diff --git a/examples/mode_01.rs b/examples/mode_01.rs
index 39031c4..0ad5241 100644
--- a/examples/mode_01.rs
+++ b/examples/mode_01.rs
@@ -44,6 +44,14 @@ impl Interpret<Tui, Color> for State {
         }
     }
 }
+fn try_to_u8 (src: Perhaps<&str>) -> Perhaps<u8> {
+    use std::str::FromStr;
+    if let Some(src) = src? {
+        Ok(Some(u8::from_str(src)?))
+    } else {
+        Ok(None)
+    }
+}
 impl Interpret<Tui, Option<XYWH<u16>>> for State {
     fn interpret_word (&self, to: &mut Tui, sym: &impl Language) -> Perhaps<XYWH<u16>> {
         match sym.src()? {
diff --git a/src/draw.rs b/src/draw.rs
index 36690f8..9d27ad3 100644
--- a/src/draw.rs
+++ b/src/draw.rs
@@ -13,16 +13,20 @@ use crate::*;
 /// }
 /// impl Screen for TestOut {
 ///     type Unit = u16;
-///     fn show (&mut self, _: impl Draw<Self>) -> Perhaps<XYWH<u16>>
-///         { println!("placed"); Ok(None) }
-///     fn area (&self) -> XYWH<Self::Unit>
-///         { Default::default() }
+///     fn show (&mut self, _: impl Draw<Self>) -> Perhaps<XYWH<u16>> {
+///         println!("placed");
+///         Ok(None)
+///     }
+///     fn area (&self) -> XYWH<Self::Unit> {
+///         Default::default()
+///     }
 ///     fn clip <T> (
 ///         &mut self,
 ///         area: impl Into<Option<XYWH<u16>>>,
 ///         draw: impl FnOnce(&mut Self)->T
-///     ) -> T
-///         { draw(self }
+///     ) -> T {
+///         draw(self)
+///     }
 /// }
 ///
 /// impl_draw!(|self: String, to: TestOut|{
diff --git a/src/draw/layout.rs b/src/draw/layout.rs
index 9074158..ecc1316 100644
--- a/src/draw/layout.rs
+++ b/src/draw/layout.rs
@@ -160,10 +160,14 @@ pub trait Layout<S: Screen>: Draw<S> + Sized {
 /// Use whole drawing area along one or both axes.
 ///
 /// ```
-/// use tengri::Layout;
-/// let _ = "".full_w();
-/// let _ = "".full_h();
-/// let _ = "".full_wh();
+/// # fn doctest_layout_full () -> Result<(), Box<dyn std::error::Error>> {
+/// use tengri::{Layout, Draw, XYWH};
+/// let area = XYWH(0u16, 0, 80, 25);
+/// assert_eq!("1".layout(area)?,           Some(XYWH(0u16, 0,  1,  1)));
+/// assert_eq!("1".full_w().layout(area)?,  Some(XYWH(0u16, 0, 80,  1)));
+/// assert_eq!("1".full_h().layout(area)?,  Some(XYWH(0u16, 0,  1, 25)));
+/// assert_eq!("1".full_wh().layout(area)?, Some(XYWH(0u16, 0, 80, 25)));
+/// # Ok(()) }
 /// ```
 pub enum Full<T: Screen, I: Draw<T>> {
     __(PhantomData<T>),
@@ -171,7 +175,6 @@ pub enum Full<T: Screen, I: Draw<T>> {
     H(I),
     WH(I),
 }
-
 impl_draw!(<T: Screen, I: Draw<T>,>|self: Full<T, I>, to: T|{
     let XYWH(x0, y0, w0, h0) = to.area();
     match self {
@@ -197,10 +200,14 @@ impl_draw!(<T: Screen, I: Draw<T>,>|self: Full<T, I>, to: T|{
 /// Move content in the positive direction of one or both axes.
 ///
 /// ```
-/// use tengri::Layout;
-/// let _ = "".push_x(1);
-/// let _ = "".push_y(1);
-/// let _ = "".push_xy(1, 1);
+/// # fn doctest_layout_push () -> Result<(), Box<dyn std::error::Error>> {
+/// use tengri::{Layout, Draw, XYWH};
+/// let area = XYWH(0u16, 0, 80, 25);
+/// assert_eq!("1".layout(area)?,               Some(XYWH(0u16, 0, 1, 1)));
+/// assert_eq!("1".push_x(1).layout(area)?,     Some(XYWH(1u16, 0, 1, 1)));
+/// assert_eq!("1".push_y(1).layout(area)?,     Some(XYWH(0u16, 1, 1, 1)));
+/// assert_eq!("1".push_xy(1, 1).layout(area)?, Some(XYWH(1u16, 1, 1, 1)));
+/// # Ok(()) }
 /// ```
 pub enum Push<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>> {
     __(PhantomData<T>),
@@ -208,7 +215,6 @@ pub enum Push<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>> {
     Y(I, X),
     XY(I, X, X),
 }
-
 impl_draw!(<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>,>|self: Push<T, I, X>, to: T|{
     match self {
         Self::__(_) => unreachable!(),
@@ -234,10 +240,14 @@ impl_draw!(<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>,>|self: Push<T, I, X
 /// Move content in the negative direction of one or both axes.
 ///
 /// ```
-/// use tengri::Layout;
-/// let _ = "".pull_x(1);
-/// let _ = "".pull_y(1);
-/// let _ = "".pull_xy(1, 1);
+/// # fn doctest_layout_pull () -> Result<(), Box<dyn std::error::Error>> {
+/// use tengri::{Layout, Draw, XYWH};
+/// let area = XYWH(1u16, 1, 80, 25);
+/// assert_eq!("1".layout(area)?,               Some(XYWH(0u16, 0, 1, 1)));
+/// assert_eq!("1".pull_x(1).layout(area)?,     Some(XYWH(0u16, 1, 1, 1)));
+/// assert_eq!("1".pull_y(1).layout(area)?,     Some(XYWH(1u16, 0, 1, 1)));
+/// assert_eq!("1".pull_xy(1, 1).layout(area)?, Some(XYWH(0u16, 0, 1, 1)));
+/// # }
 /// ```
 pub enum Pull<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>> {
     __(PhantomData<T>),
@@ -245,7 +255,6 @@ pub enum Pull<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>> {
     Y(I, X),
     XY(I, X, X),
 }
-
 impl_draw!(<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>,>|self: Pull<T, I, X>, _to: T|{
     todo!()
 });
@@ -253,10 +262,14 @@ impl_draw!(<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>,>|self: Pull<T, I, X
 /// Only draw content if area is above a certain size.
 ///
 /// ```
-/// use tengri::Layout;
-/// let _ = "".min_w(1);
-/// let _ = "".min_h(1);
-/// let _ = "".min_wh(1, 1);
+/// # fn doctest_layout_min () -> Result<(), Box<dyn std::error::Error>> {
+/// use tengri::{Layout, Draw, XYWH};
+/// let area = XYWH(1u16, 1, 80, 25);
+/// assert_eq!("1".min_w(5).layout(area)?,      Some(XYWH(1u16, 1, 5, 1)));
+/// assert_eq!("1".min_h(5).layout(area)?,      Some(XYWH(1u16, 1, 1, 5)));
+/// assert_eq!("1".min_wh(5, 5).layout(area)?,  Some(XYWH(1u16, 1, 5, 5)));
+/// assert_eq!("123456".min_w(5).layout(area)?, Some(XYWH(1u16, 1, 6, 1)));
+/// # Ok(()) }
 /// ```
 pub enum Min<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>> {
     __(PhantomData<T>),
@@ -264,7 +277,6 @@ pub enum Min<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>> {
     H(I, X),
     WH(I, X, X),
 }
-
 impl_draw!(<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>,>|self: Min<T, I, X>, _to: T|{
     todo!()
 });
@@ -272,10 +284,13 @@ impl_draw!(<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>,>|self: Min<T, I, X>
 /// Set maximum size of of drawing area.
 ///
 /// ```
-/// use tengri::Layout;
-/// let _ = "".max_w(1);
-/// let _ = "".max_h(1);
-/// let _ = "".max_wh(1, 1);
+/// # fn doctest_layout_max () -> Result<(), Box<dyn std::error::Error>> {
+/// use tengri::{Layout, Draw, XYWH};
+/// let area = XYWH(1u16, 1, 80, 25);
+/// assert_eq!("12345".max_w(1).layout(area)?,     Some(XYWH(1u16, 1, 1, 1)));
+/// assert_eq!("12345".max_h(1).layout(area)?,     Some(XYWH(1u16, 1, 1, 1)));
+/// assert_eq!("12345".max_wh(1, 1).layout(area)?, Some(XYWH(1u16, 1, 5, 1)));
+/// # Ok(()) }
 /// ```
 pub enum Max<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>> {
     __(PhantomData<T>),
@@ -283,7 +298,6 @@ pub enum Max<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>> {
     H(I, X),
     WH(I, X, X),
 }
-
 impl_draw!(<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>,>|self: Max<T, I, X>, to: T|{
     let area: XYWH<T::Unit> = to.area();
     let (item, area) = match self {
@@ -318,7 +332,6 @@ pub enum Exact<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>> {
     H(I, X),
     WH(I, X, X),
 }
-
 impl_draw!(<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>,>|self: Exact<T, I, X>, to: T|{
     let area: XYWH<T::Unit> = to.area();
     let (item, area) = match self {
@@ -347,13 +360,11 @@ pub enum Pad<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>> {
     H(I, X),
     WH(I, X, X),
 }
-
 impl_draw!(<T: Screen, I: Draw<T>, X: Into<Option<T::Unit>>,>|self: Pad<T, I, X>, _to: T|{
     todo!()
 });
 
 pub struct Align<T>(Option<Azimuth>, T);
-
 impl_draw!(<S: Screen, T: Draw<S>,>|self: Align<T>, to: S|{
     use Azimuth::*;
     let XYWH(x0, y0, w0, h0) = to.area();
@@ -405,13 +416,11 @@ pub struct Area<S: Screen, T: Draw<S>>(
     pub Option<XYWH<S::Unit>>,
     pub T
 );
-
 impl_draw!(<S: Screen, T: Draw<S>,>|self: Area<S, T>, to: S|{
     to.clip(self.0, |to|self.1.draw(to))
 });
 
 pub struct Origin<T>(Option<Azimuth>, T);
-
 impl_draw!(<S: Screen, T: Draw<S>,>|self: Origin<T>, _to: S|{
     todo!()
 });