Refactor

13 files changed, 149 insertions, 139 deletions

diff --git a/src/eval/class.rs b/src/eval/class.rs
index 15e1f249..5682cb4d 100644
--- a/src/eval/class.rs
+++ b/src/eval/class.rs
@@ -84,7 +84,7 @@ impl Class {
 impl Debug for Class {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
         f.write_str("<class ")?;
-        f.write_str(&self.0.name)?;
+        f.write_str(self.name())?;
         f.write_char('>')
     }
 }
diff --git a/src/eval/styles.rs b/src/eval/styles.rs
index f8413feb..d7c17b92 100644
--- a/src/eval/styles.rs
+++ b/src/eval/styles.rs
@@ -70,8 +70,8 @@ impl StyleMap {
     /// `outer`. The ones from `self` take precedence over the ones from
     /// `outer`. For folded properties `self` contributes the inner value.
     pub fn chain<'a>(&'a self, outer: &'a StyleChain<'a>) -> StyleChain<'a> {
+        // No need to chain an empty map.
         if self.is_empty() {
-            // No need to chain an empty map.
             *outer
         } else {
             StyleChain { inner: self, outer: Some(outer) }
@@ -86,12 +86,12 @@ impl StyleMap {
     /// style maps, whereas `chain` would be used during layouting to combine
     /// immutable style maps from different levels of the hierarchy.
     pub fn apply(&mut self, outer: &Self) {
-        'outer: for outer in &outer.0 {
-            for inner in &mut self.0 {
-                if inner.style_id() == outer.style_id() {
-                    inner.fold(outer);
-                    continue 'outer;
-                }
+        for outer in &outer.0 {
+            if let Some(inner) =
+                self.0.iter_mut().find(|inner| inner.style_id() == outer.style_id())
+            {
+                *inner = inner.fold(outer);
+                continue;
             }
 
             self.0.push(outer.clone());
@@ -158,16 +158,16 @@ impl<'a> StyleChain<'a> {
 
     /// Get the (folded) value of a copyable style property.
     ///
+    /// This is the method you should reach for first. If it doesn't work
+    /// because your property is not copyable, use `get_ref`. If that doesn't
+    /// work either because your property needs folding, use `get_cloned`.
+    ///
     /// Returns the property's default value if no map in the chain contains an
     /// entry for it.
-    pub fn get<P>(self, key: P) -> P::Value
+    pub fn get<P: Property>(self, key: P) -> P::Value
     where
-        P: Property,
         P::Value: Copy,
     {
-        // This exists separately to `get_cloned` for `Copy` types so that
-        // people don't just naively use `get` / `get_cloned` where they should
-        // use `get_ref`.
         self.get_cloned(key)
     }
 
@@ -177,13 +177,13 @@ impl<'a> StyleChain<'a> {
     /// Prefer `get` if possible or resort to `get_cloned` for non-`Copy`
     /// properties that need folding.
     ///
-    /// Returns a reference to the property's default value if no map in the
-    /// chain contains an entry for it.
-    pub fn get_ref<P>(self, key: P) -> &'a P::Value
+    /// Returns a lazily-initialized reference to the property's default value
+    /// if no map in the chain contains an entry for it.
+    pub fn get_ref<P: Property>(self, key: P) -> &'a P::Value
     where
-        P: Property + Nonfolding,
+        P: Nonfolding,
     {
-        if let Some(value) = self.get_locally(key) {
+        if let Some(value) = self.find(key) {
             value
         } else if let Some(outer) = self.outer {
             outer.get_ref(key)
@@ -197,11 +197,11 @@ impl<'a> StyleChain<'a> {
     /// While this works for all properties, you should prefer `get` or
     /// `get_ref` where possible. This is only needed for non-`Copy` properties
     /// that need folding.
-    pub fn get_cloned<P>(self, key: P) -> P::Value
-    where
-        P: Property,
-    {
-        if let Some(value) = self.get_locally(key).cloned() {
+    ///
+    /// Returns the property's default value if no map in the chain contains an
+    /// entry for it.
+    pub fn get_cloned<P: Property>(self, key: P) -> P::Value {
+        if let Some(value) = self.find(key).cloned() {
             if P::FOLDABLE {
                 if let Some(outer) = self.outer {
                     P::fold(value, outer.get_cloned(key))
@@ -218,8 +218,8 @@ impl<'a> StyleChain<'a> {
         }
     }
 
-    /// Find a property directly in the most local map.
-    fn get_locally<P: Property>(&self, _: P) -> Option<&'a P::Value> {
+    /// Find a property directly in the localmost map.
+    fn find<P: Property>(self, _: P) -> Option<&'a P::Value> {
         self.inner
             .0
             .iter()
@@ -309,8 +309,8 @@ impl Entry {
         self.0.as_any().downcast_ref()
     }
 
-    fn fold(&mut self, outer: &Self) {
-        *self = self.0.fold(outer);
+    fn fold(&self, outer: &Self) -> Self {
+        self.0.fold(outer)
     }
 }
 
diff --git a/src/geom/spec.rs b/src/geom/spec.rs
index 40d7386b..cf75f42d 100644
--- a/src/geom/spec.rs
+++ b/src/geom/spec.rs
@@ -85,10 +85,19 @@ impl<T> Spec<T> {
     }
 }
 
-impl<T> Spec<T>
-where
-    T: Ord,
-{
+impl<T: Default> Spec<T> {
+    /// Create a new instance with y set to its default value.
+    pub fn with_x(x: T) -> Self {
+        Self { x, y: T::default() }
+    }
+
+    /// Create a new instance with x set to its default value.
+    pub fn with_y(y: T) -> Self {
+        Self { x: T::default(), y }
+    }
+}
+
+impl<T: Ord> Spec<T> {
     /// The component-wise minimum of this and another instance.
     pub fn min(self, other: Self) -> Self {
         Self {
diff --git a/src/library/align.rs b/src/library/align.rs
index 32735244..e8dfabb1 100644
--- a/src/library/align.rs
+++ b/src/library/align.rs
@@ -7,33 +7,7 @@ use super::ParNode;
 pub fn align(_: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
     let aligns: Spec<_> = args.find().unwrap_or_default();
     let body: PackedNode = args.expect("body")?;
-
-    let mut styles = StyleMap::new();
-    if let Some(align) = aligns.x {
-        styles.set(ParNode::ALIGN, align);
-    }
-
-    Ok(Value::block(body.styled(styles).aligned(aligns)))
-}
-
-dynamic! {
-    Align: "alignment",
-}
-
-dynamic! {
-    Spec<Align>: "2d alignment",
-}
-
-castable! {
-    Spec<Option<Align>>,
-    Expected: "1d or 2d alignment",
-    @align: Align => {
-        let mut aligns = Spec::default();
-        aligns.set(align.axis(), Some(*align));
-        aligns
-    },
-    @aligns: Spec<Align> => aligns.map(Some),
-
+    Ok(Value::block(body.aligned(aligns)))
 }
 
 /// A node that aligns its child.
@@ -56,8 +30,14 @@ impl Layout for AlignNode {
         let mut pod = regions.clone();
         pod.expand &= self.aligns.map_is_none();
 
+        // Align paragraphs inside the child.
+        let mut passed = StyleMap::new();
+        if let Some(align) = self.aligns.x {
+            passed.set(ParNode::ALIGN, align);
+        }
+
         // Layout the child.
-        let mut frames = self.child.layout(ctx, &pod, styles);
+        let mut frames = self.child.layout(ctx, &pod, passed.chain(&styles));
 
         for ((current, base), Constrained { item: frame, cts }) in
             regions.iter().zip(&mut frames)
@@ -78,3 +58,23 @@ impl Layout for AlignNode {
         frames
     }
 }
+
+dynamic! {
+    Align: "alignment",
+}
+
+dynamic! {
+    Spec<Align>: "2d alignment",
+}
+
+castable! {
+    Spec<Option<Align>>,
+    Expected: "1d or 2d alignment",
+    @align: Align => {
+        let mut aligns = Spec::default();
+        aligns.set(align.axis(), Some(*align));
+        aligns
+    },
+    @aligns: Spec<Align> => aligns.map(Some),
+
+}
diff --git a/src/library/columns.rs b/src/library/columns.rs
index 17ae6058..ce02b508 100644
--- a/src/library/columns.rs
+++ b/src/library/columns.rs
@@ -98,7 +98,7 @@ impl Layout for ColumnsNode {
             // case, the frame is first created with zero height and then
             // resized.
             let height = if regions.expand.y { current.y } else { Length::zero() };
-            let mut output = Frame::new(Spec::new(regions.current.x, height));
+            let mut output = Frame::new(Size::new(regions.current.x, height));
             let mut cursor = Length::zero();
 
             for _ in 0 .. columns {
diff --git a/src/library/heading.rs b/src/library/heading.rs
index 111472f4..3591ea0c 100644
--- a/src/library/heading.rs
+++ b/src/library/heading.rs
@@ -6,18 +6,18 @@ use super::{FontFamily, TextNode};
 /// A section heading.
 #[derive(Debug, Hash)]
 pub struct HeadingNode {
-    /// The node that produces the heading's contents.
-    pub child: PackedNode,
     /// The logical nesting depth of the section, starting from one. In the
     /// default style, this controls the text size of the heading.
     pub level: usize,
+    /// The node that produces the heading's contents.
+    pub child: PackedNode,
 }
 
 #[properties]
 impl HeadingNode {
     /// The heading's font family.
     pub const FAMILY: Smart<FontFamily> = Smart::Auto;
-    /// The fill color of heading in the text. Just the surrounding text color
+    /// The fill color of text in the heading. Just the surrounding text color
     /// if `auto`.
     pub const FILL: Smart<Paint> = Smart::Auto;
 }
@@ -48,12 +48,12 @@ impl Layout for HeadingNode {
     ) -> Vec<Constrained<Rc<Frame>>> {
         let upscale = (1.6 - 0.1 * self.level as f64).max(0.75);
 
-        let mut local = StyleMap::new();
-        local.set(TextNode::STRONG, true);
-        local.set(TextNode::SIZE, Relative::new(upscale).into());
+        let mut passed = StyleMap::new();
+        passed.set(TextNode::STRONG, true);
+        passed.set(TextNode::SIZE, Relative::new(upscale).into());
 
         if let Smart::Custom(family) = styles.get_ref(Self::FAMILY) {
-            local.set(
+            passed.set(
                 TextNode::FAMILY_LIST,
                 std::iter::once(family)
                     .chain(styles.get_ref(TextNode::FAMILY_LIST))
@@ -63,9 +63,9 @@ impl Layout for HeadingNode {
         }
 
         if let Smart::Custom(fill) = styles.get(Self::FILL) {
-            local.set(TextNode::FILL, fill);
+            passed.set(TextNode::FILL, fill);
         }
 
-        self.child.layout(ctx, regions, local.chain(&styles))
+        self.child.layout(ctx, regions, passed.chain(&styles))
     }
 }
diff --git a/src/library/image.rs b/src/library/image.rs
index 2b91b2fc..c5cb9aeb 100644
--- a/src/library/image.rs
+++ b/src/library/image.rs
@@ -3,18 +3,13 @@
 use std::io;
 
 use super::prelude::*;
-use super::LinkNode;
 use crate::diag::Error;
 use crate::image::ImageId;
 
 /// `image`: An image.
 pub fn image(ctx: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
-    let path = args.expect::<Spanned<EcoString>>("path to image file")?;
-    let width = args.named("width")?;
-    let height = args.named("height")?;
-    let fit = args.named("fit")?.unwrap_or_default();
-
     // Load the image.
+    let path = args.expect::<Spanned<EcoString>>("path to image file")?;
     let full = ctx.make_path(&path.v);
     let id = ctx.images.load(&full).map_err(|err| {
         Error::boxed(path.span, match err.kind() {
@@ -23,6 +18,10 @@ pub fn image(ctx: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
         })
     })?;
 
+    let width = args.named("width")?;
+    let height = args.named("height")?;
+    let fit = args.named("fit")?.unwrap_or_default();
+
     Ok(Value::inline(
         ImageNode { id, fit }.pack().sized(Spec::new(width, height)),
     ))
@@ -37,6 +36,12 @@ pub struct ImageNode {
     pub fit: ImageFit,
 }
 
+#[properties]
+impl ImageNode {
+    /// An URL the image should link to.
+    pub const LINK: Option<String> = None;
+}
+
 impl Layout for ImageNode {
     fn layout(
         &self,
@@ -90,7 +95,7 @@ impl Layout for ImageNode {
         }
 
         // Apply link if it exists.
-        if let Some(url) = styles.get_ref(LinkNode::URL) {
+        if let Some(url) = styles.get_ref(Self::LINK) {
             frame.link(url);
         }
 
diff --git a/src/library/link.rs b/src/library/link.rs
index d1d7842d..1050963c 100644
--- a/src/library/link.rs
+++ b/src/library/link.rs
@@ -1,9 +1,10 @@
 //! Hyperlinking.
 
 use super::prelude::*;
+use super::{ImageNode, ShapeNode, TextNode};
 use crate::util::EcoString;
 
-/// `link`: Link text or other elements.
+/// `link`: Link text and other elements to an URL.
 pub fn link(_: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
     let url: String = args.expect::<EcoString>("url")?.into();
     let body = args.find().unwrap_or_else(|| {
@@ -14,17 +15,9 @@ pub fn link(_: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
         Node::Text(text.into())
     });
 
-    Ok(Value::Node(
-        body.styled(StyleMap::with(LinkNode::URL, Some(url))),
-    ))
-}
-
-/// Host for link styles.
-#[derive(Debug, Hash)]
-pub struct LinkNode;
-
-#[properties]
-impl LinkNode {
-    /// An URL to link to.
-    pub const URL: Option<String> = None;
+    let mut passed = StyleMap::new();
+    passed.set(TextNode::LINK, Some(url.clone()));
+    passed.set(ImageNode::LINK, Some(url.clone()));
+    passed.set(ShapeNode::LINK, Some(url));
+    Ok(Value::Node(body.styled(passed)))
 }
diff --git a/src/library/list.rs b/src/library/list.rs
index a9dfbec5..bbdc400a 100644
--- a/src/library/list.rs
+++ b/src/library/list.rs
@@ -50,26 +50,23 @@ impl<L: Labelling> Layout for ListNode<L> {
         let label_indent = styles.get(Self::LABEL_INDENT).resolve(em);
         let body_indent = styles.get(Self::BODY_INDENT).resolve(em);
 
-        let columns = vec![
-            TrackSizing::Linear(label_indent.into()),
-            TrackSizing::Auto,
-            TrackSizing::Linear(body_indent.into()),
-            TrackSizing::Auto,
-        ];
-
-        let children = vec![
-            PackedNode::default(),
-            Node::Text(self.labelling.label()).into_block(),
-            PackedNode::default(),
-            self.child.clone(),
-        ];
-
-        GridNode {
-            tracks: Spec::new(columns, vec![]),
+        let grid = GridNode {
+            tracks: Spec::with_x(vec![
+                TrackSizing::Linear(label_indent.into()),
+                TrackSizing::Auto,
+                TrackSizing::Linear(body_indent.into()),
+                TrackSizing::Auto,
+            ]),
             gutter: Spec::default(),
-            children,
-        }
-        .layout(ctx, regions, styles)
+            children: vec![
+                PackedNode::default(),
+                Node::Text(self.labelling.label()).into_block(),
+                PackedNode::default(),
+                self.child.clone(),
+            ],
+        };
+
+        grid.layout(ctx, regions, styles)
     }
 }
 
diff --git a/src/library/page.rs b/src/library/page.rs
index 69be2bb7..fa9345f5 100644
--- a/src/library/page.rs
+++ b/src/library/page.rs
@@ -166,31 +166,6 @@ pub fn pagebreak(_: &mut EvalContext, _: &mut Args) -> TypResult<Value> {
     Ok(Value::Node(Node::Pagebreak))
 }
 
-/// Defines default margins for a class of related papers.
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
-pub enum PaperClass {
-    Custom,
-    Base,
-    US,
-    Newspaper,
-    Book,
-}
-
-impl PaperClass {
-    /// The default margins for this page class.
-    fn default_margins(self) -> Sides<Linear> {
-        let f = |r| Relative::new(r).into();
-        let s = |l, t, r, b| Sides::new(f(l), f(t), f(r), f(b));
-        match self {
-            Self::Custom => s(0.1190, 0.0842, 0.1190, 0.0842),
-            Self::Base => s(0.1190, 0.0842, 0.1190, 0.0842),
-            Self::US => s(0.1760, 0.1092, 0.1760, 0.0910),
-            Self::Newspaper => s(0.0455, 0.0587, 0.0455, 0.0294),
-            Self::Book => s(0.1200, 0.0852, 0.1500, 0.0965),
-        }
-    }
-}
-
 /// Specification of a paper.
 #[derive(Debug, Copy, Clone)]
 pub struct Paper {
@@ -413,6 +388,31 @@ castable! {
     Value::Str(string) => Paper::from_str(&string).map_err(|e| e.to_string())?,
 }
 
+/// Defines default margins for a class of related papers.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+pub enum PaperClass {
+    Custom,
+    Base,
+    US,
+    Newspaper,
+    Book,
+}
+
+impl PaperClass {
+    /// The default margins for this page class.
+    fn default_margins(self) -> Sides<Linear> {
+        let f = |r| Relative::new(r).into();
+        let s = |l, t, r, b| Sides::new(f(l), f(t), f(r), f(b));
+        match self {
+            Self::Custom => s(0.1190, 0.0842, 0.1190, 0.0842),
+            Self::Base => s(0.1190, 0.0842, 0.1190, 0.0842),
+            Self::US => s(0.1760, 0.1092, 0.1760, 0.0910),
+            Self::Newspaper => s(0.0455, 0.0587, 0.0455, 0.0294),
+            Self::Book => s(0.1200, 0.0852, 0.1500, 0.0965),
+        }
+    }
+}
+
 /// The error when parsing a [`Paper`] from a string fails.
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub struct PaperError;
diff --git a/src/library/placed.rs b/src/library/placed.rs
index 8a4f46af..e7b17325 100644
--- a/src/library/placed.rs
+++ b/src/library/placed.rs
@@ -5,7 +5,7 @@ use super::AlignNode;
 
 /// `place`: Place content at an absolute position.
 pub fn place(_: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
-    let aligns = args.find().unwrap_or(Spec::new(Some(Align::Left), None));
+    let aligns = args.find().unwrap_or(Spec::with_x(Some(Align::Left)));
     let tx = args.named("dx")?.unwrap_or_default();
     let ty = args.named("dy")?.unwrap_or_default();
     let body: PackedNode = args.expect("body")?;
diff --git a/src/library/shape.rs b/src/library/shape.rs
index 76c03edb..c47885d2 100644
--- a/src/library/shape.rs
+++ b/src/library/shape.rs
@@ -3,7 +3,6 @@
 use std::f64::consts::SQRT_2;
 
 use super::prelude::*;
-use super::LinkNode;
 
 /// `rect`: A rectangle with optional content.
 pub fn rect(_: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
@@ -101,6 +100,12 @@ pub struct ShapeNode {
     pub child: Option<PackedNode>,
 }
 
+#[properties]
+impl ShapeNode {
+    /// An URL the shape should link to.
+    pub const LINK: Option<String> = None;
+}
+
 impl Layout for ShapeNode {
     fn layout(
         &self,
@@ -170,7 +175,7 @@ impl Layout for ShapeNode {
         }
 
         // Apply link if it exists.
-        if let Some(url) = styles.get_ref(LinkNode::URL) {
+        if let Some(url) = styles.get_ref(Self::LINK) {
             frame.link(url);
         }
 
diff --git a/src/library/text.rs b/src/library/text.rs
index 5fa19cb9..486cb77f 100644
--- a/src/library/text.rs
+++ b/src/library/text.rs
@@ -9,7 +9,6 @@ use rustybuzz::{Feature, UnicodeBuffer};
 use ttf_parser::Tag;
 
 use super::prelude::*;
-use super::LinkNode;
 use crate::font::{
     Face, FaceId, FontStore, FontStretch, FontStyle, FontVariant, FontWeight,
     VerticalFontMetric,
@@ -59,6 +58,8 @@ impl TextNode {
     /// Decorative lines.
     #[fold(|a, b| a.into_iter().chain(b).collect())]
     pub const LINES: Vec<LineDecoration> = vec![];
+    /// An URL the text should link to.
+    pub const LINK: Option<String> = None;
 
     /// The size of the glyphs.
     #[fold(Linear::compose)]
@@ -889,7 +890,7 @@ impl<'a> ShapedText<'a> {
         }
 
         // Apply link if it exists.
-        if let Some(url) = self.styles.get_ref(LinkNode::URL) {
+        if let Some(url) = self.styles.get_ref(TextNode::LINK) {
             frame.link(url);
         }