Refactor syntax module

4 files changed, 745 insertions, 808 deletions

diff --git a/src/syntax/ast.rs b/src/syntax/ast.rs
index 6a016e79..aa590da2 100644
--- a/src/syntax/ast.rs
+++ b/src/syntax/ast.rs
@@ -1,6 +1,6 @@
 //! A typed layer over the untyped syntax tree.
 //!
-//! The AST is rooted in the [`Markup`] node.
+//! The AST is rooted in the [`MarkupNode`].
 
 use std::num::NonZeroUsize;
 use std::ops::Deref;
@@ -54,19 +54,19 @@ macro_rules! node {
 
 node! {
     /// The syntactical root capable of representing a full parsed document.
-    Markup: NodeKind::Markup { .. }
+    MarkupNode: NodeKind::Markup { .. }
 }
 
-impl Markup {
-    /// The markup nodes.
-    pub fn nodes(&self) -> impl Iterator<Item = MarkupNode> + '_ {
+impl MarkupNode {
+    /// The children.
+    pub fn items(&self) -> impl Iterator<Item = MarkupItem> + '_ {
         self.0.children().filter_map(SyntaxNode::cast)
     }
 }
 
 /// A single piece of markup.
 #[derive(Debug, Clone, PartialEq)]
-pub enum MarkupNode {
+pub enum MarkupItem {
     /// Whitespace containing less than two newlines.
     Space,
     /// A forced line break.
@@ -81,34 +81,34 @@ pub enum MarkupNode {
     Strong(StrongNode),
     /// Emphasized content: `_Emphasized_`.
     Emph(EmphNode),
-    /// A hyperlink.
+    /// A hyperlink: `https://typst.org`.
     Link(EcoString),
     /// A raw block with optional syntax highlighting: `` `...` ``.
     Raw(RawNode),
-    /// A math formula: `$a^2 = b^2 + c^2$`.
-    Math(Math),
+    /// A math formula: `$x$`, `$ x^2 $`.
+    Math(MathNode),
     /// A section heading: `= Introduction`.
     Heading(HeadingNode),
     /// An item in an unordered list: `- ...`.
-    List(ListNode),
+    List(ListItem),
     /// An item in an enumeration (ordered list): `+ ...` or `1. ...`.
-    Enum(EnumNode),
-    /// An item in a description list: `/ Term: Details.
-    Desc(DescNode),
-    /// A label.
+    Enum(EnumItem),
+    /// An item in a description list: `/ Term: Details`.
+    Desc(DescItem),
+    /// A label: `<label>`.
     Label(EcoString),
-    /// A reference.
+    /// A reference: `@label`.
     Ref(EcoString),
     /// An expression.
     Expr(Expr),
 }
 
-impl TypedNode for MarkupNode {
+impl TypedNode for MarkupItem {
     fn from_untyped(node: &SyntaxNode) -> Option<Self> {
         match node.kind() {
             NodeKind::Space { newlines: (2 ..) } => Some(Self::Parbreak),
             NodeKind::Space { .. } => Some(Self::Space),
-            NodeKind::Linebreak => Some(Self::Linebreak),
+            NodeKind::Backslash => Some(Self::Linebreak),
             NodeKind::Text(s) => Some(Self::Text(s.clone())),
             NodeKind::Escape(c) => Some(Self::Text((*c).into())),
             NodeKind::Tilde => Some(Self::Text('\u{00A0}'.into())),
@@ -123,9 +123,9 @@ impl TypedNode for MarkupNode {
             NodeKind::Raw(raw) => Some(Self::Raw(raw.as_ref().clone())),
             NodeKind::Math => node.cast().map(Self::Math),
             NodeKind::Heading => node.cast().map(Self::Heading),
-            NodeKind::List => node.cast().map(Self::List),
-            NodeKind::Enum => node.cast().map(Self::Enum),
-            NodeKind::Desc => node.cast().map(Self::Desc),
+            NodeKind::ListItem => node.cast().map(Self::List),
+            NodeKind::EnumItem => node.cast().map(Self::Enum),
+            NodeKind::DescItem => node.cast().map(Self::Desc),
             NodeKind::Label(v) => Some(Self::Label(v.clone())),
             NodeKind::Ref(v) => Some(Self::Ref(v.clone())),
             _ => node.cast().map(Self::Expr),
@@ -144,7 +144,7 @@ node! {
 
 impl StrongNode {
     /// The contents of the strong node.
-    pub fn body(&self) -> Markup {
+    pub fn body(&self) -> MarkupNode {
         self.0.cast_first_child().expect("strong node is missing markup body")
     }
 }
@@ -156,7 +156,7 @@ node! {
 
 impl EmphNode {
     /// The contents of the emphasis node.
-    pub fn body(&self) -> Markup {
+    pub fn body(&self) -> MarkupNode {
         self.0
             .cast_first_child()
             .expect("emphasis node is missing markup body")
@@ -178,19 +178,19 @@ pub struct RawNode {
 
 node! {
     /// A math formula: `$x$`, `$ x^2 $`.
-    Math: NodeKind::Math { .. }
+    MathNode: NodeKind::Math { .. }
 }
 
-impl Math {
-    /// The math nodes.
-    pub fn nodes(&self) -> impl Iterator<Item = MathNode> + '_ {
+impl MathNode {
+    /// The children.
+    pub fn items(&self) -> impl Iterator<Item = MathItem> + '_ {
         self.0.children().filter_map(SyntaxNode::cast)
     }
 }
 
 /// A single piece of a math formula.
 #[derive(Debug, Clone, PartialEq, Hash)]
-pub enum MathNode {
+pub enum MathItem {
     /// Whitespace.
     Space,
     /// A forced line break.
@@ -201,15 +201,15 @@ pub enum MathNode {
     Script(ScriptNode),
     /// A fraction: `x/2`.
     Frac(FracNode),
-    /// A math alignment indicator: `&`, `&&`.
+    /// An alignment indicator: `&`, `&&`.
     Align(AlignNode),
     /// Grouped mathematical material.
-    Group(Math),
+    Group(MathNode),
     /// An expression.
     Expr(Expr),
 }
 
-impl TypedNode for MathNode {
+impl TypedNode for MathItem {
     fn from_untyped(node: &SyntaxNode) -> Option<Self> {
         match node.kind() {
             NodeKind::Space { .. } => Some(Self::Space),
@@ -219,7 +219,7 @@ impl TypedNode for MathNode {
             NodeKind::RightBracket => Some(Self::Atom(']'.into())),
             NodeKind::LeftParen => Some(Self::Atom('('.into())),
             NodeKind::RightParen => Some(Self::Atom(')'.into())),
-            NodeKind::Linebreak => Some(Self::Linebreak),
+            NodeKind::Backslash => Some(Self::Linebreak),
             NodeKind::Escape(c) => Some(Self::Atom((*c).into())),
             NodeKind::Atom(atom) => Some(Self::Atom(atom.clone())),
             NodeKind::Script => node.cast().map(Self::Script),
@@ -242,12 +242,12 @@ node! {
 
 impl ScriptNode {
     /// The base of the script.
-    pub fn base(&self) -> MathNode {
+    pub fn base(&self) -> MathItem {
         self.0.cast_first_child().expect("subscript is missing base")
     }
 
     /// The subscript.
-    pub fn sub(&self) -> Option<MathNode> {
+    pub fn sub(&self) -> Option<MathItem> {
         self.0
             .children()
             .skip_while(|node| !matches!(node.kind(), NodeKind::Underscore))
@@ -256,7 +256,7 @@ impl ScriptNode {
     }
 
     /// The superscript.
-    pub fn sup(&self) -> Option<MathNode> {
+    pub fn sup(&self) -> Option<MathItem> {
         self.0
             .children()
             .skip_while(|node| !matches!(node.kind(), NodeKind::Hat))
@@ -272,12 +272,12 @@ node! {
 
 impl FracNode {
     /// The numerator.
-    pub fn num(&self) -> MathNode {
+    pub fn num(&self) -> MathItem {
         self.0.cast_first_child().expect("fraction is missing numerator")
     }
 
     /// The denominator.
-    pub fn denom(&self) -> MathNode {
+    pub fn denom(&self) -> MathItem {
         self.0.cast_last_child().expect("fraction is missing denominator")
     }
 }
@@ -301,7 +301,7 @@ node! {
 
 impl HeadingNode {
     /// The contents of the heading.
-    pub fn body(&self) -> Markup {
+    pub fn body(&self) -> MarkupNode {
         self.0.cast_first_child().expect("heading is missing markup body")
     }
 
@@ -318,27 +318,22 @@ impl HeadingNode {
 
 node! {
     /// An item in an unordered list: `- ...`.
-    ListNode: List
+    ListItem: ListItem
 }
 
-impl ListNode {
+impl ListItem {
     /// The contents of the list item.
-    pub fn body(&self) -> Markup {
+    pub fn body(&self) -> MarkupNode {
         self.0.cast_first_child().expect("list item is missing body")
     }
 }
 
 node! {
     /// An item in an enumeration (ordered list): `1. ...`.
-    EnumNode: Enum
+    EnumItem: EnumItem
 }
 
-impl EnumNode {
-    /// The contents of the list item.
-    pub fn body(&self) -> Markup {
-        self.0.cast_first_child().expect("enum item is missing body")
-    }
-
+impl EnumItem {
     /// The number, if any.
     pub fn number(&self) -> Option<usize> {
         self.0.children().find_map(|node| match node.kind() {
@@ -346,23 +341,28 @@ impl EnumNode {
             _ => None,
         })
     }
+
+    /// The contents of the list item.
+    pub fn body(&self) -> MarkupNode {
+        self.0.cast_first_child().expect("enum item is missing body")
+    }
 }
 
 node! {
-    /// An item in a description list: `/ Term: Details.
-    DescNode: Desc
+    /// An item in a description list: `/ Term: Details`.
+    DescItem: DescItem
 }
 
-impl DescNode {
-    /// The term described by the list item.
-    pub fn term(&self) -> Markup {
+impl DescItem {
+    /// The term described by the item.
+    pub fn term(&self) -> MarkupNode {
         self.0
             .cast_first_child()
             .expect("description list item is missing term")
     }
 
     /// The description of the term.
-    pub fn body(&self) -> Markup {
+    pub fn body(&self) -> MarkupNode {
         self.0
             .cast_last_child()
             .expect("description list item is missing body")
@@ -586,7 +586,7 @@ node! {
 
 impl ContentBlock {
     /// The contained markup.
-    pub fn body(&self) -> Markup {
+    pub fn body(&self) -> MarkupNode {
         self.0.cast_first_child().expect("content is missing body")
     }
 }
diff --git a/src/syntax/highlight.rs b/src/syntax/highlight.rs
index e3640562..60d349d1 100644
--- a/src/syntax/highlight.rs
+++ b/src/syntax/highlight.rs
@@ -1,3 +1,5 @@
+//! Syntax highlighting for Typst source code.
+
 use std::fmt::Write;
 use std::ops::Range;
 
@@ -5,85 +7,9 @@ use syntect::highlighting::{Color, FontStyle, Highlighter, Style, Theme};
 use syntect::parsing::Scope;
 
 use super::{NodeKind, SyntaxNode};
-use crate::parse::TokenMode;
-
-/// Provide highlighting categories for the descendants of a node that fall into
-/// a range.
-pub fn highlight_node<F>(root: &SyntaxNode, range: Range<usize>, mut f: F)
-where
-    F: FnMut(Range<usize>, Category),
-{
-    highlight_node_impl(0, root, range, &mut f)
-}
-
-/// Provide highlighting categories for the descendants of a node that fall into
-/// a range.
-pub fn highlight_node_impl<F>(
-    mut offset: usize,
-    node: &SyntaxNode,
-    range: Range<usize>,
-    f: &mut F,
-) where
-    F: FnMut(Range<usize>, Category),
-{
-    for (i, child) in node.children().enumerate() {
-        let span = offset .. offset + child.len();
-        if range.start <= span.end && range.end >= span.start {
-            if let Some(category) = Category::determine(child, node, i) {
-                f(span, category);
-            }
-            highlight_node_impl(offset, child, range.clone(), f);
-        }
-        offset += child.len();
-    }
-}
-
-/// Highlight source text in a theme by calling `f` with each consecutive piece
-/// and its style.
-pub fn highlight_themed<F>(text: &str, mode: TokenMode, theme: &Theme, mut f: F)
-where
-    F: FnMut(&str, Style),
-{
-    let root = match mode {
-        TokenMode::Markup => crate::parse::parse(text),
-        TokenMode::Math => crate::parse::parse_math(text),
-        TokenMode::Code => crate::parse::parse_code(text),
-    };
-
-    let highlighter = Highlighter::new(&theme);
-    highlight_themed_impl(text, 0, &root, vec![], &highlighter, &mut f);
-}
-
-/// Recursive implementation for highlighting with a syntect theme.
-fn highlight_themed_impl<F>(
-    text: &str,
-    mut offset: usize,
-    node: &SyntaxNode,
-    scopes: Vec<Scope>,
-    highlighter: &Highlighter,
-    f: &mut F,
-) where
-    F: FnMut(&str, Style),
-{
-    if node.children().len() == 0 {
-        let piece = &text[offset .. offset + node.len()];
-        let style = highlighter.style_for_stack(&scopes);
-        f(piece, style);
-        return;
-    }
-
-    for (i, child) in node.children().enumerate() {
-        let mut scopes = scopes.clone();
-        if let Some(category) = Category::determine(child, node, i) {
-            scopes.push(Scope::new(category.tm_scope()).unwrap())
-        }
-        highlight_themed_impl(text, offset, child, scopes, highlighter, f);
-        offset += child.len();
-    }
-}
 
 /// Highlight source text into a standalone HTML document.
-pub fn highlight_html(text: &str, mode: TokenMode, theme: &Theme) -> String {
+pub fn highlight_html(text: &str, theme: &Theme) -> String {
     let mut buf = String::new();
     buf.push_str("<!DOCTYPE html>\n");
     buf.push_str("<html>\n");
@@ -91,18 +17,19 @@ pub fn highlight_html(text: &str, mode: TokenMode, theme: &Theme) -> String {
     buf.push_str("  <meta charset=\"utf-8\">\n");
     buf.push_str("</head>\n");
     buf.push_str("<body>\n");
-    buf.push_str(&highlight_pre(text, mode, theme));
+    buf.push_str(&highlight_pre(text, theme));
     buf.push_str("\n</body>\n");
     buf.push_str("</html>\n");
     buf
 }
 
 /// Highlight source text into an HTML pre element.
-pub fn highlight_pre(text: &str, mode: TokenMode, theme: &Theme) -> String {
+pub fn highlight_pre(text: &str, theme: &Theme) -> String {
     let mut buf = String::new();
     buf.push_str("<pre>\n");
 
-    highlight_themed(text, mode, theme, |piece, style| {
+    let root = crate::parse::parse(text);
+    highlight_themed(&root, theme, |range, style| {
         let styled = style != Style::default();
         if styled {
             buf.push_str("<span style=\"");
@@ -127,7 +54,7 @@ pub fn highlight_pre(text: &str, mode: TokenMode, theme: &Theme) -> String {
             buf.push_str("\">");
         }
 
-        buf.push_str(piece);
+        buf.push_str(&text[range]);
 
         if styled {
             buf.push_str("</span>");
@@ -138,19 +65,82 @@ pub fn highlight_pre(text: &str, mode: TokenMode, theme: &Theme) -> String {
     buf
 }
 
+/// Highlight a syntax node in a theme by calling `f` with ranges and their
+/// styles.
+pub fn highlight_themed<F>(root: &SyntaxNode, theme: &Theme, mut f: F)
+where
+    F: FnMut(Range<usize>, Style),
+{
+    fn process<F>(
+        mut offset: usize,
+        node: &SyntaxNode,
+        scopes: Vec<Scope>,
+        highlighter: &Highlighter,
+        f: &mut F,
+    ) where
+        F: FnMut(Range<usize>, Style),
+    {
+        if node.children().len() == 0 {
+            let range = offset .. offset + node.len();
+            let style = highlighter.style_for_stack(&scopes);
+            f(range, style);
+            return;
+        }
+
+        for (i, child) in node.children().enumerate() {
+            let mut scopes = scopes.clone();
+            if let Some(category) = Category::determine(child, node, i) {
+                scopes.push(Scope::new(category.tm_scope()).unwrap())
+            }
+            process(offset, child, scopes, highlighter, f);
+            offset += child.len();
+        }
+    }
+
+    let highlighter = Highlighter::new(&theme);
+    process(0, root, vec![], &highlighter, &mut f);
+}
+
+/// Highlight a syntax node by calling `f` with ranges overlapping `within` and
+/// their categories.
+pub fn highlight_categories<F>(root: &SyntaxNode, within: Range<usize>, mut f: F)
+where
+    F: FnMut(Range<usize>, Category),
+{
+    fn process<F>(mut offset: usize, node: &SyntaxNode, range: Range<usize>, f: &mut F)
+    where
+        F: FnMut(Range<usize>, Category),
+    {
+        for (i, child) in node.children().enumerate() {
+            let span = offset .. offset + child.len();
+            if range.start <= span.end && range.end >= span.start {
+                if let Some(category) = Category::determine(child, node, i) {
+                    f(span, category);
+                }
+                process(offset, child, range.clone(), f);
+            }
+            offset += child.len();
+        }
+    }
+
+    process(0, root, within, &mut f)
+}
+
 /// The syntax highlighting category of a node.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub enum Category {
     /// A line or block comment.
     Comment,
-    /// Any kind of bracket, parenthesis or brace.
+    /// A square bracket, parenthesis or brace.
     Bracket,
     /// Punctuation in code.
     Punctuation,
-    /// An easily typable shortcut to a unicode codepoint.
-    Shortcut,
     /// An escape sequence.
     Escape,
+    /// An easily typable shortcut to a unicode codepoint.
+    Shortcut,
+    /// A smart quote.
+    Quote,
     /// Strong text.
     Strong,
     /// Emphasized text.
@@ -159,38 +149,40 @@ pub enum Category {
     Link,
     /// Raw text or code.
     Raw,
-    /// A math formula.
+    /// A full math formula.
     Math,
+    /// The delimiters of a math formula.
+    MathDelimiter,
+    /// A symbol with special meaning in a math formula.
+    MathSymbol,
     /// A section heading.
     Heading,
+    /// A full item of a list, enumeration or description list.
+    ListItem,
     /// A marker of a list, enumeration, or description list.
     ListMarker,
     /// A term in a description list.
-    Term,
+    ListTerm,
     /// A label.
     Label,
     /// A reference.
     Ref,
     /// A keyword.
     Keyword,
+    /// A literal defined by a keyword like `none`, `auto` or a boolean.
+    KeywordLiteral,
     /// An operator symbol.
     Operator,
-    /// The none literal.
-    None,
-    /// The auto literal.
-    Auto,
-    /// A boolean literal.
-    Bool,
     /// A numeric literal.
     Number,
     /// A string literal.
     String,
-    /// A function.
+    /// A function or method name.
     Function,
-    /// An interpolated variable in markup.
+    /// An interpolated variable in markup or math.
     Interpolated,
-    /// An invalid node.
-    Invalid,
+    /// A syntax error.
+    Error,
 }
 
 impl Category {
@@ -214,40 +206,38 @@ impl Category {
             NodeKind::RightParen => Some(Category::Bracket),
             NodeKind::Comma => Some(Category::Punctuation),
             NodeKind::Semicolon => Some(Category::Punctuation),
-            NodeKind::Colon => match parent.kind() {
-                NodeKind::Desc => Some(Category::Term),
-                _ => Some(Category::Punctuation),
-            },
+            NodeKind::Colon => Some(Category::Punctuation),
             NodeKind::Star => match parent.kind() {
                 NodeKind::Strong => None,
                 _ => Some(Category::Operator),
             },
             NodeKind::Underscore => match parent.kind() {
-                NodeKind::Script => Some(Category::Shortcut),
+                NodeKind::Script => Some(Category::MathSymbol),
                 _ => None,
             },
-            NodeKind::Dollar => Some(Category::Math),
+            NodeKind::Dollar => Some(Category::MathDelimiter),
+            NodeKind::Backslash => Some(Category::Shortcut),
             NodeKind::Tilde => Some(Category::Shortcut),
             NodeKind::HyphQuest => Some(Category::Shortcut),
             NodeKind::Hyph2 => Some(Category::Shortcut),
             NodeKind::Hyph3 => Some(Category::Shortcut),
             NodeKind::Dot3 => Some(Category::Shortcut),
-            NodeKind::Quote { .. } => None,
-            NodeKind::Plus => match parent.kind() {
-                NodeKind::Enum => Some(Category::ListMarker),
-                _ => Some(Category::Operator),
-            },
-            NodeKind::Minus => match parent.kind() {
-                NodeKind::List => Some(Category::ListMarker),
-                _ => Some(Category::Operator),
-            },
-            NodeKind::Slash => match parent.kind() {
-                NodeKind::Desc => Some(Category::ListMarker),
-                NodeKind::Frac => Some(Category::Shortcut),
-                _ => Some(Category::Operator),
-            },
-            NodeKind::Hat => Some(Category::Shortcut),
-            NodeKind::Amp => Some(Category::Shortcut),
+            NodeKind::Quote { .. } => Some(Category::Quote),
+            NodeKind::Plus => Some(match parent.kind() {
+                NodeKind::EnumItem => Category::ListMarker,
+                _ => Category::Operator,
+            }),
+            NodeKind::Minus => Some(match parent.kind() {
+                NodeKind::ListItem => Category::ListMarker,
+                _ => Category::Operator,
+            }),
+            NodeKind::Slash => Some(match parent.kind() {
+                NodeKind::DescItem => Category::ListMarker,
+                NodeKind::Frac => Category::MathSymbol,
+                _ => Category::Operator,
+            }),
+            NodeKind::Hat => Some(Category::MathSymbol),
+            NodeKind::Amp => Some(Category::MathSymbol),
             NodeKind::Dot => Some(Category::Punctuation),
             NodeKind::Eq => match parent.kind() {
                 NodeKind::Heading => None,
@@ -269,8 +259,8 @@ impl Category {
             NodeKind::Not => Some(Category::Keyword),
             NodeKind::And => Some(Category::Keyword),
             NodeKind::Or => Some(Category::Keyword),
-            NodeKind::None => Some(Category::None),
-            NodeKind::Auto => Some(Category::Auto),
+            NodeKind::None => Some(Category::KeywordLiteral),
+            NodeKind::Auto => Some(Category::KeywordLiteral),
             NodeKind::Let => Some(Category::Keyword),
             NodeKind::Set => Some(Category::Keyword),
             NodeKind::Show => Some(Category::Keyword),
@@ -289,37 +279,35 @@ impl Category {
             NodeKind::As => Some(Category::Keyword),
 
             NodeKind::Markup { .. } => match parent.kind() {
-                NodeKind::Desc
+                NodeKind::DescItem
                     if parent
                         .children()
                         .take_while(|child| child.kind() != &NodeKind::Colon)
                         .find(|c| matches!(c.kind(), NodeKind::Markup { .. }))
                         .map_or(false, |ident| std::ptr::eq(ident, child)) =>
                 {
-                    Some(Category::Term)
+                    Some(Category::ListTerm)
                 }
                 _ => None,
             },
-            NodeKind::Linebreak { .. } => Some(Category::Shortcut),
             NodeKind::Text(_) => None,
             NodeKind::Escape(_) => Some(Category::Escape),
             NodeKind::Strong => Some(Category::Strong),
             NodeKind::Emph => Some(Category::Emph),
             NodeKind::Link(_) => Some(Category::Link),
             NodeKind::Raw(_) => Some(Category::Raw),
-            NodeKind::Math => None,
-            NodeKind::Heading => Some(Category::Heading),
-            NodeKind::List => None,
-            NodeKind::Enum => None,
-            NodeKind::EnumNumbering(_) => Some(Category::ListMarker),
-            NodeKind::Desc => None,
-            NodeKind::Label(_) => Some(Category::Label),
-            NodeKind::Ref(_) => Some(Category::Ref),
-
+            NodeKind::Math => Some(Category::Math),
             NodeKind::Atom(_) => None,
             NodeKind::Script => None,
             NodeKind::Frac => None,
             NodeKind::Align => None,
+            NodeKind::Heading => Some(Category::Heading),
+            NodeKind::ListItem => Some(Category::ListItem),
+            NodeKind::EnumItem => Some(Category::ListItem),
+            NodeKind::EnumNumbering(_) => Some(Category::ListMarker),
+            NodeKind::DescItem => Some(Category::ListItem),
+            NodeKind::Label(_) => Some(Category::Label),
+            NodeKind::Ref(_) => Some(Category::Ref),
 
             NodeKind::Ident(_) => match parent.kind() {
                 NodeKind::Markup { .. } => Some(Category::Interpolated),
@@ -341,7 +329,7 @@ impl Category {
                 }
                 _ => None,
             },
-            NodeKind::Bool(_) => Some(Category::Bool),
+            NodeKind::Bool(_) => Some(Category::KeywordLiteral),
             NodeKind::Int(_) => Some(Category::Number),
             NodeKind::Float(_) => Some(Category::Number),
             NodeKind::Numeric(_, _) => Some(Category::Number),
@@ -377,39 +365,40 @@ impl Category {
             NodeKind::ContinueExpr => None,
             NodeKind::ReturnExpr => None,
 
-            NodeKind::Error(_, _) => Some(Category::Invalid),
-            NodeKind::Unknown(_) => Some(Category::Invalid),
+            NodeKind::Error(_, _) => Some(Category::Error),
         }
     }
 
     /// Return the TextMate grammar scope for the given highlighting category.
     pub fn tm_scope(&self) -> &'static str {
         match self {
-            Self::Bracket => "punctuation.definition.typst",
-            Self::Punctuation => "punctuation.typst",
             Self::Comment => "comment.typst",
-            Self::Shortcut => "punctuation.shortcut.typst",
-            Self::Escape => "constant.character.escape.content.typst",
+            Self::Bracket => "punctuation.definition.bracket.typst",
+            Self::Punctuation => "punctuation.typst",
+            Self::Escape => "constant.character.escape.typst",
+            Self::Shortcut => "constant.character.shortcut.typst",
+            Self::Quote => "constant.character.quote.typst",
             Self::Strong => "markup.bold.typst",
             Self::Emph => "markup.italic.typst",
             Self::Link => "markup.underline.link.typst",
             Self::Raw => "markup.raw.typst",
             Self::Math => "string.other.math.typst",
+            Self::MathDelimiter => "punctuation.definition.math.typst",
+            Self::MathSymbol => "keyword.operator.math.typst",
             Self::Heading => "markup.heading.typst",
-            Self::ListMarker => "markup.list.typst",
-            Self::Term => "markup.list.term.typst",
+            Self::ListItem => "markup.list.typst",
+            Self::ListMarker => "punctuation.definition.list.typst",
+            Self::ListTerm => "markup.list.term.typst",
             Self::Label => "entity.name.label.typst",
             Self::Ref => "markup.other.reference.typst",
             Self::Keyword => "keyword.typst",
             Self::Operator => "keyword.operator.typst",
-            Self::None => "constant.language.none.typst",
-            Self::Auto => "constant.language.auto.typst",
-            Self::Bool => "constant.language.boolean.typst",
+            Self::KeywordLiteral => "constant.language.typst",
             Self::Number => "constant.numeric.typst",
             Self::String => "string.quoted.double.typst",
             Self::Function => "entity.name.function.typst",
-            Self::Interpolated => "entity.other.interpolated.typst",
-            Self::Invalid => "invalid.typst",
+            Self::Interpolated => "meta.interpolation.typst",
+            Self::Error => "invalid.typst",
         }
     }
 }
@@ -428,7 +417,7 @@ mod tests {
             let mut vec = vec![];
             let source = Source::detached(text);
             let full = 0 .. text.len();
-            highlight_node(source.root(), full, &mut |range, category| {
+            highlight_categories(source.root(), full, &mut |range, category| {
                 vec.push((range, category));
             });
             assert_eq!(vec, goal);
diff --git a/src/syntax/kind.rs b/src/syntax/kind.rs
new file mode 100644
index 00000000..e76c93aa
--- /dev/null
+++ b/src/syntax/kind.rs
@@ -0,0 +1,548 @@
+use std::hash::{Hash, Hasher};
+use std::sync::Arc;
+
+use super::ast::{RawNode, Unit};
+use super::SpanPos;
+use crate::util::EcoString;
+
+/// All syntactical building blocks that can be part of a Typst document.
+///
+/// Can be emitted as a token by the tokenizer or as part of a syntax node by
+/// the parser.
+#[derive(Debug, Clone, PartialEq)]
+pub enum NodeKind {
+    /// A line comment, two slashes followed by inner contents, terminated with
+    /// a newline: `//<str>\n`.
+    LineComment,
+    /// A block comment, a slash and a star followed by inner contents,
+    /// terminated with a star and a slash: `/*<str>*/`.
+    ///
+    /// The comment can contain nested block comments.
+    BlockComment,
+    /// One or more whitespace characters. Single spaces are collapsed into text
+    /// nodes if they would otherwise be surrounded by text nodes.
+    ///
+    /// Also stores how many newlines are contained.
+    Space { newlines: usize },
+
+    /// A left curly brace, starting a code block: `{`.
+    LeftBrace,
+    /// A right curly brace, terminating a code block: `}`.
+    RightBrace,
+    /// A left square bracket, starting a content block: `[`.
+    LeftBracket,
+    /// A right square bracket, terminating a content block: `]`.
+    RightBracket,
+    /// A left round parenthesis, starting a grouped expression, collection,
+    /// argument or parameter list: `(`.
+    LeftParen,
+    /// A right round parenthesis, terminating a grouped expression, collection,
+    /// argument or parameter list: `)`.
+    RightParen,
+    /// A comma separator in a sequence: `,`.
+    Comma,
+    /// A semicolon terminating an expression: `;`.
+    Semicolon,
+    /// A colon between name / key and value in a dictionary, argument or
+    /// parameter list, or between the term and body of a description list
+    /// term: `:`.
+    Colon,
+    /// The strong text toggle, multiplication operator, and wildcard import
+    /// symbol: `*`.
+    Star,
+    /// Toggles emphasized text and indicates a subscript in a formula: `_`.
+    Underscore,
+    /// Starts and ends a math formula.
+    Dollar,
+    /// A forced line break: `\`.
+    Backslash,
+    /// The non-breaking space: `~`.
+    Tilde,
+    /// The soft hyphen: `-?`.
+    HyphQuest,
+    /// The en-dash: `--`.
+    Hyph2,
+    /// The em-dash: `---`.
+    Hyph3,
+    /// The ellipsis: `...`.
+    Dot3,
+    /// A smart quote: `'` or `"`.
+    Quote { double: bool },
+    /// The unary plus, binary addition operator, and start of enum items: `+`.
+    Plus,
+    /// The unary negation, binary subtraction operator, and start of list
+    /// items: `-`.
+    Minus,
+    /// The division operator, start of description list items, and fraction
+    /// operator in a formula: `/`.
+    Slash,
+    /// The superscript operator in a formula: `^`.
+    Hat,
+    /// The alignment operator in a formula: `&`.
+    Amp,
+    /// The field access and method call operator: `.`.
+    Dot,
+    /// The assignment operator: `=`.
+    Eq,
+    /// The equality operator: `==`.
+    EqEq,
+    /// The inequality operator: `!=`.
+    ExclEq,
+    /// The less-than operator: `<`.
+    Lt,
+    /// The less-than or equal operator: `<=`.
+    LtEq,
+    /// The greater-than operator: `>`.
+    Gt,
+    /// The greater-than or equal operator: `>=`.
+    GtEq,
+    /// The add-assign operator: `+=`.
+    PlusEq,
+    /// The subtract-assign operator: `-=`.
+    HyphEq,
+    /// The multiply-assign operator: `*=`.
+    StarEq,
+    /// The divide-assign operator: `/=`.
+    SlashEq,
+    /// The spread operator: `..`.
+    Dots,
+    /// An arrow between a closure's parameters and body: `=>`.
+    Arrow,
+
+    /// The `not` operator.
+    Not,
+    /// The `and` operator.
+    And,
+    /// The `or` operator.
+    Or,
+    /// The `none` literal.
+    None,
+    /// The `auto` literal.
+    Auto,
+    /// The `let` keyword.
+    Let,
+    /// The `set` keyword.
+    Set,
+    /// The `show` keyword.
+    Show,
+    /// The `wrap` keyword.
+    Wrap,
+    /// The `if` keyword.
+    If,
+    /// The `else` keyword.
+    Else,
+    /// The `for` keyword.
+    For,
+    /// The `in` keyword.
+    In,
+    /// The `while` keyword.
+    While,
+    /// The `break` keyword.
+    Break,
+    /// The `continue` keyword.
+    Continue,
+    /// The `return` keyword.
+    Return,
+    /// The `import` keyword.
+    Import,
+    /// The `include` keyword.
+    Include,
+    /// The `from` keyword.
+    From,
+    /// The `as` keyword.
+    As,
+
+    /// Markup of which all lines must have a minimal indentation.
+    ///
+    /// Notably, the number does not determine in which column the markup
+    /// started, but to the right of which column all markup elements must be,
+    /// so it is zero except inside indent-aware constructs like lists.
+    Markup { min_indent: usize },
+    /// Consecutive text without markup.
+    Text(EcoString),
+    /// A unicode escape sequence, written as a slash and the letter "u"
+    /// followed by a hexadecimal unicode entity enclosed in curly braces:
+    /// `\u{1F5FA}`.
+    Escape(char),
+    /// Strong content: `*Strong*`.
+    Strong,
+    /// Emphasized content: `_Emphasized_`.
+    Emph,
+    /// A hyperlink: `https://typst.org`.
+    Link(EcoString),
+    /// A raw block with optional syntax highlighting: `` `...` ``.
+    Raw(Arc<RawNode>),
+    /// A math formula: `$x$`, `$ x^2 $`.
+    Math,
+    /// An atom in a math formula: `x`, `+`, `12`.
+    Atom(EcoString),
+    /// A base with optional sub- and superscript in a math formula: `a_1^2`.
+    Script,
+    /// A fraction in a math formula: `x/2`.
+    Frac,
+    /// An alignment indicator in a math formula: `&`, `&&`.
+    Align,
+    /// A section heading: `= Introduction`.
+    Heading,
+    /// An item in an unordered list: `- ...`.
+    ListItem,
+    /// An item in an enumeration (ordered list): `+ ...` or `1. ...`.
+    EnumItem,
+    /// An explicit enumeration numbering: `23.`.
+    EnumNumbering(usize),
+    /// An item in a description list: `/ Term: Details.
+    DescItem,
+    /// A label: `<label>`.
+    Label(EcoString),
+    /// A reference: `@label`.
+    Ref(EcoString),
+
+    /// An identifier: `center`.
+    Ident(EcoString),
+    /// A boolean: `true`, `false`.
+    Bool(bool),
+    /// An integer: `120`.
+    Int(i64),
+    /// A floating-point number: `1.2`, `10e-4`.
+    Float(f64),
+    /// A numeric value with a unit: `12pt`, `3cm`, `2em`, `90deg`, `50%`.
+    Numeric(f64, Unit),
+    /// A quoted string: `"..."`.
+    Str(EcoString),
+    /// A code block: `{ let x = 1; x + 2 }`.
+    CodeBlock,
+    /// A content block: `[*Hi* there!]`.
+    ContentBlock,
+    /// A grouped expression: `(1 + 2)`.
+    GroupExpr,
+    /// An array expression: `(1, "hi", 12cm)`.
+    ArrayExpr,
+    /// A dictionary expression: `(thickness: 3pt, pattern: dashed)`.
+    DictExpr,
+    /// A named pair: `thickness: 3pt`.
+    Named,
+    /// A keyed pair: `"spacy key": true`.
+    Keyed,
+    /// A unary operation: `-x`.
+    UnaryExpr,
+    /// A binary operation: `a + b`.
+    BinaryExpr,
+    /// A field access: `properties.age`.
+    FieldAccess,
+    /// An invocation of a function: `f(x, y)`.
+    FuncCall,
+    /// An invocation of a method: `array.push(v)`.
+    MethodCall,
+    /// A function call's argument list: `(x, y)`.
+    CallArgs,
+    /// Spreaded arguments or a argument sink: `..x`.
+    Spread,
+    /// A closure expression: `(x, y) => z`.
+    ClosureExpr,
+    /// A closure's parameters: `(x, y)`.
+    ClosureParams,
+    /// A let expression: `let x = 1`.
+    LetExpr,
+    /// A set expression: `set text(...)`.
+    SetExpr,
+    /// A show expression: `show node: heading as [*{nody.body}*]`.
+    ShowExpr,
+    /// A wrap expression: `wrap body in columns(2, body)`.
+    WrapExpr,
+    /// An if-else expression: `if x { y } else { z }`.
+    IfExpr,
+    /// A while loop expression: `while x { ... }`.
+    WhileExpr,
+    /// A for loop expression: `for x in y { ... }`.
+    ForExpr,
+    /// A for loop's destructuring pattern: `x` or `x, y`.
+    ForPattern,
+    /// An import expression: `import a, b, c from "utils.typ"`.
+    ImportExpr,
+    /// Items to import: `a, b, c`.
+    ImportItems,
+    /// An include expression: `include "chapter1.typ"`.
+    IncludeExpr,
+    /// A break expression: `break`.
+    BreakExpr,
+    /// A continue expression: `continue`.
+    ContinueExpr,
+    /// A return expression: `return x + 1`.
+    ReturnExpr,
+
+    /// An invalid sequence of characters.
+    Error(SpanPos, EcoString),
+}
+
+impl NodeKind {
+    /// Whether this is a kind of parenthesis.
+    pub fn is_paren(&self) -> bool {
+        matches!(self, Self::LeftParen | Self::RightParen)
+    }
+
+    /// Whether this is a space.
+    pub fn is_space(&self) -> bool {
+        matches!(self, Self::Space { .. })
+    }
+
+    /// Whether this is trivia.
+    pub fn is_trivia(&self) -> bool {
+        self.is_space() || matches!(self, Self::LineComment | Self::BlockComment)
+    }
+
+    /// Whether this is a kind of error.
+    pub fn is_error(&self) -> bool {
+        matches!(self, NodeKind::Error(_, _))
+    }
+
+    /// A human-readable name for the kind.
+    pub fn name(&self) -> &'static str {
+        match self {
+            Self::LineComment => "line comment",
+            Self::BlockComment => "block comment",
+            Self::Space { .. } => "space",
+            Self::LeftBrace => "opening brace",
+            Self::RightBrace => "closing brace",
+            Self::LeftBracket => "opening bracket",
+            Self::RightBracket => "closing bracket",
+            Self::LeftParen => "opening paren",
+            Self::RightParen => "closing paren",
+            Self::Comma => "comma",
+            Self::Semicolon => "semicolon",
+            Self::Colon => "colon",
+            Self::Star => "star",
+            Self::Underscore => "underscore",
+            Self::Dollar => "dollar sign",
+            Self::Backslash => "linebreak",
+            Self::Tilde => "non-breaking space",
+            Self::HyphQuest => "soft hyphen",
+            Self::Hyph2 => "en dash",
+            Self::Hyph3 => "em dash",
+            Self::Dot3 => "ellipsis",
+            Self::Quote { double: false } => "single quote",
+            Self::Quote { double: true } => "double quote",
+            Self::Plus => "plus",
+            Self::Minus => "minus",
+            Self::Slash => "slash",
+            Self::Hat => "hat",
+            Self::Amp => "ampersand",
+            Self::Dot => "dot",
+            Self::Eq => "assignment operator",
+            Self::EqEq => "equality operator",
+            Self::ExclEq => "inequality operator",
+            Self::Lt => "less-than operator",
+            Self::LtEq => "less-than or equal operator",
+            Self::Gt => "greater-than operator",
+            Self::GtEq => "greater-than or equal operator",
+            Self::PlusEq => "add-assign operator",
+            Self::HyphEq => "subtract-assign operator",
+            Self::StarEq => "multiply-assign operator",
+            Self::SlashEq => "divide-assign operator",
+            Self::Dots => "dots",
+            Self::Arrow => "arrow",
+            Self::Not => "operator `not`",
+            Self::And => "operator `and`",
+            Self::Or => "operator `or`",
+            Self::None => "`none`",
+            Self::Auto => "`auto`",
+            Self::Let => "keyword `let`",
+            Self::Set => "keyword `set`",
+            Self::Show => "keyword `show`",
+            Self::Wrap => "keyword `wrap`",
+            Self::If => "keyword `if`",
+            Self::Else => "keyword `else`",
+            Self::For => "keyword `for`",
+            Self::In => "keyword `in`",
+            Self::While => "keyword `while`",
+            Self::Break => "keyword `break`",
+            Self::Continue => "keyword `continue`",
+            Self::Return => "keyword `return`",
+            Self::Import => "keyword `import`",
+            Self::Include => "keyword `include`",
+            Self::From => "keyword `from`",
+            Self::As => "keyword `as`",
+            Self::Markup { .. } => "markup",
+            Self::Text(_) => "text",
+            Self::Escape(_) => "escape sequence",
+            Self::Strong => "strong content",
+            Self::Emph => "emphasized content",
+            Self::Link(_) => "link",
+            Self::Raw(_) => "raw block",
+            Self::Math => "math formula",
+            Self::Atom(_) => "math atom",
+            Self::Script => "script",
+            Self::Frac => "fraction",
+            Self::Align => "alignment indicator",
+            Self::Heading => "heading",
+            Self::ListItem => "list item",
+            Self::EnumItem => "enumeration item",
+            Self::EnumNumbering(_) => "enumeration item numbering",
+            Self::DescItem => "description list item",
+            Self::Label(_) => "label",
+            Self::Ref(_) => "reference",
+            Self::Ident(_) => "identifier",
+            Self::Bool(_) => "boolean",
+            Self::Int(_) => "integer",
+            Self::Float(_) => "float",
+            Self::Numeric(_, _) => "numeric value",
+            Self::Str(_) => "string",
+            Self::CodeBlock => "code block",
+            Self::ContentBlock => "content block",
+            Self::GroupExpr => "group",
+            Self::ArrayExpr => "array",
+            Self::DictExpr => "dictionary",
+            Self::Named => "named pair",
+            Self::Keyed => "keyed pair",
+            Self::UnaryExpr => "unary expression",
+            Self::BinaryExpr => "binary expression",
+            Self::FieldAccess => "field access",
+            Self::FuncCall => "function call",
+            Self::MethodCall => "method call",
+            Self::CallArgs => "call arguments",
+            Self::Spread => "spread",
+            Self::ClosureExpr => "closure",
+            Self::ClosureParams => "closure parameters",
+            Self::LetExpr => "`let` expression",
+            Self::SetExpr => "`set` expression",
+            Self::ShowExpr => "`show` expression",
+            Self::WrapExpr => "`wrap` expression",
+            Self::IfExpr => "`if` expression",
+            Self::WhileExpr => "while-loop expression",
+            Self::ForExpr => "for-loop expression",
+            Self::ForPattern => "for-loop destructuring pattern",
+            Self::ImportExpr => "`import` expression",
+            Self::ImportItems => "import items",
+            Self::IncludeExpr => "`include` expression",
+            Self::BreakExpr => "`break` expression",
+            Self::ContinueExpr => "`continue` expression",
+            Self::ReturnExpr => "`return` expression",
+            Self::Error(_, _) => "syntax error",
+        }
+    }
+}
+
+impl Hash for NodeKind {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        std::mem::discriminant(self).hash(state);
+        match self {
+            Self::LineComment => {}
+            Self::BlockComment => {}
+            Self::Space { newlines } => newlines.hash(state),
+            Self::LeftBrace => {}
+            Self::RightBrace => {}
+            Self::LeftBracket => {}
+            Self::RightBracket => {}
+            Self::LeftParen => {}
+            Self::RightParen => {}
+            Self::Comma => {}
+            Self::Semicolon => {}
+            Self::Colon => {}
+            Self::Star => {}
+            Self::Underscore => {}
+            Self::Dollar => {}
+            Self::Backslash => {}
+            Self::Tilde => {}
+            Self::HyphQuest => {}
+            Self::Hyph2 => {}
+            Self::Hyph3 => {}
+            Self::Dot3 => {}
+            Self::Quote { double } => double.hash(state),
+            Self::Plus => {}
+            Self::Minus => {}
+            Self::Slash => {}
+            Self::Hat => {}
+            Self::Amp => {}
+            Self::Dot => {}
+            Self::Eq => {}
+            Self::EqEq => {}
+            Self::ExclEq => {}
+            Self::Lt => {}
+            Self::LtEq => {}
+            Self::Gt => {}
+            Self::GtEq => {}
+            Self::PlusEq => {}
+            Self::HyphEq => {}
+            Self::StarEq => {}
+            Self::SlashEq => {}
+            Self::Dots => {}
+            Self::Arrow => {}
+            Self::Not => {}
+            Self::And => {}
+            Self::Or => {}
+            Self::None => {}
+            Self::Auto => {}
+            Self::Let => {}
+            Self::Set => {}
+            Self::Show => {}
+            Self::Wrap => {}
+            Self::If => {}
+            Self::Else => {}
+            Self::For => {}
+            Self::In => {}
+            Self::While => {}
+            Self::Break => {}
+            Self::Continue => {}
+            Self::Return => {}
+            Self::Import => {}
+            Self::Include => {}
+            Self::From => {}
+            Self::As => {}
+            Self::Markup { min_indent } => min_indent.hash(state),
+            Self::Text(s) => s.hash(state),
+            Self::Escape(c) => c.hash(state),
+            Self::Strong => {}
+            Self::Emph => {}
+            Self::Link(link) => link.hash(state),
+            Self::Raw(raw) => raw.hash(state),
+            Self::Math => {}
+            Self::Atom(c) => c.hash(state),
+            Self::Script => {}
+            Self::Frac => {}
+            Self::Align => {}
+            Self::Heading => {}
+            Self::ListItem => {}
+            Self::EnumItem => {}
+            Self::EnumNumbering(num) => num.hash(state),
+            Self::DescItem => {}
+            Self::Label(c) => c.hash(state),
+            Self::Ref(c) => c.hash(state),
+            Self::Ident(v) => v.hash(state),
+            Self::Bool(v) => v.hash(state),
+            Self::Int(v) => v.hash(state),
+            Self::Float(v) => v.to_bits().hash(state),
+            Self::Numeric(v, u) => (v.to_bits(), u).hash(state),
+            Self::Str(v) => v.hash(state),
+            Self::CodeBlock => {}
+            Self::ContentBlock => {}
+            Self::GroupExpr => {}
+            Self::ArrayExpr => {}
+            Self::DictExpr => {}
+            Self::Named => {}
+            Self::Keyed => {}
+            Self::UnaryExpr => {}
+            Self::BinaryExpr => {}
+            Self::FieldAccess => {}
+            Self::FuncCall => {}
+            Self::MethodCall => {}
+            Self::CallArgs => {}
+            Self::Spread => {}
+            Self::ClosureExpr => {}
+            Self::ClosureParams => {}
+            Self::LetExpr => {}
+            Self::SetExpr => {}
+            Self::ShowExpr => {}
+            Self::WrapExpr => {}
+            Self::IfExpr => {}
+            Self::WhileExpr => {}
+            Self::ForExpr => {}
+            Self::ForPattern => {}
+            Self::ImportExpr => {}
+            Self::ImportItems => {}
+            Self::IncludeExpr => {}
+            Self::BreakExpr => {}
+            Self::ContinueExpr => {}
+            Self::ReturnExpr => {}
+            Self::Error(pos, msg) => (pos, msg).hash(state),
+        }
+    }
+}
diff --git a/src/syntax/mod.rs b/src/syntax/mod.rs
index 367d0062..5ff99d03 100644
--- a/src/syntax/mod.rs
+++ b/src/syntax/mod.rs
@@ -1,21 +1,20 @@
 //! Syntax types.
 
 pub mod ast;
-mod highlight;
+pub mod highlight;
+mod kind;
 mod span;
 
-use std::fmt::{self, Debug, Display, Formatter};
-use std::hash::{Hash, Hasher};
+use std::fmt::{self, Debug, Formatter};
 use std::ops::Range;
 use std::sync::Arc;
 
-pub use highlight::*;
+pub use kind::*;
 pub use span::*;
 
-use self::ast::{RawNode, TypedNode, Unit};
+use self::ast::TypedNode;
 use crate::diag::SourceError;
 use crate::source::SourceId;
-use crate::util::EcoString;
 
 /// An inner or leaf node in the untyped syntax tree.
 #[derive(Clone, PartialEq, Hash)]
@@ -73,8 +72,8 @@ impl SyntaxNode {
         }
 
         match self.kind() {
-            &NodeKind::Error(pos, ref message) => {
-                vec![SourceError::new(self.span().with_pos(pos), message)]
+            NodeKind::Error(pos, message) => {
+                vec![SourceError::new(self.span().with_pos(*pos), message)]
             }
             _ => self
                 .children()
@@ -564,602 +563,3 @@ impl PartialEq for NodeData {
         self.kind == other.kind && self.len == other.len
     }
 }
-
-/// All syntactical building blocks that can be part of a Typst document.
-///
-/// Can be emitted as a token by the tokenizer or as part of a syntax node by
-/// the parser.
-#[derive(Debug, Clone, PartialEq)]
-pub enum NodeKind {
-    /// A line comment, two slashes followed by inner contents, terminated with
-    /// a newline: `//<str>\n`.
-    LineComment,
-    /// A block comment, a slash and a star followed by inner contents,
-    /// terminated with a star and a slash: `/*<str>*/`.
-    ///
-    /// The comment can contain nested block comments.
-    BlockComment,
-    /// One or more whitespace characters. Single spaces are collapsed into text
-    /// nodes if they would otherwise be surrounded by text nodes.
-    ///
-    /// Also stores how many newlines are contained.
-    Space { newlines: usize },
-
-    /// A left curly brace, starting a code block: `{`.
-    LeftBrace,
-    /// A right curly brace, terminating a code block: `}`.
-    RightBrace,
-    /// A left square bracket, starting a content block: `[`.
-    LeftBracket,
-    /// A right square bracket, terminating a content block: `]`.
-    RightBracket,
-    /// A left round parenthesis, starting a grouped expression, collection,
-    /// argument or parameter list: `(`.
-    LeftParen,
-    /// A right round parenthesis, terminating a grouped expression, collection,
-    /// argument or parameter list: `)`.
-    RightParen,
-    /// A comma separator in a sequence: `,`.
-    Comma,
-    /// A semicolon terminating an expression: `;`.
-    Semicolon,
-    /// A colon between name / key and value in a dictionary, argument or
-    /// parameter list, or between the term and body of a description list
-    /// term: `:`.
-    Colon,
-    /// The strong text toggle, multiplication operator, and wildcard import
-    /// symbol: `*`.
-    Star,
-    /// Toggles emphasized text and indicates a subscript in a formula: `_`.
-    Underscore,
-    /// Starts and ends a math formula.
-    Dollar,
-    /// The non-breaking space: `~`.
-    Tilde,
-    /// The soft hyphen: `-?`.
-    HyphQuest,
-    /// The en-dash: `--`.
-    Hyph2,
-    /// The em-dash: `---`.
-    Hyph3,
-    /// The ellipsis: `...`.
-    Dot3,
-    /// A smart quote: `'` or `"`.
-    Quote { double: bool },
-    /// The unary plus and addition operator, and start of enum items: `+`.
-    Plus,
-    /// The unary negation and subtraction operator, and start of list
-    /// items: `-`.
-    Minus,
-    /// The division operator, start of description list items, and fraction
-    /// operator in a formula: `/`.
-    Slash,
-    /// The superscript operator: `^`.
-    Hat,
-    /// The math alignment operator: `&`.
-    Amp,
-    /// The field access and method call operator: `.`.
-    Dot,
-    /// The assignment operator: `=`.
-    Eq,
-    /// The equality operator: `==`.
-    EqEq,
-    /// The inequality operator: `!=`.
-    ExclEq,
-    /// The less-than operator: `<`.
-    Lt,
-    /// The less-than or equal operator: `<=`.
-    LtEq,
-    /// The greater-than operator: `>`.
-    Gt,
-    /// The greater-than or equal operator: `>=`.
-    GtEq,
-    /// The add-assign operator: `+=`.
-    PlusEq,
-    /// The subtract-assign operator: `-=`.
-    HyphEq,
-    /// The multiply-assign operator: `*=`.
-    StarEq,
-    /// The divide-assign operator: `/=`.
-    SlashEq,
-    /// The spread operator: `..`.
-    Dots,
-    /// An arrow between a closure's parameters and body: `=>`.
-    Arrow,
-
-    /// The `not` operator.
-    Not,
-    /// The `and` operator.
-    And,
-    /// The `or` operator.
-    Or,
-    /// The `none` literal.
-    None,
-    /// The `auto` literal.
-    Auto,
-    /// The `let` keyword.
-    Let,
-    /// The `set` keyword.
-    Set,
-    /// The `show` keyword.
-    Show,
-    /// The `wrap` keyword.
-    Wrap,
-    /// The `if` keyword.
-    If,
-    /// The `else` keyword.
-    Else,
-    /// The `for` keyword.
-    For,
-    /// The `in` keyword.
-    In,
-    /// The `while` keyword.
-    While,
-    /// The `break` keyword.
-    Break,
-    /// The `continue` keyword.
-    Continue,
-    /// The `return` keyword.
-    Return,
-    /// The `import` keyword.
-    Import,
-    /// The `include` keyword.
-    Include,
-    /// The `from` keyword.
-    From,
-    /// The `as` keyword.
-    As,
-
-    /// Markup of which all lines must have a minimal indentation.
-    ///
-    /// Notably, the number does not determine in which column the markup
-    /// started, but to the right of which column all markup elements must be,
-    /// so it is zero except for headings and lists.
-    Markup { min_indent: usize },
-    /// A forced line break in markup or math.
-    Linebreak,
-    /// Consecutive text without markup. While basic text with just single
-    /// spaces is collapsed into a single node, certain symbols that could
-    /// possibly be markup force text into multiple nodes.
-    Text(EcoString),
-    /// A slash and the letter "u" followed by a hexadecimal unicode entity
-    /// enclosed in curly braces: `\u{1F5FA}`.
-    Escape(char),
-    /// Strong content: `*Strong*`.
-    Strong,
-    /// Emphasized content: `_Emphasized_`.
-    Emph,
-    /// A hyperlink.
-    Link(EcoString),
-    /// A raw block with optional syntax highlighting: `` `...` ``.
-    Raw(Arc<RawNode>),
-    /// A math formula: `$x$`, `$ x^2 $`.
-    Math,
-    /// A section heading: `= Introduction`.
-    Heading,
-    /// An item in an unordered list: `- ...`.
-    List,
-    /// An item in an enumeration (ordered list): `+ ...` or `1. ...`.
-    Enum,
-    /// An explicit enumeration numbering: `23.`.
-    EnumNumbering(usize),
-    /// An item in a description list: `/ Term: Details.
-    Desc,
-    /// A label: `<label>`.
-    Label(EcoString),
-    /// A reference: `@label`.
-    Ref(EcoString),
-
-    /// An atom in a math formula: `x`, `+`, `12`.
-    Atom(EcoString),
-    /// A base with an optional sub- and superscript in a formula: `a_1^2`.
-    Script,
-    /// A fraction: `x/2`.
-    Frac,
-    /// A math alignment indicator: `&`, `&&`.
-    Align,
-
-    /// An identifier: `center`.
-    Ident(EcoString),
-    /// A boolean: `true`, `false`.
-    Bool(bool),
-    /// An integer: `120`.
-    Int(i64),
-    /// A floating-point number: `1.2`, `10e-4`.
-    Float(f64),
-    /// A numeric value with a unit: `12pt`, `3cm`, `2em`, `90deg`, `50%`.
-    Numeric(f64, Unit),
-    /// A quoted string: `"..."`.
-    Str(EcoString),
-    /// A code block: `{ let x = 1; x + 2 }`.
-    CodeBlock,
-    /// A content block: `[*Hi* there!]`.
-    ContentBlock,
-    /// A grouped expression: `(1 + 2)`.
-    GroupExpr,
-    /// An array expression: `(1, "hi", 12cm)`.
-    ArrayExpr,
-    /// A dictionary expression: `(thickness: 3pt, pattern: dashed)`.
-    DictExpr,
-    /// A named pair: `thickness: 3pt`.
-    Named,
-    /// A keyed pair: `"spacy key": true`.
-    Keyed,
-    /// A unary operation: `-x`.
-    UnaryExpr,
-    /// A binary operation: `a + b`.
-    BinaryExpr,
-    /// A field access: `properties.age`.
-    FieldAccess,
-    /// An invocation of a function: `f(x, y)`.
-    FuncCall,
-    /// An invocation of a method: `array.push(v)`.
-    MethodCall,
-    /// A function call's argument list: `(x, y)`.
-    CallArgs,
-    /// Spreaded arguments or a argument sink: `..x`.
-    Spread,
-    /// A closure expression: `(x, y) => z`.
-    ClosureExpr,
-    /// A closure's parameters: `(x, y)`.
-    ClosureParams,
-    /// A let expression: `let x = 1`.
-    LetExpr,
-    /// A set expression: `set text(...)`.
-    SetExpr,
-    /// A show expression: `show node: heading as [*{nody.body}*]`.
-    ShowExpr,
-    /// A wrap expression: `wrap body in columns(2, body)`.
-    WrapExpr,
-    /// An if-else expression: `if x { y } else { z }`.
-    IfExpr,
-    /// A while loop expression: `while x { ... }`.
-    WhileExpr,
-    /// A for loop expression: `for x in y { ... }`.
-    ForExpr,
-    /// A for loop's destructuring pattern: `x` or `x, y`.
-    ForPattern,
-    /// An import expression: `import a, b, c from "utils.typ"`.
-    ImportExpr,
-    /// Items to import: `a, b, c`.
-    ImportItems,
-    /// An include expression: `include "chapter1.typ"`.
-    IncludeExpr,
-    /// A break expression: `break`.
-    BreakExpr,
-    /// A continue expression: `continue`.
-    ContinueExpr,
-    /// A return expression: `return x + 1`.
-    ReturnExpr,
-
-    /// Tokens that appear in the wrong place.
-    Error(SpanPos, EcoString),
-    /// Unknown character sequences.
-    Unknown(EcoString),
-}
-
-impl NodeKind {
-    /// Whether this is a kind of parenthesis.
-    pub fn is_paren(&self) -> bool {
-        matches!(self, Self::LeftParen | Self::RightParen)
-    }
-
-    /// Whether this is a space.
-    pub fn is_space(&self) -> bool {
-        matches!(self, Self::Space { .. })
-    }
-
-    /// Whether this is trivia.
-    pub fn is_trivia(&self) -> bool {
-        self.is_space() || matches!(self, Self::LineComment | Self::BlockComment)
-    }
-
-    /// Whether this is a kind of error.
-    pub fn is_error(&self) -> bool {
-        matches!(self, NodeKind::Error(_, _) | NodeKind::Unknown(_))
-    }
-
-    /// Whether `at_start` would still be true after this node given the
-    /// previous value of the property.
-    pub fn is_at_start(&self, prev: bool) -> bool {
-        match self {
-            Self::Space { newlines: (1 ..) } => true,
-            Self::Space { .. } | Self::LineComment | Self::BlockComment => prev,
-            _ => false,
-        }
-    }
-
-    /// Whether changes _inside_ this node are safely encapsulated, so that only
-    /// this node must be reparsed.
-    pub fn is_bounded(&self) -> bool {
-        match self {
-            Self::CodeBlock
-            | Self::ContentBlock
-            | Self::Linebreak { .. }
-            | Self::Tilde
-            | Self::HyphQuest
-            | Self::Hyph2
-            | Self::Hyph3
-            | Self::Dot3
-            | Self::Quote { .. }
-            | Self::BlockComment
-            | Self::Space { .. }
-            | Self::Escape(_) => true,
-            _ => false,
-        }
-    }
-
-    /// A human-readable name for the kind.
-    pub fn as_str(&self) -> &'static str {
-        match self {
-            Self::LineComment => "line comment",
-            Self::BlockComment => "block comment",
-            Self::Space { .. } => "space",
-
-            Self::LeftBrace => "opening brace",
-            Self::RightBrace => "closing brace",
-            Self::LeftBracket => "opening bracket",
-            Self::RightBracket => "closing bracket",
-            Self::LeftParen => "opening paren",
-            Self::RightParen => "closing paren",
-            Self::Comma => "comma",
-            Self::Semicolon => "semicolon",
-            Self::Colon => "colon",
-            Self::Star => "star",
-            Self::Underscore => "underscore",
-            Self::Dollar => "dollar sign",
-            Self::Tilde => "non-breaking space",
-            Self::HyphQuest => "soft hyphen",
-            Self::Hyph2 => "en dash",
-            Self::Hyph3 => "em dash",
-            Self::Dot3 => "ellipsis",
-            Self::Quote { double: false } => "single quote",
-            Self::Quote { double: true } => "double quote",
-            Self::Plus => "plus",
-            Self::Minus => "minus",
-            Self::Slash => "slash",
-            Self::Hat => "hat",
-            Self::Amp => "ampersand",
-            Self::Dot => "dot",
-            Self::Eq => "assignment operator",
-            Self::EqEq => "equality operator",
-            Self::ExclEq => "inequality operator",
-            Self::Lt => "less-than operator",
-            Self::LtEq => "less-than or equal operator",
-            Self::Gt => "greater-than operator",
-            Self::GtEq => "greater-than or equal operator",
-            Self::PlusEq => "add-assign operator",
-            Self::HyphEq => "subtract-assign operator",
-            Self::StarEq => "multiply-assign operator",
-            Self::SlashEq => "divide-assign operator",
-            Self::Dots => "dots",
-            Self::Arrow => "arrow",
-
-            Self::Not => "operator `not`",
-            Self::And => "operator `and`",
-            Self::Or => "operator `or`",
-            Self::None => "`none`",
-            Self::Auto => "`auto`",
-            Self::Let => "keyword `let`",
-            Self::Set => "keyword `set`",
-            Self::Show => "keyword `show`",
-            Self::Wrap => "keyword `wrap`",
-            Self::If => "keyword `if`",
-            Self::Else => "keyword `else`",
-            Self::For => "keyword `for`",
-            Self::In => "keyword `in`",
-            Self::While => "keyword `while`",
-            Self::Break => "keyword `break`",
-            Self::Continue => "keyword `continue`",
-            Self::Return => "keyword `return`",
-            Self::Import => "keyword `import`",
-            Self::Include => "keyword `include`",
-            Self::From => "keyword `from`",
-            Self::As => "keyword `as`",
-
-            Self::Markup { .. } => "markup",
-            Self::Linebreak => "linebreak",
-            Self::Text(_) => "text",
-            Self::Escape(_) => "escape sequence",
-            Self::Strong => "strong content",
-            Self::Emph => "emphasized content",
-            Self::Link(_) => "link",
-            Self::Raw(_) => "raw block",
-            Self::Math => "math formula",
-            Self::Heading => "heading",
-            Self::List => "list item",
-            Self::Enum => "enumeration item",
-            Self::EnumNumbering(_) => "enumeration item numbering",
-            Self::Desc => "description list item",
-            Self::Label(_) => "label",
-            Self::Ref(_) => "reference",
-
-            Self::Atom(_) => "math atom",
-            Self::Script => "script",
-            Self::Frac => "fraction",
-            Self::Align => "alignment indicator",
-
-            Self::Ident(_) => "identifier",
-            Self::Bool(_) => "boolean",
-            Self::Int(_) => "integer",
-            Self::Float(_) => "float",
-            Self::Numeric(_, _) => "numeric value",
-            Self::Str(_) => "string",
-            Self::CodeBlock => "code block",
-            Self::ContentBlock => "content block",
-            Self::GroupExpr => "group",
-            Self::ArrayExpr => "array",
-            Self::DictExpr => "dictionary",
-            Self::Named => "named pair",
-            Self::Keyed => "keyed pair",
-            Self::UnaryExpr => "unary expression",
-            Self::BinaryExpr => "binary expression",
-            Self::FieldAccess => "field access",
-            Self::FuncCall => "function call",
-            Self::MethodCall => "method call",
-            Self::CallArgs => "call arguments",
-            Self::Spread => "spread",
-            Self::ClosureExpr => "closure",
-            Self::ClosureParams => "closure parameters",
-            Self::LetExpr => "`let` expression",
-            Self::SetExpr => "`set` expression",
-            Self::ShowExpr => "`show` expression",
-            Self::WrapExpr => "`wrap` expression",
-            Self::IfExpr => "`if` expression",
-            Self::WhileExpr => "while-loop expression",
-            Self::ForExpr => "for-loop expression",
-            Self::ForPattern => "for-loop destructuring pattern",
-            Self::ImportExpr => "`import` expression",
-            Self::ImportItems => "import items",
-            Self::IncludeExpr => "`include` expression",
-            Self::BreakExpr => "`break` expression",
-            Self::ContinueExpr => "`continue` expression",
-            Self::ReturnExpr => "`return` expression",
-
-            Self::Error(_, _) => "parse error",
-            Self::Unknown(text) => match text.as_str() {
-                "*/" => "end of block comment",
-                _ => "invalid token",
-            },
-        }
-    }
-}
-
-impl Display for NodeKind {
-    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        f.pad(self.as_str())
-    }
-}
-
-impl Hash for NodeKind {
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        std::mem::discriminant(self).hash(state);
-        match self {
-            Self::LineComment => {}
-            Self::BlockComment => {}
-            Self::Space { newlines } => newlines.hash(state),
-
-            Self::LeftBrace => {}
-            Self::RightBrace => {}
-            Self::LeftBracket => {}
-            Self::RightBracket => {}
-            Self::LeftParen => {}
-            Self::RightParen => {}
-            Self::Comma => {}
-            Self::Semicolon => {}
-            Self::Colon => {}
-            Self::Star => {}
-            Self::Underscore => {}
-            Self::Dollar => {}
-            Self::Tilde => {}
-            Self::HyphQuest => {}
-            Self::Hyph2 => {}
-            Self::Hyph3 => {}
-            Self::Dot3 => {}
-            Self::Quote { double } => double.hash(state),
-            Self::Plus => {}
-            Self::Minus => {}
-            Self::Slash => {}
-            Self::Hat => {}
-            Self::Amp => {}
-            Self::Dot => {}
-            Self::Eq => {}
-            Self::EqEq => {}
-            Self::ExclEq => {}
-            Self::Lt => {}
-            Self::LtEq => {}
-            Self::Gt => {}
-            Self::GtEq => {}
-            Self::PlusEq => {}
-            Self::HyphEq => {}
-            Self::StarEq => {}
-            Self::SlashEq => {}
-            Self::Dots => {}
-            Self::Arrow => {}
-
-            Self::Not => {}
-            Self::And => {}
-            Self::Or => {}
-            Self::None => {}
-            Self::Auto => {}
-            Self::Let => {}
-            Self::Set => {}
-            Self::Show => {}
-            Self::Wrap => {}
-            Self::If => {}
-            Self::Else => {}
-            Self::For => {}
-            Self::In => {}
-            Self::While => {}
-            Self::Break => {}
-            Self::Continue => {}
-            Self::Return => {}
-            Self::Import => {}
-            Self::Include => {}
-            Self::From => {}
-            Self::As => {}
-
-            Self::Markup { min_indent } => min_indent.hash(state),
-            Self::Linebreak => {}
-            Self::Text(s) => s.hash(state),
-            Self::Escape(c) => c.hash(state),
-            Self::Strong => {}
-            Self::Emph => {}
-            Self::Link(link) => link.hash(state),
-            Self::Raw(raw) => raw.hash(state),
-            Self::Math => {}
-            Self::Heading => {}
-            Self::List => {}
-            Self::Enum => {}
-            Self::EnumNumbering(num) => num.hash(state),
-            Self::Desc => {}
-            Self::Label(c) => c.hash(state),
-            Self::Ref(c) => c.hash(state),
-
-            Self::Atom(c) => c.hash(state),
-            Self::Script => {}
-            Self::Frac => {}
-            Self::Align => {}
-
-            Self::Ident(v) => v.hash(state),
-            Self::Bool(v) => v.hash(state),
-            Self::Int(v) => v.hash(state),
-            Self::Float(v) => v.to_bits().hash(state),
-            Self::Numeric(v, u) => (v.to_bits(), u).hash(state),
-            Self::Str(v) => v.hash(state),
-            Self::CodeBlock => {}
-            Self::ContentBlock => {}
-            Self::GroupExpr => {}
-            Self::ArrayExpr => {}
-            Self::DictExpr => {}
-            Self::Named => {}
-            Self::Keyed => {}
-            Self::UnaryExpr => {}
-            Self::BinaryExpr => {}
-            Self::FieldAccess => {}
-            Self::FuncCall => {}
-            Self::MethodCall => {}
-            Self::CallArgs => {}
-            Self::Spread => {}
-            Self::ClosureExpr => {}
-            Self::ClosureParams => {}
-            Self::LetExpr => {}
-            Self::SetExpr => {}
-            Self::ShowExpr => {}
-            Self::WrapExpr => {}
-            Self::IfExpr => {}
-            Self::WhileExpr => {}
-            Self::ForExpr => {}
-            Self::ForPattern => {}
-            Self::ImportExpr => {}
-            Self::ImportItems => {}
-            Self::IncludeExpr => {}
-            Self::BreakExpr => {}
-            Self::ContinueExpr => {}
-            Self::ReturnExpr => {}
-
-            Self::Error(pos, msg) => (pos, msg).hash(state),
-            Self::Unknown(text) => text.hash(state),
-        }
-    }
-}