diff --git a/.envrc b/.envrc
deleted file mode 100644
index 1d953f4..0000000
--- a/.envrc
+++ /dev/null
@@ -1 +0,0 @@
-use nix
diff --git a/.gitignore b/.gitignore
index 4f90c40..8899d91 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,3 @@
-*.profraw
-.direnv
-cov
 target
+cov
+*.profraw
diff --git a/Cargo.toml b/Cargo.toml
index 8657a68..b0fd6fa 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -37,7 +37,7 @@ winit         = { optional = true, version = "0.30.4", features = [ "x11" ]}
 [dev-dependencies]
 proptest        = { version = "^1" }
 proptest-derive = { version = "^0.5.1" }
-tengri          = { path = "." }
+tengri          = { path = ".", features = [ "dsl" ] }
 #tengri_proc     = { path = "./proc" }
 
 [profile.coverage]
diff --git a/Justfile b/Justfile
index 8d7c790..1d5f794 100644
--- a/Justfile
+++ b/Justfile
@@ -2,9 +2,8 @@ export LLVM_PROFILE_FILE := "cov/cargo-test-%p-%m.profraw"
 grcov-binary := "--binary-path ./target/coverage/deps/"
 grcov-ignore := "--ignore-not-existing --ignore '../*' --ignore \"/*\" --ignore 'target/*'"
 
-[private]
 default:
-  @just -l
+  just -l
 
 bacon:
   bacon -s
@@ -30,7 +29,6 @@ doc:
     cargo doc
 
 example-tui-00:
-  cargo run --example tui_00
-
+  cargo run -p tengri_tui --example tui_00
 example-tui-01:
-  cargo run --example tui_01
+  cargo run -p tengri_tui --example tui_01
diff --git a/examples/tui_00.rs b/examples/tui_00.rs
index 929c56d..80e7acd 100644
--- a/examples/tui_00.rs
+++ b/examples/tui_00.rs
@@ -1,74 +1,46 @@
-use ::{
-    std::{io::stdout, sync::{Arc, RwLock}},
-    tengri::{*, term::*, lang::*, keys::*, draw::*, space::*},
-    ratatui::style::Color,
-};
-
-tui_main!(State { cursor: 10, ..Default::default() });
-
-impl Apply<TuiEvent, Usually<Self>> for State {
-    fn apply (&mut self, input: &TuiEvent) -> Usually<Self> {
-        todo!()
-    }
-}
-
-impl View<Tui> for State {
-    fn view (&self) -> impl Draw<Tui> {
-        let index   = self.cursor + 1;
-        let wh      = (self.size.w(), self.size.h());
-        let src     = VIEWS.get(self.cursor).unwrap_or(&"");
-        let heading = format!("State {}/{} in {:?}", index, VIEWS.len(), &wh);
-        let title   = bg(Color::Rgb(60, 10, 10), push_y(1, align_n(heading)));
-        let code    = bg(Color::Rgb(10, 60, 10), push_y(2, align_n(format!("{}", src))));
-        //let content = ;//();//bg(Color::Rgb(10, 10, 60), View(self, CstIter::new(src)));
-        self.size.of(bsp_s(title, bsp_n(code, self.understand(to, &src).unwrap())))
-    }
-}
-
+use ::{std::{io::stdout, sync::{Arc, RwLock}}, ratatui::style::Color, tengri::*};
+ tui_main!(State { cursor: 10, ..Default::default() });
+namespace!(State: bool  {});
+namespace!(State: u16   {});
+namespace!(State: Color {});
+   handle!(TuiIn: |self: State, input|Action::from(input).eval(self).map(|_|None));
+     view!(State: TuiOut: [ evaluate_output_expression, evaluate_output_expression_tui ]);
+     draw!(State: TuiOut: [ draw_example ]);
 #[derive(Debug, Default)] struct State {
-    /** Command history (undo/redo). */
-    history: Vec<Action>,
-    /** User-controllable value. */
-    cursor: usize,
-    /** Rendered window size. */
-    size: crate::space::Size,
+    /** Rendered window size        */ size:    Measure<TuiOut>,
+    /** Command history (undo/redo) */ history: Vec<Action>,
+    /** User-controllable value     */ cursor:  usize,
 }
-
-//impl_from!(Action: |input: &TuiIn| todo!());
+impl_from!(Action: |input: &TuiIn| todo!());
 #[derive(Debug)] enum Action {
-    /** Increment cursor */
-    Next,
-    /** Decrement cursor */
-    Prev
+    /** Increment cursor */ Next,
+    /** Decrement cursor */ Prev
 }
-
-fn draw_example (state: &State, to: &mut Tui) {
+fn draw_example (state: &State, to: &mut TuiOut) {
+    let index   = state.cursor + 1;
+    let wh      = state.size.wh();
+    let src     = VIEWS.get(state.cursor).unwrap_or(&"");
+    let heading = format!("State {}/{} in {:?}", index, VIEWS.len(), &wh);
+    let title   = Tui::bg(Color::Rgb(60, 10, 10), Push::Y(1, Align::n(heading)));
+    let code    = Tui::bg(Color::Rgb(10, 60, 10), Push::Y(2, Align::n(format!("{}", src))));
+    //let content = ;//();//Tui::bg(Color::Rgb(10, 10, 60), View(state, CstIter::new(src)));
+    state.size.of(Bsp::s(title, Bsp::n(code, state.understand(to, &src).unwrap()))).draw(to)
 }
-
 impl Action {
-
-    const BINDS: &'static str = stringify! {
-        (@left  prev)
-        (@right next)
-    };
-
+    const BINDS: &'static str = stringify! { (@left prev) (@right next) };
     fn eval (&self, state: &mut State) -> Perhaps<Self> {
         use Action::*;
         match self { Next => Self::next(state), Prev => Self::prev(state), }
     }
-
     fn next (state: &mut State) -> Perhaps<Self> {
         state.cursor = (state.cursor + 1) % VIEWS.len();
         Ok(Some(Self::Prev))
     }
-
     fn prev (state: &mut State) -> Perhaps<Self> {
         state.cursor = if state.cursor > 0 { state.cursor - 1 } else { VIEWS.len() - 1 };
         Ok(Some(Self::Next))
     }
-
 }
-
 const VIEWS: &'static [&'static str] = &[
 
     stringify! { :hello-world },
@@ -149,10 +121,3 @@ const VIEWS: &'static [&'static str] = &[
     },
 
 ];
-
-//namespace!(State: bool  {});
-//namespace!(State: u16   {});
-//namespace!(State: Color {});
-   //handle!(TuiIn: |self: State, input|Action::from(input).eval(self).map(|_|None));
-     //view!(State: Tui: [ evaluate_output_expression, evaluate_output_expression_tui ]);
-     //draw!(State: Tui: [ draw_example ]);
diff --git a/shell.nix b/shell.nix
index f34dc1f..a4c3248 100644
--- a/shell.nix
+++ b/shell.nix
@@ -2,8 +2,8 @@
 {pkgs?import<nixpkgs>{}}:let
   stdenv            = pkgs.clang19Stdenv;
   name              = "tengri";
-  nativeBuildInputs = [ pkgs.pkg-config pkgs.clang pkgs.libclang pkgs.mold ];
-  buildInputs       = [ pkgs.libclang pkgs.jack2 ];
+  nativeBuildInputs = [ pkgs.pkg-config pkgs.libclang pkgs.mold ];
+  buildInputs       = [ pkgs.libclang ];
   LIBCLANG_PATH     = "${pkgs.libclang.lib.outPath}/lib";
   LD_LIBRARY_PATH   = pkgs.lib.makeLibraryPath [];
 in pkgs.mkShell.override {
diff --git a/src/color.rs b/src/color.rs
index f16358a..13caf71 100644
--- a/src/color.rs
+++ b/src/color.rs
@@ -11,10 +11,6 @@ pub fn rgb (r: u8, g: u8, b: u8) -> ItemColor {
     ItemColor { okhsl: rgb_to_okhsl(term), term }
 }
 
-pub fn g (g: u8) -> Color {
-    Color::Rgb(g, g, g)
-}
-
 pub fn okhsl_to_rgb (color: Okhsl<f32>) -> Color {
     let Srgb { red, green, blue, .. }: Srgb<f32> = Srgb::from_color_unclamped(color);
     Color::Rgb((red   * 255.0) as u8, (green * 255.0) as u8, (blue  * 255.0) as u8,)
diff --git a/src/draw.rs b/src/draw.rs
index ad47922..9b8ebdb 100644
--- a/src/draw.rs
+++ b/src/draw.rs
@@ -7,10 +7,6 @@ use crate::{*, lang::*, color::*, space::*};
 ///
 /// 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::*;
@@ -30,22 +26,17 @@ use crate::{*, lang::*, color::*, space::*};
 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, to: &mut T) -> Usually<XYWH<T::Unit>> {
-        todo!()
-    }
-}
-impl<T: Screen, D: Draw<T>> Draw<T> for Option<D> {
-    fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>> {
-        todo!()
+
+impl<T: Screen> Draw<T> for () {
+    fn draw (self, __: &mut T) -> Usually<XYWH<T::Unit>> {
+        Ok(Default::default())
     }
 }
 
-/// Emit a [Draw]able.
-///
-/// Speculative. How to avoid conflicts with [Draw] proper?
-pub trait View<T: Screen> {
-    fn view (&self) -> impl Draw<T>;
+impl<T: Screen, D: Draw<T>> Draw<T> for Option<D> {
+    fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>> {
+        Ok(self.map(|draw|draw.draw(to)).transpose()?.unwrap_or_default())
+    }
 }
 
 pub const fn thunk <T: Screen, F: FnOnce(&mut T)->Usually<XYWH<T::Unit>>> (draw: F) -> Thunk<T, F> {
@@ -57,6 +48,7 @@ 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)
@@ -119,3 +111,14 @@ pub trait Screen: Space<Self::Unit> + Send + Sync + Sized {
         unimplemented!()
     }
 }
+
+/// Emit a [Draw]able.
+pub trait View<T: Screen> {
+    fn view (&self) -> impl Draw<T>;
+}
+
+impl<T: Screen, V: View<T>> Draw<T> for &V {
+    fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>> {
+        self.view().draw(to)
+    }
+}
diff --git a/src/exit.rs b/src/exit.rs
index 0b79708..2d07816 100644
--- a/src/exit.rs
+++ b/src/exit.rs
@@ -8,10 +8,3 @@ impl Exit {
         run(Self(Arc::new(AtomicBool::new(false))))
     }
 }
-
-impl AsRef<Arc<AtomicBool>> for Exit {
-    fn as_ref (&self) -> &Arc<AtomicBool> {
-        &self.0
-    }
-}
-
diff --git a/src/keys.rs b/src/keys.rs
index 9cc54e1..2d2037c 100644
--- a/src/keys.rs
+++ b/src/keys.rs
@@ -2,13 +2,13 @@ use crate::task::Task;
 
 use ::std::sync::{Arc, RwLock, atomic::{AtomicBool, Ordering::*}};
 use ::std::time::Duration;
-use ::dizzle::{Usually, Apply, impl_from};
+use ::dizzle::{Usually, Do, impl_from};
 use ::crossterm::event::{
     read, Event, KeyEvent, KeyCode, KeyModifiers, KeyEventKind, KeyEventState
 };
 
 /// Spawn the TUI input thread which reads keys from the terminal.
-pub fn tui_input <T: Apply<TuiEvent, Usually<T>> + Send + Sync + 'static> (
+pub fn tui_input <T: Do<TuiEvent, Usually<T>> + Send + Sync + 'static> (
     exited: &Arc<AtomicBool>, state: &Arc<RwLock<T>>, poll: Duration
 ) -> Result<Task, std::io::Error> {
     let exited = exited.clone();
diff --git a/src/space.rs b/src/space.rs
index 0bb159a..b942f74 100644
--- a/src/space.rs
+++ b/src/space.rs
@@ -1,5 +1,4 @@
 use crate::{*, draw::*};
-#[cfg(test)] use proptest_derive::Arbitrary;
 
 /// Point with size.
 ///
@@ -424,26 +423,22 @@ 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 }
 
 #[macro_export] macro_rules! north {
-    ($head:expr $(,)?) => { $head };
-    ($head:expr, $($tail:expr),* $(,)?) => { north($head, north!($($tail,)*)) };
+    ($($tt:tt)*) => { unimplemented!() };
 }
 #[macro_export] macro_rules! south {
-    ($head:expr $(,)?) => { $head };
-    ($head:expr, $($tail:expr),* $(,)?) => { south($head, south!($($tail,)*)) };
+    ($($tt:tt)*) => { unimplemented!() };
 }
 #[macro_export] macro_rules! east {
-    ($head:expr $(,)?) => { $head };
-    ($head:expr, $($tail:expr),* $(,)?) => { east($head, east!($($tail,)*)) };
+    ($($tt:tt)*) => { unimplemented!() };
 }
 #[macro_export] macro_rules! west {
-    ($head:expr $(, $tail:expr)* $(,)?) => { west($head, west!($($tail,)*)) };
+    ($($tt:tt)*) => { unimplemented!() };
 }
 #[macro_export] macro_rules! above {
-    ($head:expr $(, $tail:expr)* $(,)?) => { above($head, above!($($tail,)*)) };
+    ($($tt:tt)*) => { unimplemented!() };
 }
 #[macro_export] macro_rules! below {
-    ($head:expr $(,)?) => { $head };
-    ($head:expr, $($tail:expr),* $(,)?) => { below($head, below!($($tail,)*)) };
+    ($($tt:tt)*) => { unimplemented!() };
 }
 
 /// Iterate over a collection of renderables:
@@ -457,56 +452,42 @@ pub const fn h_full <T: Screen> (a: impl Draw<T>) -> impl Draw<T> { a }
 /// ].iter(), |x|x);
 /// ```
 pub fn iter <
-    S: Screen,
-    D: Draw<S>,
+    T: Screen,
     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!() })
+    I: Iterator<Item = dyn Draw<T>>,
+    F: Fn(&dyn Draw<T>)->dyn Draw<T>,
+> (_items: V, _cb: F) -> impl Draw<T> {
+    thunk(move|_to: &mut T|{ 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_north <
+    T: Screen,
+    V: Fn()->I,
+    I: Iterator<Item = dyn Draw<T>>,
+    F: Fn(&dyn Draw<T>)->dyn Draw<T>,
+> (_items: V, _cb: F) -> impl Draw<T> {
+    thunk(move|_to: &mut T|{ 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_east <
+    T: Screen,
+    V: Fn()->I,
+    I: Iterator<Item = dyn Draw<T>>,
+    F: Fn(&dyn Draw<T>)->dyn Draw<T>,
+> (_items: V, _cb: F) -> impl Draw<T> {
+    thunk(move|_to: &mut T|{ 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_south <
+    T: Screen,
+    V: Fn()->I,
+    I: Iterator<Item = dyn Draw<T>>,
+    F: Fn(&dyn Draw<T>)->dyn Draw<T>,
+> (_items: V, _cb: F) -> impl Draw<T> {
+    thunk(move|_to: &mut T|{ 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)
-        })
-    }
+pub fn iter_west <
+    T: Screen,
+    V: Fn()->I,
+    I: Iterator<Item = dyn Draw<T>>,
+    F: Fn(&dyn Draw<T>)->dyn Draw<T>,
+> (_items: V, _cb: F) -> impl Draw<T> {
+    thunk(move|_to: &mut T|{ todo!() })
 }
diff --git a/src/term.rs b/src/term.rs
index ff8496d..32081c4 100644
--- a/src/term.rs
+++ b/src/term.rs
@@ -21,23 +21,6 @@ use ::{
         event::{poll, read, Event, KeyEvent, KeyCode, KeyModifiers, KeyEventKind, KeyEventState},
     }
 };
-#[macro_export] macro_rules! tui_main {
-    ($state:expr) => {
-        pub fn main () -> Usually<()> {
-            tengri::exit::Exit::run(|exit|{
-                let state = Arc::new(RwLock::new($state));
-                Ok((
-                    ::tengri::keys::tui_input(
-                        exit.as_ref(), &state, std::time::Duration::from_millis(100)
-                    )?,
-                    ::tengri::term::tui_output(
-                        stdout(), exit.as_ref(), &state, std::time::Duration::from_millis(10)
-                    )?
-                ))
-            })
-        }
-    }
-}
 pub struct Tui(pub Buffer, pub XYWH<u16>);
 impl Screen    for Tui { type Unit = u16; }
 impl Deref     for Tui { type Target = Buffer; fn deref (&self) -> &Buffer { &self.0 } }
diff --git a/src/text.rs b/src/text.rs
index c9752a4..9fe1dd4 100644
--- a/src/text.rs
+++ b/src/text.rs
@@ -17,6 +17,11 @@ pub(crate) use ::unicode_width::*;
             self.as_str().draw(to)
         }
     }
+    impl Draw<Tui> for std::sync::Arc<str> {
+        fn draw (self, to: &mut Tui) -> Usually<XYWH<u16>> {
+            self.as_ref().draw(to)
+        }
+    }
     impl Draw<Tui> for &std::sync::Arc<str> {
         fn draw (self, to: &mut Tui) -> Usually<XYWH<u16>> {
             self.as_ref().draw(to)