.get_current_song() {
+                        Some(id) => Data::new(MusicDbId(*id)),
+                        None => Data::empty_tuple(),
+                    })
                 }
-            }
+            },
         ),
     )
     .add_var(
         "queue_get_next_song".to_owned(),
-        func!(
-            |a, _| {
+        Function::new_generic(
+            |a| {
                 if a.is_included_in(&Type::empty_tuple()) {
                     Ok(Type::newm(vec![
                         Arc::new(MusicDbIdT),
@@ -345,21 +335,23 @@ pub fn add(
             },
             {
                 let db = Arc::clone(db);
-                move |_, _| match db.lock().unwrap().queue.get_next_song() {
-                    Some(id) => Data::new(MusicDbId(*id)),
-                    None => Data::empty_tuple(),
+                move |_, _| {
+                    Ok(match db.lock().unwrap().queue.get_next_song() {
+                        Some(id) => Data::new(MusicDbId(*id)),
+                        None => Data::empty_tuple(),
+                    })
                 }
-            }
+            },
         ),
     )
     .add_var(
         "queue_get_elem".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&mers_lib::program::configs::with_list::ListT(Type::new(
-                    data::int::IntT,
-                ))) {
-                    Ok(gen_queue_elem_type())
+        Function::new_generic(
+            |a| {
+                if a.is_included_in_single(&mers_lib::program::configs::with_list::ListT(
+                    Type::new(data::int::IntT),
+                )) {
+                    Ok(gen_queue_elem_type_or_empty_tuple())
                 } else {
                     Err(format!("Function argument must be `List<Int>`.").into())
                 }
@@ -368,22 +360,24 @@ pub fn add(
                 let db = Arc::clone(db);
                 move |a, _| {
                     let a = int_list_to_usize_vec(&a);
-                    if let Some(elem) = db.lock().unwrap().queue.get_item_at_index(&a, 0) {
-                        gen_queue_elem(elem)
-                    } else {
-                        Data::empty_tuple()
-                    }
+                    Ok(
+                        if let Some(elem) = db.lock().unwrap().queue.get_item_at_index(&a, 0) {
+                            gen_queue_elem(elem)
+                        } else {
+                            Data::empty_tuple()
+                        },
+                    )
                 }
-            }
+            },
         ),
     )
     .add_var(
         "queue_goto".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&mers_lib::program::configs::with_list::ListT(Type::new(
-                    data::int::IntT,
-                ))) {
+        Function::new_generic(
+            |a| {
+                if a.is_included_in_single(&mers_lib::program::configs::with_list::ListT(
+                    Type::new(data::int::IntT),
+                )) {
                     Ok(Type::empty_tuple())
                 } else {
                     Err(format!("Function argument must be `List<Int>`.").into())
@@ -393,15 +387,15 @@ pub fn add(
                 let cmd = Arc::clone(cmd);
                 move |a, _| {
                     cmd(Command::QueueGoto(int_list_to_usize_vec(&a)));
-                    Data::empty_tuple()
+                    Ok(Data::empty_tuple())
                 }
-            }
+            },
         ),
     )
     .add_var(
         "queue_clear".to_owned(),
-        func!(
-            |a, _| {
+        Function::new_generic(
+            |a| {
                 if a.is_included_in(&Type::empty_tuple()) {
                     Ok(Type::empty_tuple())
                 } else {
@@ -415,133 +409,134 @@ pub fn add(
                         vec![],
                         QueueContent::Folder(QueueFolder::default()).into(),
                     ));
-                    Data::empty_tuple()
-                }
-            }
-        ),
-    )
-    .add_var(
-        "queue_add_song".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&data::tuple::TupleT(vec![
-                    Type::new(mers_lib::program::configs::with_list::ListT(Type::new(
-                        data::int::IntT,
-                    ))),
-                    Type::new(MusicDbIdT),
-                ])) {
-                    Ok(Type::empty_tuple())
-                } else {
-                    Err(format!("Function argument must be `(List<Int>, MusicDbId)`.").into())
+                    Ok(Data::empty_tuple())
                 }
             },
-            {
-                let cmd = Arc::clone(cmd);
-                move |a, _| {
-                    let a = a.get();
-                    let a = &a.as_any().downcast_ref::<data::tuple::Tuple>().unwrap().0;
-                    let path = int_list_to_usize_vec(&a[0]);
-                    let song_id = a[1].get().as_any().downcast_ref::<MusicDbId>().unwrap().0;
-                    cmd(Command::QueueAdd(
-                        path,
-                        vec![QueueContent::Song(song_id).into()],
-                    ));
-                    Data::empty_tuple()
-                }
-            }
-        ),
-    )
-    .add_var(
-        "queue_add_loop".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&data::tuple::TupleT(vec![
-                    Type::new(mers_lib::program::configs::with_list::ListT(Type::new(
-                        data::int::IntT,
-                    ))),
-                    Type::new(data::int::IntT),
-                ])) {
-                    Ok(Type::empty_tuple())
-                } else {
-                    Err(format!("Function argument must be `(List<Int>, Int)`.").into())
-                }
-            },
-            {
-                let cmd = Arc::clone(cmd);
-                move |a, _| {
-                    let a = a.get();
-                    let a = &a.as_any().downcast_ref::<data::tuple::Tuple>().unwrap().0;
-                    let path = int_list_to_usize_vec(&a[0]);
-                    let repeat_count = a[1]
-                        .get()
-                        .as_any()
-                        .downcast_ref::<data::int::Int>()
-                        .unwrap()
-                        .0;
-                    cmd(Command::QueueAdd(
-                        path,
-                        vec![QueueContent::Loop(
-                            repeat_count.max(0) as _,
-                            0,
-                            Box::new(QueueContent::Folder(QueueFolder::default()).into()),
-                        )
-                        .into()],
-                    ));
-                    Data::empty_tuple()
-                }
-            }
-        ),
-    )
-    .add_var(
-        "queue_add_folder".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&data::tuple::TupleT(vec![
-                    Type::new(mers_lib::program::configs::with_list::ListT(Type::new(
-                        data::int::IntT,
-                    ))),
-                    Type::new(data::string::StringT),
-                ])) {
-                    Ok(Type::empty_tuple())
-                } else {
-                    Err(format!("Function argument must be `(List<Int>, String)`.").into())
-                }
-            },
-            {
-                let cmd = Arc::clone(cmd);
-                move |a, _| {
-                    let a = a.get();
-                    let a = &a.as_any().downcast_ref::<data::tuple::Tuple>().unwrap().0;
-                    let path = int_list_to_usize_vec(&a[0]);
-                    let name = a[1]
-                        .get()
-                        .as_any()
-                        .downcast_ref::<data::string::String>()
-                        .unwrap()
-                        .0
-                        .clone();
-                    cmd(Command::QueueAdd(
-                        path,
-                        vec![QueueContent::Folder(QueueFolder {
-                            index: 0,
-                            content: vec![],
-                            name,
-                            order: None,
-                        })
-                        .into()],
-                    ));
-                    Data::empty_tuple()
-                }
-            }
         ),
     )
+    // TODO: `queue_add`, which takes any queue element as defined in `gen_queue_elem_type`
+    // .add_var(
+    //     "queue_add_song".to_owned(),
+    //     Function::new_generic(
+    //         |a| {
+    //             if a.is_included_in_single(&data::tuple::TupleT(vec![
+    //                 Type::new(mers_lib::program::configs::with_list::ListT(Type::new(
+    //                     data::int::IntT,
+    //                 ))),
+    //                 Type::new(MusicDbIdT),
+    //             ])) {
+    //                 Ok(Type::empty_tuple())
+    //             } else {
+    //                 Err(format!("Function argument must be `(List<Int>, MusicDbId)`.").into())
+    //             }
+    //         },
+    //         {
+    //             let cmd = Arc::clone(cmd);
+    //             move |a, _| {
+    //                 let a = a.get();
+    //                 let a = &a.as_any().downcast_ref::<data::tuple::Tuple>().unwrap().0;
+    //                 let path = int_list_to_usize_vec(&a[0]);
+    //                 let song_id = a[1].get().as_any().downcast_ref::<MusicDbId>().unwrap().0;
+    //                 cmd(Command::QueueAdd(
+    //                     path,
+    //                     vec![QueueContent::Song(song_id).into()],
+    //                 ));
+    //                 Ok(Data::empty_tuple())
+    //             }
+    //         },
+    //     ),
+    // )
+    // .add_var(
+    //     "queue_add_loop".to_owned(),
+    //     Function::new_generic(
+    //         |a| {
+    //             if a.is_included_in_single(&data::tuple::TupleT(vec![
+    //                 Type::new(mers_lib::program::configs::with_list::ListT(Type::new(
+    //                     data::int::IntT,
+    //                 ))),
+    //                 Type::new(data::int::IntT),
+    //             ])) {
+    //                 Ok(Type::empty_tuple())
+    //             } else {
+    //                 Err(format!("Function argument must be `(List<Int>, Int)`.").into())
+    //             }
+    //         },
+    //         {
+    //             let cmd = Arc::clone(cmd);
+    //             move |a, _| {
+    //                 let a = a.get();
+    //                 let a = &a.as_any().downcast_ref::<data::tuple::Tuple>().unwrap().0;
+    //                 let path = int_list_to_usize_vec(&a[0]);
+    //                 let repeat_count = a[1]
+    //                     .get()
+    //                     .as_any()
+    //                     .downcast_ref::<data::int::Int>()
+    //                     .unwrap()
+    //                     .0;
+    //                 cmd(Command::QueueAdd(
+    //                     path,
+    //                     vec![QueueContent::Loop(
+    //                         repeat_count.max(0) as _,
+    //                         0,
+    //                         Box::new(QueueContent::Folder(QueueFolder::default()).into()),
+    //                     )
+    //                     .into()],
+    //                 ));
+    //                 Ok(Data::empty_tuple())
+    //             }
+    //         },
+    //     ),
+    // )
+    // .add_var(
+    //     "queue_add_folder".to_owned(),
+    //     Function::new_generic(
+    //         |a| {
+    //             if a.is_included_in_single(&data::tuple::TupleT(vec![
+    //                 Type::new(mers_lib::program::configs::with_list::ListT(Type::new(
+    //                     data::int::IntT,
+    //                 ))),
+    //                 Type::new(data::string::StringT),
+    //             ])) {
+    //                 Ok(Type::empty_tuple())
+    //             } else {
+    //                 Err(format!("Function argument must be `(List<Int>, String)`.").into())
+    //             }
+    //         },
+    //         {
+    //             let cmd = Arc::clone(cmd);
+    //             move |a, _| {
+    //                 let a = a.get();
+    //                 let a = &a.as_any().downcast_ref::<data::tuple::Tuple>().unwrap().0;
+    //                 let path = int_list_to_usize_vec(&a[0]);
+    //                 let name = a[1]
+    //                     .get()
+    //                     .as_any()
+    //                     .downcast_ref::<data::string::String>()
+    //                     .unwrap()
+    //                     .0
+    //                     .clone();
+    //                 cmd(Command::QueueAdd(
+    //                     path,
+    //                     vec![QueueContent::Folder(QueueFolder {
+    //                         index: 0,
+    //                         content: vec![],
+    //                         name,
+    //                         order: None,
+    //                     })
+    //                     .into()],
+    //                 ));
+    //                 Ok(Data::empty_tuple())
+    //             }
+    //         },
+    //     ),
+    // )
     .add_var(
         "all_songs".to_owned(),
-        func!(
-            |a, _| {
+        Function::new_generic(
+            |a| {
                 if a.is_zero_tuple() {
                     Ok(Type::new(mers_lib::program::configs::with_list::ListT(
-                        gen_song_type(),
+                        Type::new(gen_song_type()),
                     )))
                 } else {
                     Err(format!("Function argument must be `()`.").into())
@@ -550,23 +545,23 @@ pub fn add(
             {
                 let db = Arc::clone(db);
                 move |_, _| {
-                    Data::new(mers_lib::program::configs::with_list::List(
+                    Ok(Data::new(mers_lib::program::configs::with_list::List(
                         db.lock()
                             .unwrap()
                             .songs()
                             .values()
                             .map(|s| Arc::new(RwLock::new(gen_song(s))))
                             .collect(),
-                    ))
+                    )))
                 }
-            }
+            },
         ),
     )
     .add_var(
         "get_song".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&MusicDbIdT) {
+        Function::new_generic(
+            |a| {
+                if a.is_included_in_single(&MusicDbIdT) {
                     Ok(Type::newm(vec![
                         Arc::new(gen_song_type()),
                         Arc::new(data::tuple::TupleT(vec![])),
@@ -579,19 +574,19 @@ pub fn add(
                 let db = Arc::clone(db);
                 move |a, _| {
                     let id = a.get().as_any().downcast_ref::<MusicDbId>().unwrap().0;
-                    match db.lock().unwrap().get_song(&id) {
+                    Ok(match db.lock().unwrap().get_song(&id) {
                         Some(song) => gen_song(song),
                         None => Data::empty_tuple(),
-                    }
+                    })
                 }
-            }
+            },
         ),
     )
     .add_var(
         "get_album".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&MusicDbIdT) {
+        Function::new_generic(
+            |a| {
+                if a.is_included_in_single(&MusicDbIdT) {
                     Ok(Type::newm(vec![
                         Arc::new(gen_album_type()),
                         Arc::new(data::tuple::TupleT(vec![])),
@@ -604,19 +599,19 @@ pub fn add(
                 let db = Arc::clone(db);
                 move |a, _| {
                     let id = a.get().as_any().downcast_ref::<MusicDbId>().unwrap().0;
-                    match db.lock().unwrap().albums().get(&id) {
+                    Ok(match db.lock().unwrap().albums().get(&id) {
                         Some(album) => gen_album(album),
                         None => Data::empty_tuple(),
-                    }
+                    })
                 }
-            }
+            },
         ),
     )
     .add_var(
         "get_artist".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&MusicDbIdT) {
+        Function::new_generic(
+            |a| {
+                if a.is_included_in_single(&MusicDbIdT) {
                     Ok(Type::newm(vec![
                         Arc::new(gen_artist_type()),
                         Arc::new(data::tuple::TupleT(vec![])),
@@ -629,19 +624,19 @@ pub fn add(
                 let db = Arc::clone(db);
                 move |a, _| {
                     let id = a.get().as_any().downcast_ref::<MusicDbId>().unwrap().0;
-                    match db.lock().unwrap().artists().get(&id) {
+                    Ok(match db.lock().unwrap().artists().get(&id) {
                         Some(artist) => gen_artist(artist),
                         None => Data::empty_tuple(),
-                    }
+                    })
                 }
-            }
+            },
         ),
     )
     .add_var(
         "get_song_tags".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&MusicDbIdT) {
+        Function::new_generic(
+            |a| {
+                if a.is_included_in_single(&MusicDbIdT) {
                     Ok(Type::newm(vec![
                         Arc::new(mers_lib::program::configs::with_list::ListT(Type::new(
                             data::string::StringT,
@@ -656,7 +651,7 @@ pub fn add(
                 let db = Arc::clone(db);
                 move |a, _| {
                     let id = a.get().as_any().downcast_ref::<MusicDbId>().unwrap().0;
-                    match db.lock().unwrap().get_song(&id) {
+                    Ok(match db.lock().unwrap().get_song(&id) {
                         Some(song) => Data::new(mers_lib::program::configs::with_list::List(
                             song.general
                                 .tags
@@ -669,16 +664,16 @@ pub fn add(
                                 .collect(),
                         )),
                         None => Data::empty_tuple(),
-                    }
+                    })
                 }
-            }
+            },
         ),
     )
     .add_var(
         "get_album_tags".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&MusicDbIdT) {
+        Function::new_generic(
+            |a| {
+                if a.is_included_in_single(&MusicDbIdT) {
                     Ok(Type::newm(vec![
                         Arc::new(mers_lib::program::configs::with_list::ListT(Type::new(
                             data::string::StringT,
@@ -693,7 +688,7 @@ pub fn add(
                 let db = Arc::clone(db);
                 move |a, _| {
                     let id = a.get().as_any().downcast_ref::<MusicDbId>().unwrap().0;
-                    match db.lock().unwrap().albums().get(&id) {
+                    Ok(match db.lock().unwrap().albums().get(&id) {
                         Some(album) => Data::new(mers_lib::program::configs::with_list::List(
                             album
                                 .general
@@ -707,16 +702,16 @@ pub fn add(
                                 .collect(),
                         )),
                         None => Data::empty_tuple(),
-                    }
+                    })
                 }
-            }
+            },
         ),
     )
     .add_var(
         "get_artist_tags".to_owned(),
-        func!(
-            |a, _| {
-                if a.is_included_in(&MusicDbIdT) {
+        Function::new_generic(
+            |a| {
+                if a.is_included_in_single(&MusicDbIdT) {
                     Ok(Type::newm(vec![
                         Arc::new(mers_lib::program::configs::with_list::ListT(Type::new(
                             data::string::StringT,
@@ -731,7 +726,7 @@ pub fn add(
                 let db = Arc::clone(db);
                 move |a, _| {
                     let id = a.get().as_any().downcast_ref::<MusicDbId>().unwrap().0;
-                    match db.lock().unwrap().artists().get(&id) {
+                    Ok(match db.lock().unwrap().artists().get(&id) {
                         Some(artist) => Data::new(mers_lib::program::configs::with_list::List(
                             artist
                                 .general
@@ -745,15 +740,15 @@ pub fn add(
                                 .collect(),
                         )),
                         None => Data::empty_tuple(),
-                    }
+                    })
                 }
-            }
+            },
         ),
     )
 }
 
-fn gen_song_type() -> Type {
-    Type::new(data::object::ObjectT(vec![
+fn gen_song_type() -> data::object::ObjectT {
+    data::object::ObjectT(vec![
         ("id".to_owned(), Type::new(MusicDbIdT)),
         ("title".to_owned(), Type::new(data::string::StringT)),
         (
@@ -771,7 +766,7 @@ fn gen_song_type() -> Type {
                 Arc::new(data::tuple::TupleT(vec![])),
             ]),
         ),
-    ]))
+    ])
 }
 fn gen_song(song: &Song) -> Data {
     Data::new(data::object::Object(vec![
@@ -799,8 +794,8 @@ fn gen_song(song: &Song) -> Data {
         ),
     ]))
 }
-fn gen_album_type() -> Type {
-    Type::new(data::object::ObjectT(vec![
+fn gen_album_type() -> data::object::ObjectT {
+    data::object::ObjectT(vec![
         ("id".to_owned(), Type::new(MusicDbIdT)),
         ("name".to_owned(), Type::new(data::string::StringT)),
         ("artist".to_owned(), Type::new(MusicDbIdT)),
@@ -817,7 +812,7 @@ fn gen_album_type() -> Type {
                 MusicDbIdT,
             ))),
         ),
-    ]))
+    ])
 }
 fn gen_album(album: &Album) -> Data {
     Data::new(data::object::Object(vec![
@@ -847,8 +842,8 @@ fn gen_album(album: &Album) -> Data {
         ),
     ]))
 }
-fn gen_artist_type() -> Type {
-    Type::new(data::object::ObjectT(vec![
+fn gen_artist_type() -> data::object::ObjectT {
+    data::object::ObjectT(vec![
         ("id".to_owned(), Type::new(MusicDbIdT)),
         ("name".to_owned(), Type::new(data::string::StringT)),
         (
@@ -870,7 +865,7 @@ fn gen_artist_type() -> Type {
                 MusicDbIdT,
             ))),
         ),
-    ]))
+    ])
 }
 fn gen_artist(artist: &Artist) -> Data {
     Data::new(data::object::Object(vec![
@@ -910,15 +905,15 @@ fn gen_artist(artist: &Artist) -> Data {
     ]))
 }
 
-fn gen_queue_elem_type() -> Type {
+fn gen_queue_elem_type_or_empty_tuple() -> Type {
     Type::newm(vec![
         Arc::new(data::tuple::TupleT(vec![])),
         Arc::new(data::object::ObjectT(vec![
-            ("enabled".to_owned(), Type::new(data::bool::BoolT)),
+            ("enabled".to_owned(), data::bool::bool_type()),
             ("song".to_owned(), Type::new(MusicDbIdT)),
         ])),
         Arc::new(data::object::ObjectT(vec![
-            ("enabled".to_owned(), Type::new(data::bool::BoolT)),
+            ("enabled".to_owned(), data::bool::bool_type()),
             (
                 "loop".to_owned(),
                 Type::new(data::object::ObjectT(vec![
@@ -928,11 +923,11 @@ fn gen_queue_elem_type() -> Type {
             ),
         ])),
         Arc::new(data::object::ObjectT(vec![
-            ("enabled".to_owned(), Type::new(data::bool::BoolT)),
+            ("enabled".to_owned(), data::bool::bool_type()),
             ("random".to_owned(), Type::empty_tuple()),
         ])),
         Arc::new(data::object::ObjectT(vec![
-            ("enabled".to_owned(), Type::new(data::bool::BoolT)),
+            ("enabled".to_owned(), data::bool::bool_type()),
             (
                 "folder".to_owned(),
                 Type::new(data::object::ObjectT(vec![
@@ -943,7 +938,7 @@ fn gen_queue_elem_type() -> Type {
             ),
         ])),
         Arc::new(data::object::ObjectT(vec![
-            ("enabled".to_owned(), Type::new(data::bool::BoolT)),
+            ("enabled".to_owned(), data::bool::bool_type()),
             ("shuffle".to_owned(), Type::empty_tuple()),
         ])),
     ])
@@ -1038,7 +1033,7 @@ impl MersType for MusicDbIdT {
     fn is_same_type_as(&self, other: &dyn MersType) -> bool {
         other.as_any().is::<Self>()
     }
-    fn is_included_in_single(&self, target: &dyn MersType) -> bool {
+    fn is_included_in(&self, target: &dyn MersType) -> bool {
         target.as_any().is::<Self>()
     }
     fn subtypes(&self, acc: &mut Type) {