diff --git a/src/draw.rs b/src/draw.rs
index 67ee223..29dbac7 100644
--- a/src/draw.rs
+++ b/src/draw.rs
@@ -1,85 +1,17 @@
 use crate::*;
 pub use crate::space::*;
 
-/// Implement the [Draw] trait for a particular drawable and [Screen].
-///
-/// ```
-/// use tengri::{*, draw::*, term::*};
-/// struct MyDrawable;
-/// impl_draw!(|self: MyDrawable, to: Tui|{
-///   todo!()
-/// });
-/// ```
-#[macro_export] macro_rules! impl_draw ((|
-    $self:ident:$Self:ty, $to:ident:$To:ty
-|$draw:block)=>{ impl Draw<$To> for $Self {
-    fn draw ($self, $to: &mut $To) -> Usually<XYWH<u16>> $draw
-} });
+mod draw;
+pub use self::draw::*;
 
-/// Drawable that supports dynamic dispatch.
-///
-/// Drawables are composable, e.g. the [when] and [either] conditionals
-/// or the layout constraints.
-///
-/// Drawables are consumable, i.e. the [Draw::draw] method receives an
-/// owned `self` and does not return it, consuming the drawable.
-///
-/// To draw a thing multiple times, instead of explicitly constructing it
-/// every time, implement the [View] trait instead, which will construct
-/// a [Draw]able.
-/// 
-/// ```
-/// use tengri::{*, draw::*};
-/// struct TestScreen(bool);
-/// impl Screen for TestScreen { type Unit = u16; }
-/// impl X<u16> for TestScreen { fn x (&self) -> u16 { 0 } }
-/// impl Y<u16> for TestScreen { fn y (&self) -> u16 { 0 } }
-/// struct TestWidget(bool);
-/// impl Draw<TestScreen> for TestWidget {
-///     fn draw (self, screen: &mut TestScreen) -> Usually<XYWH<u16>> {
-///         screen.0 |= self.0;
-///     }
-/// }
-/// let mut screen = TestScreen(false);
-/// TestWidget(false).draw(&mut screen);
-/// TestWidget(true).draw(&mut screen);
-/// TestWidget(false).draw(&mut screen);
-/// ```
-pub trait Draw<T: Screen> {
-    fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>>;
-}
-impl<T: Screen, D: Draw<T>> Draw<T> for &D {
-    fn draw (self, __: &mut T) -> Usually<XYWH<T::Unit>> {
-        todo!()
-    }
-}
-impl<T: Screen, D: Draw<T>> Draw<T> for Option<D> {
-    fn draw (self, __: &mut T) -> Usually<XYWH<T::Unit>> {
-        todo!()
-    }
-}
+mod view;
+pub use self::view::*;
 
-/// Emit a [Draw]able.
-///
-/// Speculative. How to avoid conflicts with [Draw] proper?
-pub trait View<T: Screen> {
-    fn view (&self) -> impl Draw<T>;
-}
+mod thunk;
+pub use self::thunk::*;
 
-pub const fn thunk <T: Screen, F: FnOnce(&mut T)->Usually<XYWH<T::Unit>>> (draw: F) -> Thunk<T, F> {
-    Thunk(draw, std::marker::PhantomData)
-}
-
-/// Because we can't implement [Draw] for `F: FnOnce...` without conflicts.
-pub struct Thunk<T: Screen, F: FnOnce(&mut T)->Usually<XYWH<T::Unit>>>(
-    pub F,
-    std::marker::PhantomData<T>
-);
-impl<T: Screen, F: FnOnce(&mut T)->Usually<XYWH<T::Unit>>> Draw<T> for Thunk<T, F> {
-    fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>> {
-        (self.0)(to)
-    }
-}
+mod screen;
+pub use self::screen::*;
 
 /// Only render when condition is true.
 ///
@@ -104,36 +36,3 @@ pub const fn when <T: Screen> (condition: bool, draw: impl Draw<T>) -> impl Draw
 pub const fn either <T: Screen> (condition: bool, a: impl Draw<T>, b: impl Draw<T>) -> impl Draw<T> {
     thunk(move|to: &mut T|if condition { a.draw(to) } else { b.draw(to) })
 }
-
-/// Output target.
-///
-/// ```
-/// use tengri::{*, draw::*};
-///
-/// struct TestOut<T: Screen<Unit = u16>>(T);
-///
-/// impl<T: Screen<Unit = u16>> Screen for TestOut {
-///     type Unit = u16;
-///     fn place_at <D: Draw<Self> + ?Sized> (&mut self, area: T, _: D) {
-///         println!("placed: {area:?}");
-///         ()
-///     }
-/// }
-///
-/// impl_draw!(|self: String, to: TestOut<u16>|{
-///    to.area_mut().set_w(self.len() as u16);
-/// });
-/// ```
-pub trait Screen: Space<Self::Unit> + Send + Sync + Sized {
-    type Unit: Coord;
-    /// Render drawable in area.
-    fn place <'t, T: Draw<Self> + ?Sized> (&mut self, content: &'t T) {
-        self.place_at(self.xywh(), content)
-    }
-    /// Render drawable in subarea specified by `area`
-    fn place_at <'t, T: Draw<Self> + ?Sized> (
-        &mut self, _area: XYWH<Self::Unit>, _content: &'t T
-    ) {
-        unimplemented!()
-    }
-}
diff --git a/src/draw/draw.rs b/src/draw/draw.rs
new file mode 100644
index 0000000..8701084
--- /dev/null
+++ b/src/draw/draw.rs
@@ -0,0 +1,60 @@
+use super::*;
+
+/// Implement the [Draw] trait for a particular drawable and [Screen].
+///
+/// ```
+/// use tengri::{*, draw::*, term::*};
+/// struct MyDrawable;
+/// impl_draw!(|self: MyDrawable, to: Tui|{
+///   todo!()
+/// });
+/// ```
+#[macro_export] macro_rules! impl_draw ((|
+    $self:ident:$Self:ty, $to:ident:$To:ty
+|$draw:block)=>{ impl Draw<$To> for $Self {
+    fn draw ($self, $to: &mut $To) -> Usually<XYWH<u16>> $draw
+} });
+
+/// Drawable that supports dynamic dispatch.
+///
+/// Drawables are composable, e.g. the [when] and [either] conditionals
+/// or the layout constraints.
+///
+/// Drawables are consumable, i.e. the [Draw::draw] method receives an
+/// owned `self` and does not return it, consuming the drawable.
+///
+/// To draw a thing multiple times, instead of explicitly constructing it
+/// every time, implement the [View] trait instead, which will construct
+/// a [Draw]able.
+/// 
+/// ```
+/// use tengri::{*, draw::*};
+/// struct MyScreen(bool);
+/// impl Screen for MyScreen { type Unit = u16; }
+/// impl X<u16> for MyScreen { fn x (&self) -> u16 { 0 } }
+/// impl Y<u16> for MyScreen { fn y (&self) -> u16 { 0 } }
+/// struct MyWidget(bool);
+/// impl Draw<MyScreen> for MyWidget {
+///     fn draw (self, screen: &mut MyScreen) -> Usually<XYWH<u16>> {
+///         screen.0 |= self.0;
+///     }
+/// }
+/// let mut screen = MyScreen(false);
+/// MyWidget(false).draw(&mut screen);
+/// MyWidget(true).draw(&mut screen);
+/// MyWidget(false).draw(&mut screen);
+/// ```
+pub trait Draw<T: Screen> {
+    fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>>;
+}
+impl<T: Screen, D: Draw<T>> Draw<T> for &D {
+    fn draw (self, __: &mut T) -> Usually<XYWH<T::Unit>> {
+        todo!()
+    }
+}
+impl<T: Screen, D: Draw<T>> Draw<T> for Option<D> {
+    fn draw (self, __: &mut T) -> Usually<XYWH<T::Unit>> {
+        todo!()
+    }
+}
+
diff --git a/src/draw/screen.rs b/src/draw/screen.rs
new file mode 100644
index 0000000..dc51744
--- /dev/null
+++ b/src/draw/screen.rs
@@ -0,0 +1,34 @@
+use super::*;
+
+/// Output target.
+///
+/// ```
+/// use tengri::{*, draw::*};
+///
+/// struct TestOut<T: Screen<Unit = u16>>(T);
+///
+/// impl<T: Screen<Unit = u16>> Screen for TestOut {
+///     type Unit = u16;
+///     fn place_at <D: Draw<Self> + ?Sized> (&mut self, area: T, _: D) {
+///         println!("placed: {area:?}");
+///         ()
+///     }
+/// }
+///
+/// impl_draw!(|self: String, to: TestOut<u16>|{
+///    to.area_mut().set_w(self.len() as u16);
+/// });
+/// ```
+pub trait Screen: Space<Self::Unit> + Send + Sync + Sized {
+    type Unit: Coord;
+    /// Render drawable in area.
+    fn place <'t, T: Draw<Self> + ?Sized> (&mut self, content: &'t T) {
+        self.place_at(self.xywh(), content)
+    }
+    /// Render drawable in subarea specified by `area`
+    fn place_at <'t, T: Draw<Self> + ?Sized> (
+        &mut self, _area: XYWH<Self::Unit>, _content: &'t T
+    ) {
+        unimplemented!()
+    }
+}
diff --git a/src/draw/thunk.rs b/src/draw/thunk.rs
new file mode 100644
index 0000000..9b1d4b5
--- /dev/null
+++ b/src/draw/thunk.rs
@@ -0,0 +1,16 @@
+use super::*;
+
+pub const fn thunk <T: Screen, F: FnOnce(&mut T)->Usually<XYWH<T::Unit>>> (draw: F) -> Thunk<T, F> {
+    Thunk(draw, std::marker::PhantomData)
+}
+
+/// Because we can't implement [Draw] for `F: FnOnce...` without conflicts.
+pub struct Thunk<T: Screen, F: FnOnce(&mut T)->Usually<XYWH<T::Unit>>>(
+    pub F,
+    std::marker::PhantomData<T>
+);
+impl<T: Screen, F: FnOnce(&mut T)->Usually<XYWH<T::Unit>>> Draw<T> for Thunk<T, F> {
+    fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>> {
+        (self.0)(to)
+    }
+}
diff --git a/src/draw/view.rs b/src/draw/view.rs
new file mode 100644
index 0000000..82fe908
--- /dev/null
+++ b/src/draw/view.rs
@@ -0,0 +1,8 @@
+use super::*;
+
+/// Emit a [Draw]able.
+///
+/// Speculative. How to avoid conflicts with [Draw] proper?
+pub trait View<T: Screen> {
+    fn view (&self) -> impl Draw<T>;
+}
diff --git a/src/eval.rs b/src/eval.rs
index c87eb56..4fc5934 100644
--- a/src/eval.rs
+++ b/src/eval.rs
@@ -172,11 +172,11 @@ pub fn eval_view <'a, O: Screen + 'a, S> (
 /// # fn main () -> tengri::Usually<()> {
 /// let state = State;
 /// let mut out = Tui::default();
-/// tengri::eval_view_tui(&state, &mut out, "")?;
-/// tengri::eval_view_tui(&state, &mut out, "text Hello world!")?;
-/// tengri::eval_view_tui(&state, &mut out, "fg (g 0) (text Hello world!)")?;
-/// tengri::eval_view_tui(&state, &mut out, "bg (g 2) (text Hello world!)")?;
-/// tengri::eval_view_tui(&state, &mut out, "(bg (g 3) (fg (g 4) (text Hello world!)))")?;
+/// tengri::eval::eval_view_tui(&state, &mut out, "")?;
+/// tengri::eval::eval_view_tui(&state, &mut out, "text Hello world!")?;
+/// tengri::eval::eval_view_tui(&state, &mut out, "fg (g 0) (text Hello world!)")?;
+/// tengri::eval::eval_view_tui(&state, &mut out, "bg (g 2) (text Hello world!)")?;
+/// tengri::eval::eval_view_tui(&state, &mut out, "(bg (g 3) (fg (g 4) (text Hello world!)))")?;
 /// # Ok(()) }
 /// ```
 pub fn eval_view_tui <'a, S> (
diff --git a/src/sing.rs b/src/sing.rs
index 7716129..cd76eb2 100644
--- a/src/sing.rs
+++ b/src/sing.rs
@@ -52,7 +52,7 @@ pub trait Audio {
 /// Event enum for JACK events.
 ///
 /// ```
-/// let event = tengri::JackEvent::XRun;
+/// let event = tengri::sing::JackEvent::XRun; // kerpop
 /// ```
 #[derive(Debug, Clone, PartialEq)] pub enum JackEvent {
     ThreadInit,
@@ -70,7 +70,7 @@ pub trait Audio {
 /// Generic notification handler that emits [JackEvent]
 ///
 /// ```
-/// let notify = tengri::JackNotify(|_|{});
+/// let notify = tengri::sing::JackNotify(|_|{});
 /// ```
 pub struct JackNotify<T: Fn(JackEvent) + Send>(pub T);
 
diff --git a/src/space.rs b/src/space.rs
index a2f7010..9a8650c 100644
--- a/src/space.rs
+++ b/src/space.rs
@@ -1,6 +1,9 @@
 use crate::{*, draw::*};
 #[cfg(test)] use proptest_derive::Arbitrary;
 
+mod coord;
+pub use self::coord::*;
+
 mod xywh;
 pub use self::xywh::*;
 
@@ -10,39 +13,11 @@ pub use self::origin::*;
 mod split;
 pub use self::split::*;
 
-/// A numeric type that can be used as coordinate.
-///
-/// FIXME: Replace with `num` crate?
-/// FIXME: Use AsRef/AsMut?
-///
-/// ```
-/// use tengri::draw::Coord;
-/// let a: u16 = Coord::zero();
-/// let b: u16 = a.plus(1);
-/// let c: u16 = a.minus(2);
-/// let d = a.atomic();
-/// ```
-pub trait Coord: Send + Sync + Copy
-    + Add<Self, Output=Self>
-    + Sub<Self, Output=Self>
-    + Mul<Self, Output=Self>
-    + Div<Self, Output=Self>
-    + Ord + PartialEq + Eq
-    + Debug + Display + Default
-    + From<u16> + Into<u16>
-    + Into<usize>
-    + Into<f64>
-    + std::iter::Step
-{
-    /// Zero in own type.
-    fn zero () -> Self { 0.into() }
-    /// Addition.
-    fn plus (self, other: Self) -> Self;
-    /// Saturating subtraction.
-    fn minus  (self, other: Self) -> Self { if self >= other { self - other } else { 0.into() } }
-    /// Convert to [AtomicUsize].
-    fn atomic (self) -> AtomicUsize { AtomicUsize::new(self.into()) }
-}
+mod iter;
+pub use self::iter::*;
+
+mod size;
+pub use self::size::*;
 
 /// Horizontal axis.
 pub trait X<N: Coord> {
@@ -89,7 +64,7 @@ pub const fn w_exact <T: Screen> (w: T::Unit, c: impl Draw<T>) -> impl Draw<T> {
 /// Shrink drawing area symmetrically.
 ///
 /// ```
-/// let padded = tengri::W(3).pad("Hello");
+/// let padded = tengri::space::w_pad(3, "Hello");
 /// ```
 pub const fn w_pad <T: Screen> (x: T::Unit, draw: impl Draw<T>) -> impl Draw<T> {
     thunk(move|to: &mut T|draw.draw(todo!()))
@@ -139,7 +114,7 @@ pub const fn h_exact <T: Screen> (h: T::Unit, c: impl Draw<T>) -> impl Draw<T> {
 /// Shrink drawing area symmetrically.
 ///
 /// ```
-/// let padded = tengri::W::pad(3, "Hello");
+/// let padded = tengri::space::w_pad(3, "Hello");
 /// ```
 pub const fn h_pad <T: Screen> (x: T::Unit, draw: impl Draw<T>) -> impl Draw<T> {
     thunk(move|to: &mut T|draw.draw(todo!()))
@@ -170,7 +145,7 @@ pub const fn wh_pad <T: Screen> (w: T::Unit, h: T::Unit, draw: impl Draw<T>)
 /// Only draw content if area is above a certain size.
 ///
 /// ```
-/// let min = tengri::wh_min(3, 5, "Hello"); // 5x5
+/// let min = tengri::space::wh_min(3, 5, "Hello"); // 5x5
 /// ```
 pub const fn wh_min <T: Screen> (w: Option<T::Unit>, h: Option<T::Unit>, draw: impl Draw<T>)
     -> impl Draw<T>
@@ -181,7 +156,7 @@ pub const fn wh_min <T: Screen> (w: Option<T::Unit>, h: Option<T::Unit>, draw: i
 /// Set the maximum width and/or height of the content.
 ///
 /// ```
-/// let max = tengri::wh_max(Some(3), Some(5), "Hello");
+/// let max = tengri::space::wh_max(Some(3), Some(5), "Hello");
 /// ```
 pub const fn wh_max <T: Screen> (w: Option<T::Unit>, h: Option<T::Unit>, draw: impl Draw<T>)
     -> impl Draw<T>
@@ -192,7 +167,7 @@ pub const fn wh_max <T: Screen> (w: Option<T::Unit>, h: Option<T::Unit>, draw: i
 /// Set the maximum width and/or height of the content.
 ///
 /// ```
-/// let exact = tengri::wh_exact(Some(3), Some(5), "Hello");
+/// let exact = tengri::space::wh_exact(Some(3), Some(5), "Hello");
 /// ```
 pub const fn wh_exact <T: Screen> (w: Option<T::Unit>, h: Option<T::Unit>, draw: impl Draw<T>)
     -> impl Draw<T>
@@ -202,7 +177,7 @@ pub const fn wh_exact <T: Screen> (w: Option<T::Unit>, h: Option<T::Unit>, draw:
 
 /// Limit size of drawing area
 /// ```
-/// let clipped = tengri::wh_clip(Some(3), Some(5), "Hello");
+/// let clipped = tengri::space::wh_clip(Some(3), Some(5), "Hello");
 /// ```
 pub const fn wh_clip <T: Screen> (
     w: Option<T::Unit>, h: Option<T::Unit>, draw: impl Draw<T>
@@ -213,68 +188,3 @@ pub const fn wh_clip <T: Screen> (
 pub const fn wh_full <T: Screen> (a: impl Draw<T>) -> impl Draw<T> { a }
 pub const fn w_full <T: Screen> (a: impl Draw<T>) -> impl Draw<T> { a }
 pub const fn h_full <T: Screen> (a: impl Draw<T>) -> impl Draw<T> { a }
-
-/// Iterate over a collection of renderables:
-///
-/// ```
-/// use tengri::draw::{Origin::*, Split::*};
-/// let _ = Below.iter([
-///   NW.align(W(15).max(W(10).min("Leftbar"))),
-///   NE.align(W(12).max(W(10).min("Rightbar"))),
-///   Center.align(W(40).max(H(20.max("Center"))))
-/// ].iter(), |x|x);
-/// ```
-pub fn iter <
-    S: Screen,
-    D: Draw<S>,
-    V: Fn()->I,
-    I: Iterator<Item = D>,
-    F: Fn(&D)->dyn Draw<S>,
-> (_items: V, _cb: F) -> impl Draw<S> {
-    thunk(move|_to: &mut S|{ todo!() })
-}
-
-pub fn iter_north <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
-    _iter: impl Fn()->I, _draw: impl Fn(D)->U,
-) -> impl Draw<S> {
-    thunk(move|_to: &mut S|{ todo!() })
-}
-
-pub fn iter_east <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
-    _iter: impl Fn()->I, _draw: impl Fn(D)->U,
-) -> impl Draw<S> {
-    thunk(move|_to: &mut S|{ todo!() })
-}
-
-pub fn iter_south <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
-    _iter: impl Fn()->I, _draw: impl Fn(D)->U,
-) -> impl Draw<S> {
-    thunk(move|_to: &mut S|{ todo!() })
-}
-
-pub fn iter_west <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
-    _iter: impl Fn()->I, _draw: impl Fn(D)->U,
-) -> impl Draw<S> {
-    thunk(move|_to: &mut S|{ todo!() })
-}
-
-#[derive(Default, Debug)]
-pub struct Size(AtomicUsize, AtomicUsize);
-impl X<u16> for Size {
-    fn x (&self) -> u16 { 0 }
-    fn w (&self) -> u16 { self.0.load(Relaxed) as u16 }
-}
-impl Y<u16> for Size {
-    fn y (&self) -> u16 { 0 }
-    fn h (&self) -> u16 { self.1.load(Relaxed) as u16 }
-}
-impl Size {
-    pub const fn of <T: Screen> (&self, of: impl Draw<T>) -> impl Draw<T> {
-        thunk(move|to: &mut T|{
-            let area = of.draw(to)?;
-            self.0.store(area.w().into(), Relaxed);
-            self.1.store(area.h().into(), Relaxed);
-            Ok(area)
-        })
-    }
-}
diff --git a/src/space/coord.rs b/src/space/coord.rs
new file mode 100644
index 0000000..f5e6974
--- /dev/null
+++ b/src/space/coord.rs
@@ -0,0 +1,35 @@
+use super::*;
+
+/// A numeric type that can be used as coordinate.
+///
+/// FIXME: Replace with `num` crate?
+/// FIXME: Use AsRef/AsMut?
+///
+/// ```
+/// use tengri::draw::Coord;
+/// let a: u16 = Coord::zero();
+/// let b: u16 = a.plus(1);
+/// let c: u16 = a.minus(2);
+/// let d = a.atomic();
+/// ```
+pub trait Coord: Send + Sync + Copy
+    + Add<Self, Output=Self>
+    + Sub<Self, Output=Self>
+    + Mul<Self, Output=Self>
+    + Div<Self, Output=Self>
+    + Ord + PartialEq + Eq
+    + Debug + Display + Default
+    + From<u16> + Into<u16>
+    + Into<usize>
+    + Into<f64>
+    + std::iter::Step
+{
+    /// Zero in own type.
+    fn zero () -> Self { 0.into() }
+    /// Addition.
+    fn plus (self, other: Self) -> Self;
+    /// Saturating subtraction.
+    fn minus  (self, other: Self) -> Self { if self >= other { self - other } else { 0.into() } }
+    /// Convert to [AtomicUsize].
+    fn atomic (self) -> AtomicUsize { AtomicUsize::new(self.into()) }
+}
diff --git a/src/space/iter.rs b/src/space/iter.rs
new file mode 100644
index 0000000..4bcfde8
--- /dev/null
+++ b/src/space/iter.rs
@@ -0,0 +1,46 @@
+use super::*;
+
+/// Iterate over a collection of renderables:
+///
+/// ```
+/// use tengri::draw::{Origin::*, Split::*};
+/// let _ = Below.iter([
+///   NW.align(W(15).max(W(10).min("Leftbar"))),
+///   NE.align(W(12).max(W(10).min("Rightbar"))),
+///   Center.align(W(40).max(H(20.max("Center"))))
+/// ].iter(), |x|x);
+/// ```
+pub fn iter <
+    S: Screen,
+    D: Draw<S>,
+    V: Fn()->I,
+    I: Iterator<Item = D>,
+    F: Fn(&D)->dyn Draw<S>,
+> (_items: V, _cb: F) -> impl Draw<S> {
+    thunk(move|_to: &mut S|{ todo!() })
+}
+
+pub fn iter_north <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
+    _iter: impl Fn()->I, _draw: impl Fn(D)->U,
+) -> impl Draw<S> {
+    thunk(move|_to: &mut S|{ todo!() })
+}
+
+pub fn iter_east <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
+    _iter: impl Fn()->I, _draw: impl Fn(D)->U,
+) -> impl Draw<S> {
+    thunk(move|_to: &mut S|{ todo!() })
+}
+
+pub fn iter_south <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
+    _iter: impl Fn()->I, _draw: impl Fn(D)->U,
+) -> impl Draw<S> {
+    thunk(move|_to: &mut S|{ todo!() })
+}
+
+pub fn iter_west <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
+    _iter: impl Fn()->I, _draw: impl Fn(D)->U,
+) -> impl Draw<S> {
+    thunk(move|_to: &mut S|{ todo!() })
+}
+
diff --git a/src/space/origin.rs b/src/space/origin.rs
index 256a7f6..f3f7acc 100644
--- a/src/space/origin.rs
+++ b/src/space/origin.rs
@@ -73,7 +73,7 @@ impl<T: Screen, U: Draw<T>> Draw<T> for Anchor<U> {
 ///
 /// ```
 /// use tengri::draw::Origin;
-/// let _ = Origin::NW.align(())
+/// let _ = Origin::NW.align(());
 /// ```
 #[cfg_attr(test, derive(Arbitrary))]
 #[derive(Debug, Copy, Clone, Default)] pub enum Origin {
diff --git a/src/space/size.rs b/src/space/size.rs
new file mode 100644
index 0000000..add71ae
--- /dev/null
+++ b/src/space/size.rs
@@ -0,0 +1,28 @@
+use super::*;
+
+/// Uses [AtomicUsize] to measure size during\
+/// rendering (which is normally read-only).
+#[derive(Default, Debug)]
+pub struct Size(AtomicUsize, AtomicUsize);
+
+impl X<u16> for Size {
+    fn x (&self) -> u16 { 0 }
+    fn w (&self) -> u16 { self.0.load(Relaxed) as u16 }
+}
+
+impl Y<u16> for Size {
+    fn y (&self) -> u16 { 0 }
+    fn h (&self) -> u16 { self.1.load(Relaxed) as u16 }
+}
+
+impl Size {
+    pub const fn of <T: Screen> (&self, of: impl Draw<T>) -> impl Draw<T> {
+        thunk(move|to: &mut T|{
+            let area = of.draw(to)?;
+            self.0.store(area.w().into(), Relaxed);
+            self.1.store(area.h().into(), Relaxed);
+            Ok(area)
+        })
+    }
+}
+
diff --git a/src/space/split.rs b/src/space/split.rs
index fabcb6b..f6f53b2 100644
--- a/src/space/split.rs
+++ b/src/space/split.rs
@@ -39,12 +39,12 @@ impl Split {
 
     /// ```
     /// use tengri::draw::Split::*;
-    /// let _ = Above.bsp((), ());
-    /// let _ = Below.bsp((), ());
-    /// let _ = North.bsp((), ());
-    /// let _ = South.bsp((), ());
-    /// let _ = East.bsp((), ());
-    /// let _ = West.bsp((), ());
+    /// let _ = Above.half("", "");
+    /// let _ = Below.half("", "");
+    /// let _ = North.half("", "");
+    /// let _ = South.half("", "");
+    /// let _ = East.half("", "");
+    /// let _ = West.half("", "");
     /// ```
     pub const fn half <T: Screen> (&self, a: impl Draw<T>, b: impl Draw<T>) -> impl Draw<T> {
         thunk(move|to: &mut T|{
diff --git a/src/space/xywh.rs b/src/space/xywh.rs
index a4047db..c403f5a 100644
--- a/src/space/xywh.rs
+++ b/src/space/xywh.rs
@@ -3,8 +3,9 @@ use super::*;
 /// Point with size.
 ///
 /// ```
-/// let xywh = tengri::XYWH(0u16, 0, 0, 0);
-/// assert_eq!(tengri::XYWH(10u16, 10, 20, 20).center(), tengri::XY(20, 20));
+/// use tengri::space::{XY, XYWH};
+/// let xywh = XYWH(0u16, 0, 0, 0);
+/// assert_eq!(XYWH(10u16, 10, 20, 20).center(), XY(20, 20));
 /// ```
 ///
 /// * [ ] TODO: origin field (determines at which corner/side is X0 Y0)
diff --git a/src/term.rs b/src/term.rs
index 2251432..4be440c 100644
--- a/src/term.rs
+++ b/src/term.rs
@@ -645,9 +645,9 @@ pub const fn border <T, S: BorderStyle> (on: bool, style: S, draw: impl Draw<Tui
 /// Draw TUI content or its error message.
 ///
 /// ```
-/// let _ = tengri::tui::catcher(Ok(Some("hello")));
-/// let _ = tengri::tui::catcher(Ok(None));
-/// let _ = tengri::tui::catcher(Err("draw fail".into()));
+/// let _ = tengri::term::catcher(Ok(Some("hello")));
+/// let _ = tengri::term::catcher(Ok(None));
+/// let _ = tengri::term::catcher(Err("draw fail".into()));
 /// ```
 pub fn catcher <T: Draw<Tui>> (result: Usually<T>) -> impl Draw<Tui> {
     thunk(move|to: &mut Tui|match result {