Introspection

12 files changed, 79 insertions, 36 deletions

diff --git a/library/src/basics/list.rs b/library/src/basics/list.rs
index e35fe9fa..f5a58977 100644
--- a/library/src/basics/list.rs
+++ b/library/src/basics/list.rs
@@ -216,7 +216,7 @@ pub const ENUM: ListKind = 1;
 pub const DESC: ListKind = 2;
 
 /// How to label a list or enumeration.
-#[derive(Debug, Clone, PartialEq, Hash)]
+#[derive(Debug, Clone, Hash)]
 pub enum Label {
     /// The default labelling.
     Default,
diff --git a/library/src/layout/mod.rs b/library/src/layout/mod.rs
index e3691732..047d78f9 100644
--- a/library/src/layout/mod.rs
+++ b/library/src/layout/mod.rs
@@ -59,9 +59,11 @@ impl LayoutRoot for Content {
         fn cached(
             node: &Content,
             world: comemo::Tracked<dyn World>,
+            provider: TrackedMut<StabilityProvider>,
+            introspector: Tracked<Introspector>,
             styles: StyleChain,
         ) -> SourceResult<Document> {
-            let mut vt = Vt { world };
+            let mut vt = Vt { world, provider, introspector };
             let scratch = Scratch::default();
             let (realized, styles) = realize_root(&mut vt, &scratch, node, styles)?;
             realized
@@ -70,7 +72,13 @@ impl LayoutRoot for Content {
                 .layout_root(&mut vt, styles)
         }
 
-        cached(self, vt.world, styles)
+        cached(
+            self,
+            vt.world,
+            TrackedMut::reborrow_mut(&mut vt.provider),
+            vt.introspector,
+            styles,
+        )
     }
 }
 
@@ -97,10 +105,12 @@ impl Layout for Content {
         fn cached(
             node: &Content,
             world: comemo::Tracked<dyn World>,
+            provider: TrackedMut<StabilityProvider>,
+            introspector: Tracked<Introspector>,
             styles: StyleChain,
             regions: &Regions,
         ) -> SourceResult<Fragment> {
-            let mut vt = Vt { world };
+            let mut vt = Vt { world, provider, introspector };
             let scratch = Scratch::default();
             let (realized, styles) = realize_block(&mut vt, &scratch, node, styles)?;
             let barrier = Style::Barrier(realized.id());
@@ -111,7 +121,14 @@ impl Layout for Content {
                 .layout(&mut vt, styles, regions)
         }
 
-        cached(self, vt.world, styles, regions)
+        cached(
+            self,
+            vt.world,
+            TrackedMut::reborrow_mut(&mut vt.provider),
+            vt.introspector,
+            styles,
+            regions,
+        )
     }
 }
 
@@ -290,6 +307,15 @@ impl<'a, 'v, 't> Builder<'a, 'v, 't> {
         content: &'a Content,
         styles: StyleChain<'a>,
     ) -> SourceResult<()> {
+        // Prepare only if this is the first application for this node.
+        if let Some(node) = content.with::<dyn Prepare>() {
+            if !content.is_prepared() {
+                let prepared = node.prepare(self.vt, content.clone().prepared(), styles);
+                let stored = self.scratch.content.alloc(prepared);
+                return self.accept(stored, styles);
+            }
+        }
+
         if let Some(styled) = content.to::<StyledNode>() {
             return self.styled(styled, styles);
         }
diff --git a/library/src/layout/page.rs b/library/src/layout/page.rs
index 08411ad1..dee77abd 100644
--- a/library/src/layout/page.rs
+++ b/library/src/layout/page.rs
@@ -5,7 +5,7 @@ use crate::prelude::*;
 use crate::text::TextNode;
 
 /// Layouts its child onto one or multiple pages.
-#[derive(PartialEq, Clone, Hash)]
+#[derive(Clone, Hash)]
 pub struct PageNode(pub Content);
 
 #[node]
@@ -157,7 +157,7 @@ impl PagebreakNode {
 }
 
 /// A header, footer, foreground or background definition.
-#[derive(Debug, Clone, PartialEq, Hash)]
+#[derive(Debug, Clone, Hash)]
 pub enum Marginal {
     /// Nothing,
     None,
diff --git a/library/src/layout/par.rs b/library/src/layout/par.rs
index e96845dd..78e9b2a3 100644
--- a/library/src/layout/par.rs
+++ b/library/src/layout/par.rs
@@ -57,13 +57,15 @@ impl ParNode {
         fn cached(
             par: &ParNode,
             world: Tracked<dyn World>,
+            provider: TrackedMut<StabilityProvider>,
+            introspector: Tracked<Introspector>,
             styles: StyleChain,
             consecutive: bool,
             width: Abs,
             base: Size,
             expand: bool,
         ) -> SourceResult<Fragment> {
-            let mut vt = Vt { world };
+            let mut vt = Vt { world, provider, introspector };
 
             // Collect all text into one string for BiDi analysis.
             let (text, segments) = collect(par, &styles, consecutive);
@@ -80,7 +82,17 @@ impl ParNode {
             finalize(&mut vt, &p, &lines, width, base, expand)
         }
 
-        cached(self, vt.world, styles, consecutive, width, base, expand)
+        cached(
+            self,
+            vt.world,
+            TrackedMut::reborrow_mut(&mut vt.provider),
+            vt.introspector,
+            styles,
+            consecutive,
+            width,
+            base,
+            expand,
+        )
     }
 }
 
diff --git a/library/src/meta/document.rs b/library/src/meta/document.rs
index 77181671..fbb62b6b 100644
--- a/library/src/meta/document.rs
+++ b/library/src/meta/document.rs
@@ -27,11 +27,9 @@ impl LayoutRoot for DocumentNode {
         }
 
         Ok(Document {
-            metadata: Metadata {
-                title: styles.get(Self::TITLE).clone(),
-                author: styles.get(Self::AUTHOR).clone(),
-            },
             pages,
+            title: styles.get(Self::TITLE).clone(),
+            author: styles.get(Self::AUTHOR).clone(),
         })
     }
 }
diff --git a/library/src/meta/link.rs b/library/src/meta/link.rs
index e7d217e7..52163371 100644
--- a/library/src/meta/link.rs
+++ b/library/src/meta/link.rs
@@ -25,10 +25,6 @@ impl LinkNode {
 
 #[node(Show, Finalize)]
 impl LinkNode {
-    /// A destination the text should be linked to.
-    #[property(skip, referenced)]
-    pub(crate) const DEST: Option<Destination> = None;
-
     fn construct(_: &Vm, args: &mut Args) -> SourceResult<Content> {
         let dest = args.expect::<Destination>("destination")?;
         Ok(match dest {
@@ -61,6 +57,6 @@ impl Show for LinkNode {
 
 impl Finalize for LinkNode {
     fn finalize(&self, realized: Content) -> Content {
-        realized.styled(Self::DEST, Some(self.dest.clone()))
+        realized.styled(Meta::DATA, vec![Meta::Link(self.dest.clone())])
     }
 }
diff --git a/library/src/prelude.rs b/library/src/prelude.rs
index e7d824cc..26a3c6c3 100644
--- a/library/src/prelude.rs
+++ b/library/src/prelude.rs
@@ -16,8 +16,9 @@ pub use typst::geom::*;
 #[doc(no_inline)]
 pub use typst::model::{
     array, capability, castable, dict, dynamic, format_str, node, Args, Array, Cast,
-    Content, Dict, Finalize, Fold, Func, Label, Node, NodeId, Resolve, Selector, Show,
-    Smart, Str, StyleChain, StyleMap, StyleVec, Unlabellable, Value, Vm, Vt,
+    Content, Dict, Finalize, Fold, Func, Introspector, Label, Node, NodeId, Prepare,
+    Resolve, Selector, Show, Smart, StabilityProvider, Str, StyleChain, StyleMap,
+    StyleVec, Unlabellable, Value, Vm, Vt,
 };
 #[doc(no_inline)]
 pub use typst::syntax::{Span, Spanned};
diff --git a/library/src/shared/ext.rs b/library/src/shared/ext.rs
index 2d2dc751..4fd1f161 100644
--- a/library/src/shared/ext.rs
+++ b/library/src/shared/ext.rs
@@ -13,6 +13,9 @@ pub trait ContentExt {
     /// Underline this content.
     fn underlined(self) -> Self;
 
+    /// Link the content to a destination.
+    fn linked(self, dest: Destination) -> Self;
+
     /// Force a size for this content.
     fn boxed(self, sizing: Axes<Option<Rel<Length>>>) -> Self;
 
@@ -45,6 +48,10 @@ impl ContentExt for Content {
         crate::text::DecoNode::<{ crate::text::UNDERLINE }>(self).pack()
     }
 
+    fn linked(self, dest: Destination) -> Self {
+        self.styled(Meta::DATA, vec![Meta::Link(dest.clone())])
+    }
+
     fn boxed(self, sizing: Axes<Option<Rel<Length>>>) -> Self {
         crate::layout::BoxNode { sizing, child: self }.pack()
     }
diff --git a/library/src/text/raw.rs b/library/src/text/raw.rs
index c0bf105f..9c04fedf 100644
--- a/library/src/text/raw.rs
+++ b/library/src/text/raw.rs
@@ -42,6 +42,19 @@ impl RawNode {
     }
 }
 
+impl Prepare for RawNode {
+    fn prepare(&self, _: &mut Vt, mut this: Content, styles: StyleChain) -> Content {
+        this.push_field(
+            "lang",
+            match styles.get(Self::LANG) {
+                Some(lang) => Value::Str(lang.clone().into()),
+                None => Value::None,
+            },
+        );
+        this
+    }
+}
+
 impl Show for RawNode {
     fn show(&self, _: &mut Vt, _: &Content, styles: StyleChain) -> Content {
         let lang = styles.get(Self::LANG).as_ref().map(|s| s.to_lowercase());
diff --git a/library/src/text/shaping.rs b/library/src/text/shaping.rs
index 6dbbb535..6d4e41dc 100644
--- a/library/src/text/shaping.rs
+++ b/library/src/text/shaping.rs
@@ -6,7 +6,6 @@ use typst::font::{Font, FontVariant};
 use typst::util::SliceExt;
 
 use super::*;
-use crate::meta::LinkNode;
 use crate::prelude::*;
 
 /// The result of shaping text.
@@ -93,7 +92,6 @@ impl<'a> ShapedText<'a> {
         let lang = self.styles.get(TextNode::LANG);
         let decos = self.styles.get(TextNode::DECO);
         let fill = self.styles.get(TextNode::FILL);
-        let link = self.styles.get(LinkNode::DEST);
 
         for ((font, y_offset), group) in
             self.glyphs.as_ref().group_by_key(|g| (g.font.clone(), g.y_offset))
@@ -128,10 +126,8 @@ impl<'a> ShapedText<'a> {
             offset += width;
         }
 
-        // Apply link if it exists.
-        if let Some(dest) = link {
-            frame.link(dest.clone());
-        }
+        // Apply metadata.
+        frame.meta(self.styles);
 
         frame
     }
diff --git a/library/src/visualize/image.rs b/library/src/visualize/image.rs
index 077fe76d..48764c37 100644
--- a/library/src/visualize/image.rs
+++ b/library/src/visualize/image.rs
@@ -2,7 +2,6 @@ use std::ffi::OsStr;
 
 use typst::image::{Image, ImageFormat, RasterFormat, VectorFormat};
 
-use crate::meta::LinkNode;
 use crate::prelude::*;
 
 /// Show a raster or vector graphic.
@@ -89,10 +88,8 @@ impl Layout for ImageNode {
             frame.clip();
         }
 
-        // Apply link if it exists.
-        if let Some(url) = styles.get(LinkNode::DEST) {
-            frame.link(url.clone());
-        }
+        // Apply metadata.
+        frame.meta(styles);
 
         Ok(Fragment::frame(frame))
     }
diff --git a/library/src/visualize/shape.rs b/library/src/visualize/shape.rs
index f2d15cab..acb5a9e9 100644
--- a/library/src/visualize/shape.rs
+++ b/library/src/visualize/shape.rs
@@ -1,6 +1,5 @@
 use std::f64::consts::SQRT_2;
 
-use crate::meta::LinkNode;
 use crate::prelude::*;
 
 /// A sizable and fillable shape with optional content.
@@ -160,10 +159,8 @@ impl<const S: ShapeKind> Layout for ShapeNode<S> {
             }
         }
 
-        // Apply link if it exists.
-        if let Some(url) = styles.get(LinkNode::DEST) {
-            frame.link(url.clone());
-        }
+        // Apply metadata.
+        frame.meta(styles);
 
         Ok(Fragment::frame(frame))
     }