Sum color and length into stroke

28 files changed, 397 insertions, 228 deletions

diff --git a/macros/src/lib.rs b/macros/src/lib.rs
index 429c5b09..dbea1f83 100644
--- a/macros/src/lib.rs
+++ b/macros/src/lib.rs
@@ -155,6 +155,8 @@ fn process_const(
     let value_ty = &item.ty;
     let output_ty = if property.referenced {
         parse_quote!(&'a #value_ty)
+    } else if property.fold && property.resolve {
+        parse_quote!(<<#value_ty as eval::Resolve>::Output as eval::Fold>::Output)
     } else if property.fold {
         parse_quote!(<#value_ty as eval::Fold>::Output)
     } else if property.resolve {
@@ -190,10 +192,13 @@ fn process_const(
                 &*LAZY
             })
         };
-    } else if property.fold {
+    } else if property.resolve && property.fold {
         get = quote! {
             match values.next().cloned() {
-                Some(inner) => eval::Fold::fold(inner, Self::get(chain, values)),
+                Some(value) => eval::Fold::fold(
+                    eval::Resolve::resolve(value, chain),
+                    Self::get(chain, values),
+                ),
                 None => #default,
             }
         };
@@ -202,6 +207,13 @@ fn process_const(
             let value = values.next().cloned().unwrap_or(#default);
             eval::Resolve::resolve(value, chain)
         };
+    } else if property.fold {
+        get = quote! {
+            match values.next().cloned() {
+                Some(value) => eval::Fold::fold(value, Self::get(chain, values)),
+                None => #default,
+            }
+        };
     } else {
         get = quote! {
             values.next().copied().unwrap_or(#default)
@@ -267,8 +279,8 @@ struct Property {
     referenced: bool,
     shorthand: bool,
     variadic: bool,
-    fold: bool,
     resolve: bool,
+    fold: bool,
 }
 
 /// Parse a style property attribute.
@@ -279,8 +291,8 @@ fn parse_property(item: &mut syn::ImplItemConst) -> Result<Property> {
         referenced: false,
         shorthand: false,
         variadic: false,
-        fold: false,
         resolve: false,
+        fold: false,
     };
 
     if let Some(idx) = item
@@ -296,8 +308,8 @@ fn parse_property(item: &mut syn::ImplItemConst) -> Result<Property> {
                     "shorthand" => property.shorthand = true,
                     "referenced" => property.referenced = true,
                     "variadic" => property.variadic = true,
-                    "fold" => property.fold = true,
                     "resolve" => property.resolve = true,
+                    "fold" => property.fold = true,
                     _ => return Err(Error::new(ident.span(), "invalid attribute")),
                 },
                 TokenTree::Punct(_) => {}
@@ -314,10 +326,10 @@ fn parse_property(item: &mut syn::ImplItemConst) -> Result<Property> {
         ));
     }
 
-    if property.referenced as u8 + property.fold as u8 + property.resolve as u8 > 1 {
+    if property.referenced && (property.fold || property.resolve) {
         return Err(Error::new(
             span,
-            "referenced, fold and resolve are mutually exclusive",
+            "referenced is mutually exclusive with fold and resolve",
         ));
     }
 
diff --git a/src/eval/layout.rs b/src/eval/layout.rs
index f92a31f5..117c269a 100644
--- a/src/eval/layout.rs
+++ b/src/eval/layout.rs
@@ -7,8 +7,8 @@ use std::sync::Arc;
 
 use super::{Barrier, RawAlign, RawLength, Resolve, StyleChain};
 use crate::diag::TypResult;
-use crate::frame::{Element, Frame, Geometry, Shape, Stroke};
-use crate::geom::{Align, Length, Paint, Point, Relative, Sides, Size, Spec};
+use crate::frame::{Element, Frame, Geometry};
+use crate::geom::{Align, Length, Paint, Point, Relative, Sides, Size, Spec, Stroke};
 use crate::library::graphics::MoveNode;
 use crate::library::layout::{AlignNode, PadNode};
 use crate::util::Prehashed;
@@ -349,7 +349,7 @@ impl Layout for FillNode {
     ) -> TypResult<Vec<Arc<Frame>>> {
         let mut frames = self.child.layout(ctx, regions, styles)?;
         for frame in &mut frames {
-            let shape = Shape::filled(Geometry::Rect(frame.size), self.fill);
+            let shape = Geometry::Rect(frame.size).filled(self.fill);
             Arc::make_mut(frame).prepend(Point::zero(), Element::Shape(shape));
         }
         Ok(frames)
@@ -374,7 +374,7 @@ impl Layout for StrokeNode {
     ) -> TypResult<Vec<Arc<Frame>>> {
         let mut frames = self.child.layout(ctx, regions, styles)?;
         for frame in &mut frames {
-            let shape = Shape::stroked(Geometry::Rect(frame.size), self.stroke);
+            let shape = Geometry::Rect(frame.size).stroked(self.stroke);
             Arc::make_mut(frame).prepend(Point::zero(), Element::Shape(shape));
         }
         Ok(frames)
diff --git a/src/eval/ops.rs b/src/eval/ops.rs
index 89802949..4796e042 100644
--- a/src/eval/ops.rs
+++ b/src/eval/ops.rs
@@ -1,6 +1,6 @@
 use std::cmp::Ordering;
 
-use super::{Dynamic, RawAlign, StrExt, Value};
+use super::{Dynamic, RawAlign, RawStroke, Smart, StrExt, Value};
 use crate::diag::StrResult;
 use crate::geom::{Numeric, Spec, SpecAxis};
 use Value::*;
@@ -90,25 +90,32 @@ pub fn add(lhs: Value, rhs: Value) -> StrResult<Value> {
         (Array(a), Array(b)) => Array(a + b),
         (Dict(a), Dict(b)) => Dict(a + b),
 
-        (a, b) => {
-            if let (Dyn(a), Dyn(b)) = (&a, &b) {
-                // 1D alignments can be summed into 2D alignments.
-                if let (Some(&a), Some(&b)) =
-                    (a.downcast::<RawAlign>(), b.downcast::<RawAlign>())
-                {
-                    return if a.axis() != b.axis() {
-                        Ok(Dyn(Dynamic::new(match a.axis() {
-                            SpecAxis::Horizontal => Spec { x: a, y: b },
-                            SpecAxis::Vertical => Spec { x: b, y: a },
-                        })))
-                    } else {
-                        Err(format!("cannot add two {:?} alignments", a.axis()))
-                    };
+        (Color(color), Length(thickness)) | (Length(thickness), Color(color)) => {
+            Dyn(Dynamic::new(RawStroke {
+                paint: Smart::Custom(color.into()),
+                thickness: Smart::Custom(thickness),
+            }))
+        }
+
+        (Dyn(a), Dyn(b)) => {
+            // 1D alignments can be summed into 2D alignments.
+            if let (Some(&a), Some(&b)) =
+                (a.downcast::<RawAlign>(), b.downcast::<RawAlign>())
+            {
+                if a.axis() != b.axis() {
+                    Dyn(Dynamic::new(match a.axis() {
+                        SpecAxis::Horizontal => Spec { x: a, y: b },
+                        SpecAxis::Vertical => Spec { x: b, y: a },
+                    }))
+                } else {
+                    return Err(format!("cannot add two {:?} alignments", a.axis()));
                 }
+            } else {
+                mismatch!("cannot add {} and {}", a, b);
             }
-
-            mismatch!("cannot add {} and {}", a, b);
         }
+
+        (a, b) => mismatch!("cannot add {} and {}", a, b),
     })
 }
 
diff --git a/src/eval/raw.rs b/src/eval/raw.rs
index 622a0562..b0f46fc9 100644
--- a/src/eval/raw.rs
+++ b/src/eval/raw.rs
@@ -1,8 +1,11 @@
+use std::cmp::Ordering;
 use std::fmt::{self, Debug, Formatter};
 use std::ops::{Add, Div, Mul, Neg};
 
-use super::{Resolve, StyleChain};
-use crate::geom::{Align, Em, Length, Numeric, Relative, SpecAxis};
+use super::{Fold, Resolve, Smart, StyleChain, Value};
+use crate::geom::{
+    Align, Em, Get, Length, Numeric, Paint, Relative, Spec, SpecAxis, Stroke,
+};
 use crate::library::text::{ParNode, TextNode};
 
 /// The unresolved alignment representation.
@@ -49,6 +52,101 @@ impl Debug for RawAlign {
     }
 }
 
+dynamic! {
+    RawAlign: "alignment",
+}
+
+dynamic! {
+    Spec<RawAlign>: "2d alignment",
+}
+
+castable! {
+    Spec<Option<RawAlign>>,
+    Expected: "1d or 2d alignment",
+    @align: RawAlign => {
+        let mut aligns = Spec::default();
+        aligns.set(align.axis(), Some(*align));
+        aligns
+    },
+    @aligns: Spec<RawAlign> => aligns.map(Some),
+}
+
+/// The unresolved stroke representation.
+///
+/// In this representation, both fields are optional so that you can pass either
+/// just a paint (`red`), just a thickness (`0.1em`) or both (`2pt + red`) where
+/// this is expected.
+#[derive(Default, Copy, Clone, Eq, PartialEq, Hash)]
+pub struct RawStroke<T = RawLength> {
+    /// The stroke's paint.
+    pub paint: Smart<Paint>,
+    /// The stroke's thickness.
+    pub thickness: Smart<T>,
+}
+
+impl RawStroke<Length> {
+    /// Unpack the stroke, filling missing fields with `default`.
+    pub fn unwrap_or(self, default: Stroke) -> Stroke {
+        Stroke {
+            paint: self.paint.unwrap_or(default.paint),
+            thickness: self.thickness.unwrap_or(default.thickness),
+        }
+    }
+
+    /// Unpack the stroke, filling missing fields with the default values.
+    pub fn unwrap_or_default(self) -> Stroke {
+        self.unwrap_or(Stroke::default())
+    }
+}
+
+impl Resolve for RawStroke {
+    type Output = RawStroke<Length>;
+
+    fn resolve(self, styles: StyleChain) -> Self::Output {
+        RawStroke {
+            paint: self.paint,
+            thickness: self.thickness.resolve(styles),
+        }
+    }
+}
+
+// This faciliates RawStroke => Stroke.
+impl Fold for RawStroke<Length> {
+    type Output = Self;
+
+    fn fold(self, outer: Self::Output) -> Self::Output {
+        Self {
+            paint: self.paint.or(outer.paint),
+            thickness: self.thickness.or(outer.thickness),
+        }
+    }
+}
+
+impl<T: Debug> Debug for RawStroke<T> {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match (self.paint, &self.thickness) {
+            (Smart::Custom(paint), Smart::Custom(thickness)) => {
+                write!(f, "{thickness:?} + {paint:?}")
+            }
+            (Smart::Custom(paint), Smart::Auto) => paint.fmt(f),
+            (Smart::Auto, Smart::Custom(thickness)) => thickness.fmt(f),
+            (Smart::Auto, Smart::Auto) => f.pad("<stroke>"),
+        }
+    }
+}
+
+dynamic! {
+    RawStroke: "stroke",
+    Value::Length(thickness) => Self {
+        paint: Smart::Auto,
+        thickness: Smart::Custom(thickness),
+    },
+    Value::Color(color) => Self {
+        paint: Smart::Custom(color.into()),
+        thickness: Smart::Auto,
+    },
+}
+
 /// The unresolved length representation.
 ///
 /// Currently supports absolute and em units, but support could quite easily be
@@ -56,7 +154,7 @@ impl Debug for RawAlign {
 /// Probably, it would be a good idea to then move to an enum representation
 /// that has a small footprint and allocates for the rare case that units are
 /// mixed.
-#[derive(Default, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+#[derive(Default, Copy, Clone, Eq, PartialEq, Hash)]
 pub struct RawLength {
     /// The absolute part.
     pub length: Length,
@@ -101,6 +199,26 @@ impl Resolve for RawLength {
     }
 }
 
+impl Numeric for RawLength {
+    fn zero() -> Self {
+        Self::zero()
+    }
+
+    fn is_finite(self) -> bool {
+        self.length.is_finite() && self.em.is_finite()
+    }
+}
+
+impl PartialOrd for RawLength {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        if self.em.is_zero() && other.em.is_zero() {
+            self.length.partial_cmp(&other.length)
+        } else {
+            None
+        }
+    }
+}
+
 impl From<Length> for RawLength {
     fn from(length: Length) -> Self {
         Self { length, em: Em::zero() }
@@ -119,16 +237,6 @@ impl From<Length> for Relative<RawLength> {
     }
 }
 
-impl Numeric for RawLength {
-    fn zero() -> Self {
-        Self::zero()
-    }
-
-    fn is_finite(self) -> bool {
-        self.length.is_finite() && self.em.is_finite()
-    }
-}
-
 impl Neg for RawLength {
     type Output = Self;
 
diff --git a/src/eval/styles.rs b/src/eval/styles.rs
index 575518f5..71293f40 100644
--- a/src/eval/styles.rs
+++ b/src/eval/styles.rs
@@ -287,15 +287,6 @@ pub trait Key<'a>: 'static {
     ) -> Self::Output;
 }
 
-/// A property that is folded to determine its final value.
-pub trait Fold {
-    /// The type of the folded output.
-    type Output;
-
-    /// Fold this inner value with an outer folded value.
-    fn fold(self, outer: Self::Output) -> Self::Output;
-}
-
 /// A property that is resolved with other properties from the style chain.
 pub trait Resolve {
     /// The type of the resolved output.
@@ -354,6 +345,39 @@ where
     }
 }
 
+/// A property that is folded to determine its final value.
+pub trait Fold {
+    /// The type of the folded output.
+    type Output;
+
+    /// Fold this inner value with an outer folded value.
+    fn fold(self, outer: Self::Output) -> Self::Output;
+}
+
+impl<T> Fold for Option<T>
+where
+    T: Fold,
+    T::Output: Default,
+{
+    type Output = Option<T::Output>;
+
+    fn fold(self, outer: Self::Output) -> Self::Output {
+        self.map(|inner| inner.fold(outer.unwrap_or_default()))
+    }
+}
+
+impl<T> Fold for Smart<T>
+where
+    T: Fold,
+    T::Output: Default,
+{
+    type Output = Smart<T::Output>;
+
+    fn fold(self, outer: Self::Output) -> Self::Output {
+        self.map(|inner| inner.fold(outer.unwrap_or_default()))
+    }
+}
+
 /// A show rule recipe.
 #[derive(Clone, PartialEq, Hash)]
 struct Recipe {
@@ -472,7 +496,7 @@ impl<'a> StyleChain<'a> {
     /// Get the output value of a style property.
     ///
     /// Returns the property's default value if no map in the chain contains an
-    /// entry for it. Also takes care of folding and resolving and returns
+    /// entry for it. Also takes care of resolving and folding and returns
     /// references where applicable.
     pub fn get<K: Key<'a>>(self, key: K) -> K::Output {
         K::get(self, self.values(key))
diff --git a/src/eval/value.rs b/src/eval/value.rs
index 1851cf28..cc312c5a 100644
--- a/src/eval/value.rs
+++ b/src/eval/value.rs
@@ -2,11 +2,16 @@ use std::any::Any;
 use std::cmp::Ordering;
 use std::fmt::{self, Debug, Formatter};
 use std::hash::{Hash, Hasher};
+use std::num::NonZeroUsize;
 use std::sync::Arc;
 
-use super::{ops, Args, Array, Content, Context, Dict, Func, Layout, RawLength, StrExt};
+use super::{
+    ops, Args, Array, Content, Context, Dict, Func, Layout, LayoutNode, RawLength, StrExt,
+};
 use crate::diag::{with_alternative, At, StrResult, TypResult};
-use crate::geom::{Angle, Color, Em, Fraction, Length, Ratio, Relative, RgbaColor};
+use crate::geom::{
+    Angle, Color, Dir, Em, Fraction, Length, Paint, Ratio, Relative, RgbaColor,
+};
 use crate::library::text::RawNode;
 use crate::syntax::{Span, Spanned};
 use crate::util::EcoString;
@@ -526,7 +531,7 @@ macro_rules! castable {
         $(@$dyn_in:ident: $dyn_type:ty => $dyn_out:expr,)*
     ) => {
         impl $crate::eval::Cast<$crate::eval::Value> for $type {
-            fn is(value: &Value) -> bool {
+            fn is(value: &$crate::eval::Value) -> bool {
                 #[allow(unused_variables)]
                 match value {
                     $($pattern => true,)*
@@ -637,6 +642,14 @@ impl<T> Smart<T> {
         }
     }
 
+    /// Keeps `self` if it contains a custom value, otherwise returns `other`.
+    pub fn or(self, other: Smart<T>) -> Self {
+        match self {
+            Self::Custom(x) => Self::Custom(x),
+            Self::Auto => other,
+        }
+    }
+
     /// Returns the contained custom value or a provided default value.
     pub fn unwrap_or(self, default: T) -> T {
         match self {
@@ -655,6 +668,14 @@ impl<T> Smart<T> {
             Self::Custom(x) => x,
         }
     }
+
+    /// Returns the contained custom value or the default value.
+    pub fn unwrap_or_default(self) -> T
+    where
+        T: Default,
+    {
+        self.unwrap_or_else(T::default)
+    }
 }
 
 impl<T> Default for Smart<T> {
@@ -678,6 +699,49 @@ impl<T: Cast> Cast for Smart<T> {
     }
 }
 
+dynamic! {
+    Dir: "direction",
+}
+
+castable! {
+    usize,
+    Expected: "non-negative integer",
+    Value::Int(int) => int.try_into().map_err(|_| {
+        if int < 0 {
+            "must be at least zero"
+        } else {
+            "number too large"
+        }
+    })?,
+}
+
+castable! {
+    NonZeroUsize,
+    Expected: "positive integer",
+    Value::Int(int) => Value::Int(int)
+        .cast::<usize>()?
+        .try_into()
+        .map_err(|_| "must be positive")?,
+}
+
+castable! {
+    Paint,
+    Expected: "color",
+    Value::Color(color) => Paint::Solid(color),
+}
+
+castable! {
+    String,
+    Expected: "string",
+    Value::Str(string) => string.into(),
+}
+
+castable! {
+    LayoutNode,
+    Expected: "content",
+    Value::Content(content) => content.pack(),
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/src/export/pdf.rs b/src/export/pdf.rs
index 95d20c51..067eb277 100644
--- a/src/export/pdf.rs
+++ b/src/export/pdf.rs
@@ -16,8 +16,10 @@ use ttf_parser::{name_id, GlyphId, Tag};
 
 use super::subset::subset;
 use crate::font::{find_name, FaceId, FontStore};
-use crate::frame::{Element, Frame, Geometry, Group, Shape, Stroke, Text};
-use crate::geom::{self, Color, Em, Length, Numeric, Paint, Point, Size, Transform};
+use crate::frame::{Element, Frame, Geometry, Group, Shape, Text};
+use crate::geom::{
+    self, Color, Em, Length, Numeric, Paint, Point, Size, Stroke, Transform,
+};
 use crate::image::{Image, ImageId, ImageStore, RasterImage};
 use crate::Context;
 
diff --git a/src/export/render.rs b/src/export/render.rs
index d6f82121..c3b92d31 100644
--- a/src/export/render.rs
+++ b/src/export/render.rs
@@ -7,8 +7,8 @@ use tiny_skia as sk;
 use ttf_parser::{GlyphId, OutlineBuilder};
 use usvg::FitTo;
 
-use crate::frame::{Element, Frame, Geometry, Group, Shape, Stroke, Text};
-use crate::geom::{self, Length, Paint, PathElement, Size, Transform};
+use crate::frame::{Element, Frame, Geometry, Group, Shape, Text};
+use crate::geom::{self, Length, Paint, PathElement, Size, Stroke, Transform};
 use crate::image::{Image, RasterImage, Svg};
 use crate::Context;
 
diff --git a/src/frame.rs b/src/frame.rs
index a104c069..9613e485 100644
--- a/src/frame.rs
+++ b/src/frame.rs
@@ -5,7 +5,7 @@ use std::sync::Arc;
 
 use crate::font::FaceId;
 use crate::geom::{
-    Align, Em, Length, Numeric, Paint, Path, Point, Size, Spec, Transform,
+    Align, Em, Length, Numeric, Paint, Path, Point, Size, Spec, Stroke, Transform,
 };
 use crate::image::ImageId;
 
@@ -223,22 +223,6 @@ pub struct Shape {
     pub stroke: Option<Stroke>,
 }
 
-impl Shape {
-    /// Create a filled shape without a stroke.
-    pub fn filled(geometry: Geometry, fill: Paint) -> Self {
-        Self { geometry, fill: Some(fill), stroke: None }
-    }
-
-    /// Create a stroked shape without a fill.
-    pub fn stroked(geometry: Geometry, stroke: Stroke) -> Self {
-        Self {
-            geometry,
-            fill: None,
-            stroke: Some(stroke),
-        }
-    }
-}
-
 /// A shape's geometry.
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub enum Geometry {
@@ -252,11 +236,22 @@ pub enum Geometry {
     Path(Path),
 }
 
-/// A stroke of a geometric shape.
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
-pub struct Stroke {
-    /// The stroke's paint.
-    pub paint: Paint,
-    /// The stroke's thickness.
-    pub thickness: Length,
+impl Geometry {
+    /// Fill the geometry without a stroke.
+    pub fn filled(self, fill: Paint) -> Shape {
+        Shape {
+            geometry: self,
+            fill: Some(fill),
+            stroke: None,
+        }
+    }
+
+    /// Stroke the geometry without a fill.
+    pub fn stroked(self, stroke: Stroke) -> Shape {
+        Shape {
+            geometry: self,
+            fill: None,
+            stroke: Some(stroke),
+        }
+    }
 }
diff --git a/src/geom/paint.rs b/src/geom/paint.rs
index 3660d528..351ef443 100644
--- a/src/geom/paint.rs
+++ b/src/geom/paint.rs
@@ -5,7 +5,7 @@ use syntect::highlighting::Color as SynColor;
 use super::*;
 
 /// How a fill or stroke should be painted.
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+#[derive(Copy, Clone, Eq, PartialEq, Hash)]
 pub enum Paint {
     /// A solid color.
     Solid(Color),
@@ -20,6 +20,14 @@ where
     }
 }
 
+impl Debug for Paint {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match self {
+            Self::Solid(color) => color.fmt(f),
+        }
+    }
+}
+
 /// A color in a dynamic format.
 #[derive(Copy, Clone, Eq, PartialEq, Hash)]
 pub enum Color {
@@ -234,6 +242,24 @@ impl From<CmykColor> for Color {
     }
 }
 
+/// A stroke of a geometric shape.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+pub struct Stroke {
+    /// The stroke's paint.
+    pub paint: Paint,
+    /// The stroke's thickness.
+    pub thickness: Length,
+}
+
+impl Default for Stroke {
+    fn default() -> Self {
+        Self {
+            paint: Paint::Solid(Color::BLACK.into()),
+            thickness: Length::pt(1.0),
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/src/library/graphics/line.rs b/src/library/graphics/line.rs
index 1dd138e6..de2e4aa1 100644
--- a/src/library/graphics/line.rs
+++ b/src/library/graphics/line.rs
@@ -12,10 +12,8 @@ pub struct LineNode {
 #[node]
 impl LineNode {
     /// How to stroke the line.
-    pub const STROKE: Paint = Color::BLACK.into();
-    /// The line's thickness.
-    #[property(resolve)]
-    pub const THICKNESS: RawLength = Length::pt(1.0).into();
+    #[property(resolve, fold)]
+    pub const STROKE: RawStroke = RawStroke::default();
 
     fn construct(_: &mut Context, args: &mut Args) -> TypResult<Content> {
         let origin = args.named("origin")?.unwrap_or_default();
@@ -46,11 +44,7 @@ impl Layout for LineNode {
         regions: &Regions,
         styles: StyleChain,
     ) -> TypResult<Vec<Arc<Frame>>> {
-        let thickness = styles.get(Self::THICKNESS);
-        let stroke = Some(Stroke {
-            paint: styles.get(Self::STROKE),
-            thickness,
-        });
+        let stroke = styles.get(Self::STROKE).unwrap_or_default();
 
         let origin = self
             .origin
@@ -64,11 +58,10 @@ impl Layout for LineNode {
             .zip(regions.base)
             .map(|(l, b)| l.relative_to(b));
 
-        let geometry = Geometry::Line(delta.to_point());
-        let shape = Shape { geometry, fill: None, stroke };
-
         let target = regions.expand.select(regions.first, Size::zero());
         let mut frame = Frame::new(target);
+
+        let shape = Geometry::Line(delta.to_point()).stroked(stroke);
         frame.push(origin.to_point(), Element::Shape(shape));
 
         Ok(vec![Arc::new(frame)])
diff --git a/src/library/graphics/shape.rs b/src/library/graphics/shape.rs
index ec6f735b..a159a3af 100644
--- a/src/library/graphics/shape.rs
+++ b/src/library/graphics/shape.rs
@@ -24,10 +24,8 @@ impl<const S: ShapeKind> ShapeNode<S> {
     /// How to fill the shape.
     pub const FILL: Option<Paint> = None;
     /// How to stroke the shape.
-    pub const STROKE: Smart<Option<Paint>> = Smart::Auto;
-    /// The stroke's thickness.
-    #[property(resolve)]
-    pub const THICKNESS: RawLength = Length::pt(1.0).into();
+    #[property(resolve, fold)]
+    pub const STROKE: Smart<Option<RawStroke>> = Smart::Auto;
     /// How much to pad the shape's content.
     pub const PADDING: Relative<RawLength> = Relative::zero();
 
@@ -115,11 +113,10 @@ impl<const S: ShapeKind> Layout for ShapeNode<S> {
 
         // Add fill and/or stroke.
         let fill = styles.get(Self::FILL);
-        let thickness = styles.get(Self::THICKNESS);
-        let stroke = styles
-            .get(Self::STROKE)
-            .unwrap_or(fill.is_none().then(|| Color::BLACK.into()))
-            .map(|paint| Stroke { paint, thickness });
+        let stroke = match styles.get(Self::STROKE) {
+            Smart::Auto => fill.is_none().then(Stroke::default),
+            Smart::Custom(stroke) => stroke.map(RawStroke::unwrap_or_default),
+        };
 
         if fill.is_some() || stroke.is_some() {
             let geometry = if is_round(S) {
diff --git a/src/library/mod.rs b/src/library/mod.rs
index a5f0b50c..0034b581 100644
--- a/src/library/mod.rs
+++ b/src/library/mod.rs
@@ -124,65 +124,3 @@ pub fn new() -> Scope {
 
     std
 }
-
-dynamic! {
-    Dir: "direction",
-}
-
-dynamic! {
-    RawAlign: "alignment",
-}
-
-dynamic! {
-    Spec<RawAlign>: "2d alignment",
-}
-
-castable! {
-    Spec<Option<RawAlign>>,
-    Expected: "1d or 2d alignment",
-    @align: RawAlign => {
-        let mut aligns = Spec::default();
-        aligns.set(align.axis(), Some(*align));
-        aligns
-    },
-    @aligns: Spec<RawAlign> => aligns.map(Some),
-}
-
-castable! {
-    usize,
-    Expected: "non-negative integer",
-    Value::Int(int) => int.try_into().map_err(|_| {
-        if int < 0 {
-            "must be at least zero"
-        } else {
-            "number too large"
-        }
-    })?,
-}
-
-castable! {
-    NonZeroUsize,
-    Expected: "positive integer",
-    Value::Int(int) => Value::Int(int)
-        .cast::<usize>()?
-        .try_into()
-        .map_err(|_| "must be positive")?,
-}
-
-castable! {
-    Paint,
-    Expected: "color",
-    Value::Color(color) => Paint::Solid(color),
-}
-
-castable! {
-    String,
-    Expected: "string",
-    Value::Str(string) => string.into(),
-}
-
-castable! {
-    LayoutNode,
-    Expected: "content",
-    Value::Content(content) => content.pack(),
-}
diff --git a/src/library/prelude.rs b/src/library/prelude.rs
index d74a5d85..a1ebe6ef 100644
--- a/src/library/prelude.rs
+++ b/src/library/prelude.rs
@@ -10,7 +10,7 @@ pub use typst_macros::node;
 pub use crate::diag::{with_alternative, At, Error, StrResult, TypError, TypResult};
 pub use crate::eval::{
     Arg, Args, Array, Cast, Content, Dict, Fold, Func, Key, Layout, LayoutNode, Merge,
-    Node, RawAlign, RawLength, Regions, Resolve, Scope, Show, ShowNode, Smart,
+    Node, RawAlign, RawLength, RawStroke, Regions, Resolve, Scope, Show, ShowNode, Smart,
     StyleChain, StyleMap, StyleVec, Value,
 };
 pub use crate::frame::*;
diff --git a/src/library/structure/table.rs b/src/library/structure/table.rs
index d0ab0716..40f25749 100644
--- a/src/library/structure/table.rs
+++ b/src/library/structure/table.rs
@@ -19,10 +19,8 @@ impl TableNode {
     /// The secondary cell fill color.
     pub const SECONDARY: Option<Paint> = None;
     /// How to stroke the cells.
-    pub const STROKE: Option<Paint> = Some(Color::BLACK.into());
-    /// The stroke's thickness.
-    #[property(resolve)]
-    pub const THICKNESS: RawLength = Length::pt(1.0).into();
+    #[property(resolve, fold)]
+    pub const STROKE: Option<RawStroke> = Some(RawStroke::default());
     /// How much to pad the cells's content.
     pub const PADDING: Relative<RawLength> = Length::pt(5.0).into();
 
@@ -48,7 +46,6 @@ impl TableNode {
         styles.set_opt(Self::PRIMARY, args.named("primary")?.or(fill));
         styles.set_opt(Self::SECONDARY, args.named("secondary")?.or(fill));
         styles.set_opt(Self::STROKE, args.named("stroke")?);
-        styles.set_opt(Self::THICKNESS, args.named("thickness")?);
         styles.set_opt(Self::PADDING, args.named("padding")?);
         Ok(styles)
     }
@@ -63,8 +60,7 @@ impl Show for TableNode {
 
         let primary = styles.get(Self::PRIMARY);
         let secondary = styles.get(Self::SECONDARY);
-        let thickness = styles.get(Self::THICKNESS);
-        let stroke = styles.get(Self::STROKE).map(|paint| Stroke { paint, thickness });
+        let stroke = styles.get(Self::STROKE).map(RawStroke::unwrap_or_default);
         let padding = styles.get(Self::PADDING);
 
         let cols = self.tracks.x.len().max(1);
diff --git a/src/library/text/deco.rs b/src/library/text/deco.rs
index f5ed4744..b8a0b3cb 100644
--- a/src/library/text/deco.rs
+++ b/src/library/text/deco.rs
@@ -20,12 +20,10 @@ pub type OverlineNode = DecoNode<OVERLINE>;
 
 #[node(showable)]
 impl<const L: DecoLine> DecoNode<L> {
-    /// Stroke color of the line, defaults to the text color if `None`.
-    #[property(shorthand)]
-    pub const STROKE: Option<Paint> = None;
-    /// Thickness of the line's strokes, read from the font tables if `auto`.
-    #[property(shorthand, resolve)]
-    pub const THICKNESS: Smart<RawLength> = Smart::Auto;
+    /// How to stroke the line. The text color and thickness read from the font
+    /// tables if `auto`.
+    #[property(shorthand, resolve, fold)]
+    pub const STROKE: Smart<RawStroke> = Smart::Auto;
     /// Position of the line relative to the baseline, read from the font tables
     /// if `auto`.
     #[property(resolve)]
@@ -49,8 +47,7 @@ impl<const L: DecoLine> Show for DecoNode<L> {
             .unwrap_or_else(|| {
                 self.0.clone().styled(TextNode::DECO, Decoration {
                     line: L,
-                    stroke: styles.get(Self::STROKE),
-                    thickness: styles.get(Self::THICKNESS),
+                    stroke: styles.get(Self::STROKE).unwrap_or_default(),
                     offset: styles.get(Self::OFFSET),
                     extent: styles.get(Self::EXTENT),
                     evade: styles.get(Self::EVADE),
@@ -65,8 +62,7 @@ impl<const L: DecoLine> Show for DecoNode<L> {
 #[derive(Debug, Clone, Eq, PartialEq, Hash)]
 pub struct Decoration {
     pub line: DecoLine,
-    pub stroke: Option<Paint>,
-    pub thickness: Smart<Length>,
+    pub stroke: RawStroke<Length>,
     pub offset: Smart<Length>,
     pub extent: Length,
     pub evade: bool,
@@ -103,11 +99,10 @@ pub fn decorate(
 
     let evade = deco.evade && deco.line != STRIKETHROUGH;
     let offset = deco.offset.unwrap_or(-metrics.position.at(text.size));
-
-    let stroke = Stroke {
-        paint: deco.stroke.unwrap_or(text.fill),
-        thickness: deco.thickness.unwrap_or(metrics.thickness.at(text.size)),
-    };
+    let stroke = deco.stroke.unwrap_or(Stroke {
+        paint: text.fill,
+        thickness: metrics.thickness.at(text.size),
+    });
 
     let gap_padding = 0.08 * text.size;
     let min_width = 0.162 * text.size;
@@ -120,7 +115,7 @@ pub fn decorate(
         let target = Point::new(to - from, Length::zero());
 
         if target.x >= min_width || !evade {
-            let shape = Shape::stroked(Geometry::Line(target), stroke);
+            let shape = Geometry::Line(target).stroked(stroke);
             frame.push(origin, Element::Shape(shape));
         }
     };
diff --git a/tests/ref/code/repr.png b/tests/ref/code/repr.png
index 822b096d..4474149a 100644
--- a/tests/ref/code/repr.png
+++ b/tests/ref/code/repr.png
diff --git a/tests/ref/graphics/shape-fill-stroke.png b/tests/ref/graphics/shape-fill-stroke.png
index 12fcbd55..f2278c88 100644
--- a/tests/ref/graphics/shape-fill-stroke.png
+++ b/tests/ref/graphics/shape-fill-stroke.png
diff --git a/tests/ref/structure/table.png b/tests/ref/structure/table.png
index bc70d548..f50f613b 100644
--- a/tests/ref/structure/table.png
+++ b/tests/ref/structure/table.png
diff --git a/tests/ref/text/deco.png b/tests/ref/text/deco.png
index 684532a1..94bd8a38 100644
--- a/tests/ref/text/deco.png
+++ b/tests/ref/text/deco.png
diff --git a/tests/typ/code/repr.typ b/tests/typ/code/repr.typ
index f766ee7e..8742f413 100644
--- a/tests/typ/code/repr.typ
+++ b/tests/typ/code/repr.typ
@@ -1,17 +1,8 @@
 // Test representation of values in the document.
 
 ---
-// Variables.
-#let name = "Typst"
-#let ke-bab = "Kebab!"
-#let α = "Alpha"
-
-{name} \
-{ke-bab} \
-{α}
-
----
 // Literal values.
+{auto} \
 {none} (empty) \
 {true} \
 {false}
@@ -27,29 +18,30 @@
 {4.5cm} \
 {12e1pt} \
 {2.5rad} \
-{45deg}
+{45deg} \
+{1.7em} \
+{1cm + 0em} \
+{2em + 10pt} \
+{2.3fr}
 
 ---
 // Colors.
-#rgb("f7a20500")
+#rgb("f7a20500") \
+{2pt + rgb("f7a20500")}
 
 ---
 // Strings and escaping.
-{"hi"} \
-{"a\n[]\"\u{1F680}string"}
+#repr("hi") \
+#repr("a\n[]\"\u{1F680}string")
 
 ---
 // Content.
-{[*{"H" + "i"} there*]}
+#repr[*{"H" + "i"} there*]
 
 ---
 // Functions
 #let f(x) = x
 
-{rect} \
+{() => none} \
 {f} \
-{() => none}
-
----
-// When using the `repr` function it's not in monospace.
-#repr(23deg)
+{rect}
diff --git a/tests/typ/graphics/line.typ b/tests/typ/graphics/line.typ
index 050ce05c..97dcb5cf 100644
--- a/tests/typ/graphics/line.typ
+++ b/tests/typ/graphics/line.typ
@@ -37,7 +37,7 @@
   ]
 ]
 
-#align(center, grid(columns: (1fr,) * 3, ..((star(20pt, thickness: .5pt),) * 9)))
+#align(center, grid(columns: (1fr,) * 3, ..((star(20pt, stroke: 0.5pt),) * 9)))
 
 ---
 // Test errors.
diff --git a/tests/typ/graphics/shape-circle.typ b/tests/typ/graphics/shape-circle.typ
index 4b978e86..dc1e3f24 100644
--- a/tests/typ/graphics/shape-circle.typ
+++ b/tests/typ/graphics/shape-circle.typ
@@ -9,7 +9,7 @@
 // Test auto sizing.
 
 Auto-sized circle. \
-#circle(fill: rgb("eb5278"), stroke: black, thickness: 2pt,
+#circle(fill: rgb("eb5278"), stroke: 2pt + black,
   align(center + horizon)[But, soft!]
 )
 
diff --git a/tests/typ/graphics/shape-ellipse.typ b/tests/typ/graphics/shape-ellipse.typ
index 154144c4..995eabb9 100644
--- a/tests/typ/graphics/shape-ellipse.typ
+++ b/tests/typ/graphics/shape-ellipse.typ
@@ -17,7 +17,7 @@ Rect in ellipse in fixed rect. \
 )
 
 Auto-sized ellipse. \
-#ellipse(fill: conifer, stroke: forest, thickness: 3pt, padding: 3pt)[
+#ellipse(fill: conifer, stroke: 3pt + forest, padding: 3pt)[
   #set text(8pt)
   But, soft! what light through yonder window breaks?
 ]
diff --git a/tests/typ/graphics/shape-fill-stroke.typ b/tests/typ/graphics/shape-fill-stroke.typ
index dd5b9ee8..c09cb065 100644
--- a/tests/typ/graphics/shape-fill-stroke.typ
+++ b/tests/typ/graphics/shape-fill-stroke.typ
@@ -6,15 +6,15 @@
   variant(stroke: none),
   variant(),
   variant(fill: none),
-  variant(thickness: 2pt),
+  variant(stroke: 2pt),
   variant(stroke: eastern),
-  variant(stroke: eastern, thickness: 2pt),
+  variant(stroke: eastern + 2pt),
   variant(fill: eastern),
   variant(fill: eastern, stroke: none),
-  variant(fill: forest, stroke: none, thickness: 2pt),
+  variant(fill: forest, stroke: none),
   variant(fill: forest, stroke: conifer),
-  variant(fill: forest, stroke: black, thickness: 2pt),
-  variant(fill: forest, stroke: conifer, thickness: 2pt),
+  variant(fill: forest, stroke: black + 2pt),
+  variant(fill: forest, stroke: conifer + 2pt),
 ) {
   (align(horizon)[{i + 1}.], item, [])
 }
@@ -24,3 +24,17 @@
   gutter: 5pt,
   ..items,
 )
+
+---
+// Test stroke folding.
+#let sq = square.with(size: 10pt)
+
+#set square(stroke: none)
+#sq()
+#set square(stroke: auto)
+#sq()
+#sq(fill: teal)
+#sq(stroke: 2pt)
+#sq(stroke: blue)
+#sq(fill: teal, stroke: blue)
+#sq(fill: teal, stroke: 2pt + blue)
diff --git a/tests/typ/graphics/shape-rect.typ b/tests/typ/graphics/shape-rect.typ
index add39b80..e035fc91 100644
--- a/tests/typ/graphics/shape-rect.typ
+++ b/tests/typ/graphics/shape-rect.typ
@@ -14,8 +14,7 @@
 #block(rect(
   height: 15pt,
   fill: rgb("46b3c2"),
-  stroke: rgb("234994"),
-  thickness: 2pt,
+  stroke: 2pt + rgb("234994"),
 ))
 
 // Fixed width, text height.
diff --git a/tests/typ/structure/table.typ b/tests/typ/structure/table.typ
index 0372951c..57b71ede 100644
--- a/tests/typ/structure/table.typ
+++ b/tests/typ/structure/table.typ
@@ -1,13 +1,18 @@
+// Test tables.
+
+---
 #set page(height: 70pt)
 #set table(primary: rgb("aaa"), secondary: none)
 
 #table(
   columns: (1fr,) * 3,
-  stroke: rgb("333"),
-  thickness: 2pt,
+  stroke: 2pt + rgb("333"),
   [A], [B], [C], [], [], [D \ E \ F \ \ \ G], [H],
 )
 
 ---
+#table(columns: 3, stroke: none, fill: green, [A], [B], [C])
+
+---
 // Ref: false
 #table()
diff --git a/tests/typ/text/deco.typ b/tests/typ/text/deco.typ
index 071208ac..5e9de5b3 100644
--- a/tests/typ/text/deco.typ
+++ b/tests/typ/text/deco.typ
@@ -20,12 +20,14 @@
 
 ---
 #let redact = strike.with(10pt, extent: 0.05em)
-#let highlight = strike.with(
-  stroke: rgb("abcdef88"),
-  thickness: 10pt,
-  extent: 0.05em,
-)
+#let highlight = strike.with(stroke: 10pt + rgb("abcdef88"), extent: 0.05em)
 
 // Abuse thickness and transparency for redacting and highlighting stuff.
 Sometimes, we work #redact[in secret].
 There might be #highlight[redacted] things.
+ underline()
+
+---
+// Test stroke folding.
+#set underline(stroke: 2pt, offset: 2pt)
+#underline(text(red, [DANGER!]))