Braced content -> Bracketed templates ✏

10 files changed, 175 insertions, 187 deletions

diff --git a/src/eval/mod.rs b/src/eval/mod.rs
index 403fa58f..efa74596 100644
--- a/src/eval/mod.rs
+++ b/src/eval/mod.rs
@@ -170,7 +170,7 @@ impl Eval for Spanned<&Expr> {
             Expr::Binary(v) => v.with_span(self.span).eval(ctx),
             Expr::Array(v) => Value::Array(v.with_span(self.span).eval(ctx)),
             Expr::Dict(v) => Value::Dict(v.with_span(self.span).eval(ctx)),
-            Expr::Content(v) => Value::Content(v.clone()),
+            Expr::Template(v) => Value::Template(v.clone()),
         }
     }
 }
@@ -275,7 +275,7 @@ fn add(ctx: &mut EvalContext, span: Span, lhs: Value, rhs: Value) -> Value {
         (Str(a), Str(b)) => Str(a + &b),
         (Array(a), Array(b)) => Array(concat(a, b)),
         (Dict(a), Dict(b)) => Dict(concat(a, b)),
-        (Content(a), Content(b)) => Content(concat(a, b)),
+        (Template(a), Template(b)) => Template(concat(a, b)),
 
         (a, b) => {
             ctx.diag(error!(
diff --git a/src/eval/value.rs b/src/eval/value.rs
index 67c468b0..d3b2688b 100644
--- a/src/eval/value.rs
+++ b/src/eval/value.rs
@@ -8,7 +8,7 @@ use super::{Args, Eval, EvalContext};
 use crate::color::Color;
 use crate::geom::{Angle, Length, Linear, Relative};
 use crate::pretty::{pretty, Pretty, Printer};
-use crate::syntax::{pretty_content_expr, Spanned, Tree, WithSpan};
+use crate::syntax::{pretty_template_expr, Spanned, Tree, WithSpan};
 
 /// A computational value.
 #[derive(Debug, Clone, PartialEq)]
@@ -37,8 +37,8 @@ pub enum Value {
     Array(ValueArray),
     /// A dictionary value: `(color: #f79143, pattern: dashed)`.
     Dict(ValueDict),
-    /// A content value: `{*Hi* there}`.
-    Content(ValueContent),
+    /// A template value: `[*Hi* there]`.
+    Template(ValueTemplate),
     /// An executable function.
     Func(ValueFunc),
     /// Any object.
@@ -71,7 +71,7 @@ impl Value {
             Self::Str(_) => String::TYPE_NAME,
             Self::Array(_) => ValueArray::TYPE_NAME,
             Self::Dict(_) => ValueDict::TYPE_NAME,
-            Self::Content(_) => ValueContent::TYPE_NAME,
+            Self::Template(_) => ValueTemplate::TYPE_NAME,
             Self::Func(_) => ValueFunc::TYPE_NAME,
             Self::Any(v) => v.type_name(),
             Self::Error => "error",
@@ -87,7 +87,7 @@ impl Eval for &Value {
         ctx.push(ctx.make_text_node(match self {
             Value::None => return,
             Value::Str(s) => s.clone(),
-            Value::Content(tree) => return tree.eval(ctx),
+            Value::Template(tree) => return tree.eval(ctx),
             other => pretty(other),
         }));
     }
@@ -114,7 +114,7 @@ impl Pretty for Value {
             Value::Str(v) => write!(p, "{:?}", v).unwrap(),
             Value::Array(array) => array.pretty(p),
             Value::Dict(dict) => dict.pretty(p),
-            Value::Content(content) => pretty_content_expr(content, p),
+            Value::Template(template) => pretty_template_expr(template, p),
             Value::Func(v) => v.pretty(p),
             Value::Any(v) => v.pretty(p),
             Value::Error => p.push_str("(error)"),
@@ -155,8 +155,8 @@ impl Pretty for ValueDict {
     }
 }
 
-/// A content value: `{*Hi* there}`.
-pub type ValueContent = Tree;
+/// A template value: `[*Hi* there]`.
+pub type ValueTemplate = Tree;
 
 /// A wrapper around a reference-counted executable function.
 #[derive(Clone)]
@@ -407,28 +407,26 @@ macro_rules! impl_primitive {
 
 impl_primitive! { bool: "boolean", Value::Bool }
 impl_primitive! { i64: "integer", Value::Int }
-impl_primitive! { Length: "length", Value::Length }
-impl_primitive! { Angle: "angle", Value::Angle }
-impl_primitive! { Relative: "relative", Value::Relative }
-impl_primitive! { Color: "color", Value::Color }
-impl_primitive! { String: "string", Value::Str }
-impl_primitive! { ValueArray: "array", Value::Array }
-impl_primitive! { ValueDict: "dictionary", Value::Dict }
-impl_primitive! { ValueContent: "content", Value::Content }
-impl_primitive! { ValueFunc: "function", Value::Func }
-
 impl_primitive! {
     f64: "float",
     Value::Float,
     Value::Int(v) => v as f64,
 }
-
+impl_primitive! { Length: "length", Value::Length }
+impl_primitive! { Angle: "angle", Value::Angle }
+impl_primitive! { Relative: "relative", Value::Relative }
 impl_primitive! {
     Linear: "linear",
     Value::Linear,
     Value::Length(v) => v.into(),
     Value::Relative(v) => v.into(),
 }
+impl_primitive! { Color: "color", Value::Color }
+impl_primitive! { String: "string", Value::Str }
+impl_primitive! { ValueArray: "array", Value::Array }
+impl_primitive! { ValueDict: "dictionary", Value::Dict }
+impl_primitive! { ValueTemplate: "template", Value::Template }
+impl_primitive! { ValueFunc: "function", Value::Func }
 
 impl From<&str> for Value {
     fn from(v: &str) -> Self {
@@ -512,7 +510,7 @@ mod tests {
         test_pretty(Relative::new(0.3) + Length::cm(2.0), "30% + 2cm");
         test_pretty(Color::Rgba(RgbaColor::new(1, 1, 1, 0xff)), "#010101");
         test_pretty("hello", r#""hello""#);
-        test_pretty(vec![Spanned::zero(Node::Strong)], "{*}");
+        test_pretty(vec![Spanned::zero(Node::Strong)], "[*]");
         test_pretty(ValueFunc::new("nil", |_, _| Value::None), "(function nil)");
         test_pretty(ValueAny::new(1), "1");
         test_pretty(Value::Error, "(error)");
@@ -528,8 +526,8 @@ mod tests {
         // Dictionary.
         let mut dict = BTreeMap::new();
         dict.insert("one".into(), Value::Int(1));
-        dict.insert("two".into(), Value::Content(parse("[f]").output));
+        dict.insert("two".into(), Value::Template(parse("[f]").output));
         test_pretty(BTreeMap::new(), "(:)");
-        test_pretty(dict, "(one: 1, two: [f])");
+        test_pretty(dict, "(one: 1, two: [[f]])");
     }
 }
diff --git a/src/library/layout.rs b/src/library/layout.rs
index 774e6781..59c1954b 100644
--- a/src/library/layout.rs
+++ b/src/library/layout.rs
@@ -101,7 +101,7 @@ pub fn align(ctx: &mut EvalContext, args: &mut Args) -> Value {
         ctx.start_par_group();
     }
 
-    if let Some(body) = args.find::<ValueContent>(ctx) {
+    if let Some(body) = args.find::<ValueTemplate>(ctx) {
         body.eval(ctx);
         ctx.state = snapshot;
     }
@@ -190,7 +190,7 @@ pub fn box_(ctx: &mut EvalContext, args: &mut Args) -> Value {
 
     ctx.start_content_group();
 
-    if let Some(body) = args.find::<ValueContent>(ctx) {
+    if let Some(body) = args.find::<ValueTemplate>(ctx) {
         body.eval(ctx);
     }
 
@@ -317,7 +317,7 @@ pub fn page(ctx: &mut EvalContext, args: &mut Args) -> Value {
     ctx.set_dirs(Gen::new(main, cross));
 
     let mut softness = ctx.end_page_group(|_| false);
-    if let Some(body) = args.find::<ValueContent>(ctx) {
+    if let Some(body) = args.find::<ValueTemplate>(ctx) {
         // TODO: Restrict body to a single page?
         ctx.start_page_group(Softness::Hard);
         body.eval(ctx);
diff --git a/src/library/style.rs b/src/library/style.rs
index 3bdcdfd4..7b2772cc 100644
--- a/src/library/style.rs
+++ b/src/library/style.rs
@@ -95,7 +95,7 @@ pub fn font(ctx: &mut EvalContext, args: &mut Args) -> Value {
         }
     }
 
-    if let Some(body) = args.find::<ValueContent>(ctx) {
+    if let Some(body) = args.find::<ValueTemplate>(ctx) {
         body.eval(ctx);
         ctx.state = snapshot;
     }
diff --git a/src/parse/mod.rs b/src/parse/mod.rs
index cce34d8a..ee799159 100644
--- a/src/parse/mod.rs
+++ b/src/parse/mod.rs
@@ -49,32 +49,20 @@ fn tree(p: &mut Parser) -> Tree {
 /// Parse a syntax node.
 fn node(p: &mut Parser, at_start: bool) -> Option<Node> {
     let node = match p.peek()? {
-        Token::Text(text) => Node::Text(text.into()),
-        Token::Space(newlines) => {
-            if newlines < 2 {
-                Node::Space
-            } else {
-                Node::Parbreak
-            }
-        }
-
-        Token::LineComment(_) | Token::BlockComment(_) => {
-            p.eat();
-            return None;
-        }
-
+        // Bracket call.
         Token::LeftBracket => {
             return Some(Node::Expr(Expr::Call(bracket_call(p))));
         }
 
+        // Code block.
         Token::LeftBrace => {
-            return Some(Node::Expr(block_expr(p)?));
+            return Some(Node::Expr(code_block(p)?));
         }
 
+        // Markup.
         Token::Star => Node::Strong,
         Token::Underscore => Node::Emph,
         Token::Tilde => Node::Text("\u{00A0}".into()),
-        Token::Backslash => Node::Linebreak,
         Token::Hash => {
             if at_start {
                 return Some(Node::Heading(heading(p)));
@@ -82,9 +70,24 @@ fn node(p: &mut Parser, at_start: bool) -> Option<Node> {
                 Node::Text(p.get(p.peek_span()).into())
             }
         }
+        Token::Backslash => Node::Linebreak,
+        Token::Space(newlines) => {
+            if newlines < 2 {
+                Node::Space
+            } else {
+                Node::Parbreak
+            }
+        }
+        Token::Text(text) => Node::Text(text.into()),
         Token::Raw(t) => Node::Raw(raw(p, t)),
         Token::UnicodeEscape(t) => Node::Text(unicode_escape(p, t)),
 
+        // Comments.
+        Token::LineComment(_) | Token::BlockComment(_) => {
+            p.eat();
+            return None;
+        }
+
         _ => {
             p.diag_unexpected();
             return None;
@@ -150,27 +153,6 @@ fn unicode_escape(p: &mut Parser, token: TokenUnicodeEscape) -> String {
     text
 }
 
-/// Parse a block expression.
-fn block_expr(p: &mut Parser) -> Option<Expr> {
-    p.push_mode(TokenMode::Code);
-    p.start_group(Group::Brace);
-    let expr = expr(p);
-    while !p.eof() {
-        p.diag_unexpected();
-    }
-    p.pop_mode();
-    p.end_group();
-    expr
-}
-
-/// Parse a parenthesized function call.
-fn paren_call(p: &mut Parser, name: Spanned<Ident>) -> ExprCall {
-    p.start_group(Group::Paren);
-    let args = p.span(arguments);
-    p.end_group();
-    ExprCall { name, args }
-}
-
 /// Parse a bracketed function call.
 fn bracket_call(p: &mut Parser) -> ExprCall {
     p.push_mode(TokenMode::Code);
@@ -189,7 +171,7 @@ fn bracket_call(p: &mut Parser) -> ExprCall {
     p.end_group();
 
     if p.peek() == Some(Token::LeftBracket) {
-        let body = p.span(|p| Expr::Content(bracket_body(p)));
+        let body = p.span(|p| Expr::Template(bracket_body(p)));
         inner.span.expand(body.span);
         inner.v.args.v.push(Argument::Pos(body));
     }
@@ -197,7 +179,7 @@ fn bracket_call(p: &mut Parser) -> ExprCall {
     while let Some(mut top) = outer.pop() {
         let span = inner.span;
         let node = inner.map(|c| Node::Expr(Expr::Call(c)));
-        let expr = Expr::Content(vec![node]).with_span(span);
+        let expr = Expr::Template(vec![node]).with_span(span);
         top.v.args.v.push(Argument::Pos(expr));
         inner = top;
     }
@@ -236,6 +218,19 @@ fn bracket_body(p: &mut Parser) -> Tree {
     tree
 }
 
+/// Parse a code block: `{...}`.
+fn code_block(p: &mut Parser) -> Option<Expr> {
+    p.push_mode(TokenMode::Code);
+    p.start_group(Group::Brace);
+    let expr = expr(p);
+    while !p.eof() {
+        p.diag_unexpected();
+    }
+    p.pop_mode();
+    p.end_group();
+    expr
+}
+
 /// Parse an expression: `term (+ term)*`.
 fn expr(p: &mut Parser) -> Option<Expr> {
     binops(p, term, |token| match token {
@@ -297,15 +292,14 @@ fn factor(p: &mut Parser) -> Option<Expr> {
 /// Parse a value.
 fn value(p: &mut Parser) -> Option<Expr> {
     let expr = match p.peek() {
-        // Bracketed function call.
+        // Template.
         Some(Token::LeftBracket) => {
-            let node = p.span(|p| Node::Expr(Expr::Call(bracket_call(p))));
-            return Some(Expr::Content(vec![node]));
+            return Some(Expr::Template(template(p)));
         }
 
-        // Content expression.
+        // Nested block.
         Some(Token::LeftBrace) => {
-            return Some(Expr::Content(content(p)));
+            return code_block(p);
         }
 
         // Dictionary or just a parenthesized expression.
@@ -346,16 +340,24 @@ fn value(p: &mut Parser) -> Option<Expr> {
     Some(expr)
 }
 
-// Parse a content value: `{...}`.
-fn content(p: &mut Parser) -> Tree {
+// Parse a template value: `[...]`.
+fn template(p: &mut Parser) -> Tree {
     p.push_mode(TokenMode::Markup);
-    p.start_group(Group::Brace);
+    p.start_group(Group::Bracket);
     let tree = tree(p);
     p.pop_mode();
     p.end_group();
     tree
 }
 
+/// Parse a parenthesized function call.
+fn paren_call(p: &mut Parser, name: Spanned<Ident>) -> ExprCall {
+    p.start_group(Group::Paren);
+    let args = p.span(arguments);
+    p.end_group();
+    ExprCall { name, args }
+}
+
 /// Parse an identifier.
 fn ident(p: &mut Parser) -> Option<Ident> {
     p.eat_map(|token| match token {
diff --git a/src/parse/tests.rs b/src/parse/tests.rs
index 3c57fa1f..a8897c1c 100644
--- a/src/parse/tests.rs
+++ b/src/parse/tests.rs
@@ -26,7 +26,7 @@ macro_rules! t {
         $(spans = $spans;)?
 
         let Pass { output, feedback } = parse($src);
-        check($src, Content![@$($node),*], output, spans);
+        check($src, Template![@$($node),*], output, spans);
         check(
             $src,
             vec![
@@ -158,9 +158,9 @@ macro_rules! Args {
     };
 }
 
-macro_rules! Content {
+macro_rules! Template {
     (@$($node:expr),* $(,)?) => (vec![$(into!($node)),*]);
-    ($($tts:tt)*) => (Expr::Content(Content![@$($tts)*]));
+    ($($tts:tt)*) => (Expr::Template(Template![@$($tts)*]));
 }
 
 macro_rules! Call {
@@ -227,30 +227,30 @@ fn test_parse_simple_nodes() {
 fn test_parse_headings() {
     // Basics with spans.
     t!("# a"
-        nodes: [S(0..3, Heading(S(0..1, 0), Content![
+        nodes: [S(0..3, Heading(S(0..1, 0), Template![
             @S(1..2, Space), S(2..3, Text("a"))
         ]))],
         spans: true);
 
     // Multiple hashtags.
-    t!("### three"   Heading(2, Content![@Space, Text("three")]));
-    t!("###### six" Heading(5, Content![@Space, Text("six")]));
+    t!("### three"   Heading(2, Template![@Space, Text("three")]));
+    t!("###### six" Heading(5, Template![@Space, Text("six")]));
 
     // Start of heading.
-    t!("/**/#"    Heading(0, Content![@]));
-    t!("[f][# ok]" Call!("f", Args![Content![Heading(0, Content![
+    t!("/**/#"    Heading(0, Template![@]));
+    t!("[f][# ok]" Call!("f", Args![Template![Heading(0, Template![
         @Space, Text("ok")
     ])]]));
 
     // End of heading.
-    t!("# a\nb" Heading(0, Content![@Space, Text("a")]), Space, Text("b"));
+    t!("# a\nb" Heading(0, Template![@Space, Text("a")]), Space, Text("b"));
 
     // Continued heading.
-    t!("# a{\n1\n}b"   Heading(0, Content![
+    t!("# a{\n1\n}b"   Heading(0, Template![
         @Space, Text("a"), Block(Int(1)), Text("b")
     ]));
-    t!("# a[f][\n\n]d" Heading(0, Content![@
-        Space, Text("a"), Call!("f", Args![Content![Parbreak]]), Text("d"),
+    t!("# a[f][\n\n]d" Heading(0, Template![@
+        Space, Text("a"), Call!("f", Args![Template![Parbreak]]), Text("d"),
     ]));
 
     // No heading.
@@ -260,7 +260,7 @@ fn test_parse_headings() {
 
     // Too many hashtags.
     t!("####### seven"
-        nodes: [Heading(5, Content![@Space, Text("seven")])],
+        nodes: [Heading(5, Template![@Space, Text("seven")])],
         warnings: [S(0..7, "section depth should not exceed 6")]);
 }
 
@@ -293,13 +293,9 @@ fn test_parse_escape_sequences() {
 #[test]
 fn test_parse_groups() {
     // Test paren group.
-    t!("{([v 1) + 3}"
-        nodes: [Block(Binary(
-            Content![Call!("v", Args![Int(1)])],
-            Add,
-            Int(3),
-        ))],
-        errors: [S(6..6, "expected closing bracket")]);
+    t!("{({1) + 3}"
+        nodes: [Block(Binary(Int(1), Add, Int(3)))],
+        errors: [S(4..4, "expected closing brace")]);
 
     // Test bracket group.
     t!("[)"
@@ -307,19 +303,18 @@ fn test_parse_groups() {
         errors: [S(1..2, "expected function name, found closing paren"),
                  S(2..2, "expected closing bracket")]);
 
-    t!("[v {*]_"
-        nodes: [Call!("v", Args![Content![Strong]]), Emph],
-        errors: [S(5..5, "expected closing brace")]);
+    t!("[v [*]"
+        nodes: [Call!("v", Args![Template![Strong]])],
+        errors: [S(6..6, "expected closing bracket")]);
 
     // Test brace group.
     t!("{1 + [}"
-        nodes: [Block(Binary(Int(1), Add, Content![Call!("")]))],
-        errors: [S(6..6, "expected function name"),
-                 S(6..6, "expected closing bracket")]);
+        nodes: [Block(Binary(Int(1), Add, Template![]))],
+        errors: [S(6..6, "expected closing bracket")]);
 
     // Test subheader group.
     t!("[v (|u )]"
-        nodes: [Call!("v", Args![Array![], Content![Call!("u")]])],
+        nodes: [Call!("v", Args![Array![], Template![Call!("u")]])],
         errors: [S(4..4, "expected closing paren"),
                  S(7..8, "expected expression, found closing paren")]);
 }
@@ -331,7 +326,7 @@ fn test_parse_blocks() {
 
     // Function calls.
     t!("{f()}" Call!("f"));
-    t!("{[f]}" Block(Content![Call!("f")]));
+    t!("{[[f]]}" Block(Template![Call!("f")]));
 
     // Missing or bad value.
     t!("{}{1u}"
@@ -353,15 +348,15 @@ fn test_parse_bracket_funcs() {
     t!("[ v ]"      Call!("v"));
 
     // Body and no body.
-    t!("[v][[f]]"  Call!("v", Args![Content![Call!("f")]]));
-    t!("[v][v][v]" Call!("v", Args![Content![Text("v")]]), Call!("v"));
+    t!("[v][[f]]"  Call!("v", Args![Template![Call!("f")]]));
+    t!("[v][v][v]" Call!("v", Args![Template![Text("v")]]), Call!("v"));
     t!("[v] [f]"   Call!("v"), Space, Call!("f"));
 
     // Spans.
     t!("[v 1][📐]"
         nodes: [S(0..11, Call!(S(1..2, "v"), S(3..4, Args![
             S(3..4, Int(1)),
-            S(5..11, Content![S(6..10, Text("📐"))]),
+            S(5..11, Template![S(6..10, Text("📐"))]),
         ])))],
         spans: true);
 
@@ -389,35 +384,35 @@ fn test_parse_bracket_funcs() {
 
     // Raw in body eats closing bracket.
     t!("[v][`a]`"
-        nodes: [Call!("v", Args![Content![Raw(None, &["a]"], true)]])],
+        nodes: [Call!("v", Args![Template![Raw(None, &["a]"], true)]])],
         errors: [S(8..8, "expected closing bracket")]);
 }
 
 #[test]
 fn test_parse_chaining() {
     // Basic.
-    t!("[a | b]" Call!("a", Args![Content![Call!("b")]]));
-    t!("[a|b|c]" Call!("a", Args![Content![
-        Call!("b", Args![Content![Call!("c")]])
+    t!("[a | b]" Call!("a", Args![Template![Call!("b")]]));
+    t!("[a|b|c]" Call!("a", Args![Template![
+        Call!("b", Args![Template![Call!("c")]])
     ]]));
 
     // With body and spans.
     t!("[a|b][💕]"
         nodes: [S(0..11, Call!(S(1..2, "a"), S(2..2, Args![
-            S(3..11, Content![S(3..11, Call!(S(3..4, "b"), S(4..4, Args![
-                S(5..11, Content![S(6..10, Text("💕"))])
+            S(3..11, Template![S(3..11, Call!(S(3..4, "b"), S(4..4, Args![
+                S(5..11, Template![S(6..10, Text("💕"))])
             ])))])
         ])))],
         spans: true);
 
     // No name in second subheader.
     t!("[a 1|]"
-        nodes: [Call!("a", Args![Int(1), Content![Call!("")]])],
+        nodes: [Call!("a", Args![Int(1), Template![Call!("")]])],
         errors: [S(5..5, "expected function name")]);
 
     // No name in first subheader.
     t!("[|a true]"
-        nodes: [Call!("", Args![Content![Call!("a", Args![Bool(true)])]])],
+        nodes: [Call!("", Args![Template![Call!("a", Args![Bool(true)])]])],
         errors: [S(1..1, "expected function name")]);
 }
 
@@ -534,12 +529,12 @@ fn test_parse_dictionaries() {
         errors: [S(8..9, "expected named pair, found expression")]);
 
     // Dictionary marker followed by more stuff.
-    t!("{(:1 b:2, true::)}"
-        nodes: [Block(Dict!["b" => Int(2)])],
+    t!("{(:1 b:[], true::)}"
+        nodes: [Block(Dict!["b" => Template![]])],
         errors: [S(3..4, "expected named pair, found expression"),
                  S(4..4, "expected comma"),
-                 S(10..14, "name must be identifier"),
-                 S(15..16, "expected expression, found colon")]);
+                 S(11..15, "name must be identifier"),
+                 S(16..17, "expected expression, found colon")]);
 }
 
 #[test]
@@ -615,7 +610,11 @@ fn test_parse_values() {
         errors: [S(1..4, "invalid color")]);
 
     // Content.
-    t!("{{*Hi*}}" Block(Content![Strong, Text("Hi"), Strong]));
+    t!("{[*Hi*]}" Block(Template![Strong, Text("Hi"), Strong]));
+
+    // Nested blocks.
+    t!("{{1}}" Block(Int(1)));
+    t!("{{{1+2}}}" Block(Binary(Int(1), Add, Int(2))));
 
     // Invalid tokens.
     t!("{1u}"
diff --git a/src/parse/tokens.rs b/src/parse/tokens.rs
index 28ca6e48..d16cf2ce 100644
--- a/src/parse/tokens.rs
+++ b/src/parse/tokens.rs
@@ -562,7 +562,7 @@ mod tests {
     }
 
     #[test]
-    fn test_tokenize_body_symbols() {
+    fn test_tokenize_markup_symbols() {
         // Test markup tokens.
         t!(Markup[" a1"]: "*"  => Star);
         t!(Markup: "_"         => Underscore);
@@ -572,7 +572,7 @@ mod tests {
     }
 
     #[test]
-    fn test_tokenize_header_symbols() {
+    fn test_tokenize_code_symbols() {
         // Test all symbols.
         t!(Code: ","        => Comma);
         t!(Code: ":"        => Colon);
@@ -654,6 +654,27 @@ mod tests {
     }
 
     #[test]
+    fn test_tokenize_whitespace() {
+        // Test basic whitespace.
+        t!(Both["a1/"]: ""         => );
+        t!(Both["a1/"]: " "        => Space(0));
+        t!(Both["a1/"]: "    "     => Space(0));
+        t!(Both["a1/"]: "\t"       => Space(0));
+        t!(Both["a1/"]: "  \t"     => Space(0));
+        t!(Both["a1/"]: "\u{202F}" => Space(0));
+
+        // Test newline counting.
+        t!(Both["a1/"]: "\n"           => Space(1));
+        t!(Both["a1/"]: "\n "          => Space(1));
+        t!(Both["a1/"]: "  \n"         => Space(1));
+        t!(Both["a1/"]: "  \n   "      => Space(1));
+        t!(Both["a1/"]: "\r\n"         => Space(1));
+        t!(Both["a1/"]: "  \n\t \n  "  => Space(2));
+        t!(Both["a1/"]: "\n\r"         => Space(2));
+        t!(Both["a1/"]: " \r\r\n \x0D" => Space(3));
+    }
+
+    #[test]
     fn test_tokenize_text() {
         // Test basic text.
         t!(Markup[" /"]: "hello"       => Text("hello"));
@@ -739,27 +760,6 @@ mod tests {
     }
 
     #[test]
-    fn test_tokenize_whitespace() {
-        // Test basic whitespace.
-        t!(Both["a1/"]: ""         => );
-        t!(Both["a1/"]: " "        => Space(0));
-        t!(Both["a1/"]: "    "     => Space(0));
-        t!(Both["a1/"]: "\t"       => Space(0));
-        t!(Both["a1/"]: "  \t"     => Space(0));
-        t!(Both["a1/"]: "\u{202F}" => Space(0));
-
-        // Test newline counting.
-        t!(Both["a1/"]: "\n"           => Space(1));
-        t!(Both["a1/"]: "\n "          => Space(1));
-        t!(Both["a1/"]: "  \n"         => Space(1));
-        t!(Both["a1/"]: "  \n   "      => Space(1));
-        t!(Both["a1/"]: "\r\n"         => Space(1));
-        t!(Both["a1/"]: "  \n\t \n  "  => Space(2));
-        t!(Both["a1/"]: "\n\r"         => Space(2));
-        t!(Both["a1/"]: " \r\r\n \x0D" => Space(3));
-    }
-
-    #[test]
     fn test_tokenize_idents() {
         // Test valid identifiers.
         t!(Code[" /"]: "x"           => Ident("x"));
diff --git a/src/prelude.rs b/src/prelude.rs
index 1db0d5b0..9856a837 100644
--- a/src/prelude.rs
+++ b/src/prelude.rs
@@ -3,8 +3,8 @@
 pub use crate::diag::{Feedback, Pass};
 #[doc(no_inline)]
 pub use crate::eval::{
-    Args, CastResult, Eval, EvalContext, Value, ValueAny, ValueArray, ValueContent,
-    ValueDict,
+    Args, CastResult, Eval, EvalContext, Value, ValueAny, ValueArray, ValueDict,
+    ValueTemplate,
 };
 pub use crate::geom::*;
 #[doc(no_inline)]
diff --git a/src/syntax/expr.rs b/src/syntax/expr.rs
index 834c4393..cb09041c 100644
--- a/src/syntax/expr.rs
+++ b/src/syntax/expr.rs
@@ -38,8 +38,8 @@ pub enum Expr {
     Array(ExprArray),
     /// A dictionary expression: `(color: #f79143, pattern: dashed)`.
     Dict(ExprDict),
-    /// A content expression: `{*Hello* there!}`.
-    Content(ExprContent),
+    /// A template expression: `[*Hi* there!]`.
+    Template(ExprTemplate),
 }
 
 impl Pretty for Expr {
@@ -60,24 +60,16 @@ impl Pretty for Expr {
             Self::Binary(binary) => binary.pretty(p),
             Self::Array(array) => array.pretty(p),
             Self::Dict(dict) => dict.pretty(p),
-            Self::Content(content) => pretty_content_expr(content, p),
+            Self::Template(template) => pretty_template_expr(template, p),
         }
     }
 }
 
-/// Pretty print content in an expression context.
-pub fn pretty_content_expr(tree: &Tree, p: &mut Printer) {
-    if let [Spanned { v: Node::Expr(Expr::Call(call)), .. }] = tree.as_slice() {
-        // Remove unncessary braces from content expression containing just a
-        // single function call.
-        //
-        // Example: Transforms "{(call: {[f]})}" => "{(call: [f])}"
-        pretty_bracket_call(call, p, false);
-    } else {
-        p.push_str("{");
-        tree.pretty(p);
-        p.push_str("}");
-    }
+/// Pretty print a template in an expression context.
+pub fn pretty_template_expr(tree: &Tree, p: &mut Printer) {
+    p.push_str("[");
+    tree.pretty(p);
+    p.push_str("]");
 }
 
 /// An invocation of a function: `[foo ...]`, `foo(...)`.
@@ -111,8 +103,8 @@ pub fn pretty_bracket_call(call: &ExprCall, p: &mut Printer, chained: bool) {
 
     // Find out whether this can be written with a body or as a chain.
     //
-    // Example: Transforms "[v {Hi}]" => "[v][Hi]".
-    if let [head @ .., Argument::Pos(Spanned { v: Expr::Content(content), .. })] =
+    // Example: Transforms "[v [Hi]]" => "[v][Hi]".
+    if let [head @ .., Argument::Pos(Spanned { v: Expr::Template(template), .. })] =
         call.args.v.as_slice()
     {
         // Previous arguments.
@@ -124,11 +116,11 @@ pub fn pretty_bracket_call(call: &ExprCall, p: &mut Printer, chained: bool) {
         // Find out whether this can written as a chain.
         //
         // Example: Transforms "[v][[f]]" => "[v | f]".
-        if let [Spanned { v: Node::Expr(Expr::Call(call)), .. }] = content.as_slice() {
+        if let [Spanned { v: Node::Expr(Expr::Call(call)), .. }] = template.as_slice() {
             return pretty_bracket_call(call, p, true);
         } else {
             p.push_str("][");
-            content.pretty(p);
+            template.pretty(p);
         }
     } else if !call.args.v.is_empty() {
         p.push_str(" ");
@@ -291,8 +283,8 @@ impl Pretty for ExprDict {
     }
 }
 
-/// A content expression: `{*Hello* there!}`.
-pub type ExprContent = Tree;
+/// A template expression: `[*Hi* there!]`.
+pub type ExprTemplate = Tree;
 
 #[cfg(test)]
 mod tests {
@@ -301,8 +293,7 @@ mod tests {
     #[test]
     fn test_pretty_print_chaining() {
         // All equivalent.
-        test_pretty("[v [f]]", "[v | f]");
-        test_pretty("[v {[f]}]", "[v | f]");
+        test_pretty("[v [[f]]]", "[v | f]");
         test_pretty("[v][[f]]", "[v | f]");
         test_pretty("[v | f]", "[v | f]");
     }
@@ -321,9 +312,8 @@ mod tests {
         test_pretty("{(:)}", "{(:)}");
         test_pretty("{(percent: 5%)}", "{(percent: 5%)}");
 
-        // Content expression without unncessary braces.
-        test_pretty("[v [f], 1]", "[v [f], 1]");
-        test_pretty("(func: {[f]})", "(func: [f])");
+        // Content expression.
+        test_pretty("[v [[f]], 1]", "[v [[f]], 1]");
     }
 
     #[test]
diff --git a/src/syntax/node.rs b/src/syntax/node.rs
index 01b4ee42..e7091a40 100644
--- a/src/syntax/node.rs
+++ b/src/syntax/node.rs
@@ -3,18 +3,18 @@ use super::*;
 /// A syntax node, encompassing a single logical entity of parsed source code.
 #[derive(Debug, Clone, PartialEq)]
 pub enum Node {
-    /// Plain text.
-    Text(String),
+    /// Strong text was enabled / disabled.
+    Strong,
+    /// Emphasized text was enabled / disabled.
+    Emph,
     /// Whitespace containing less than two newlines.
     Space,
     /// A forced line break.
     Linebreak,
     /// A paragraph break.
     Parbreak,
-    /// Strong text was enabled / disabled.
-    Strong,
-    /// Emphasized text was enabled / disabled.
-    Emph,
+    /// Plain text.
+    Text(String),
     /// A section heading.
     Heading(NodeHeading),
     /// An optionally syntax-highlighted raw block.
@@ -26,12 +26,12 @@ pub enum Node {
 impl Pretty for Node {
     fn pretty(&self, p: &mut Printer) {
         match self {
-            Self::Text(text) => p.push_str(&text),
+            Self::Strong => p.push_str("*"),
+            Self::Emph => p.push_str("_"),
             Self::Space => p.push_str(" "),
             Self::Linebreak => p.push_str(r"\"),
             Self::Parbreak => p.push_str("\n\n"),
-            Self::Strong => p.push_str("*"),
-            Self::Emph => p.push_str("_"),
+            Self::Text(text) => p.push_str(&text),
             Self::Heading(heading) => heading.pretty(p),
             Self::Raw(raw) => raw.pretty(p),
             Self::Expr(expr) => pretty_expr_node(expr, p),
@@ -50,8 +50,8 @@ pub fn pretty_expr_node(expr: &Expr, p: &mut Printer) {
 
         // Remove unncessary nesting of content and expression blocks.
         //
-        // Example: Transforms "{{Hi}}" => "Hi".
-        Expr::Content(content) => content.pretty(p),
+        // Example: Transforms "{[Hi]}" => "Hi".
+        Expr::Template(template) => template.pretty(p),
 
         _ => {
             p.push_str("{");
@@ -179,9 +179,9 @@ mod tests {
 
     #[test]
     fn test_pretty_print_removes_nesting() {
-        // Even levels of nesting do not matter.
-        test_pretty("{{Hi}}", "Hi");
-        test_pretty("{{{{Hi}}}}", "Hi");
+        // Nesting does not matter.
+        test_pretty("{{x}}", "{x}");
+        test_pretty("{{{x}}}", "{x}");
     }
 
     #[test]
@@ -189,8 +189,7 @@ mod tests {
         // All reduces to a simple bracket call.
         test_pretty("{v()}", "[v]");
         test_pretty("[v]", "[v]");
-        test_pretty("{[v]}", "[v]");
-        test_pretty("{{[v]}}", "[v]");
+        test_pretty("{[[v]]}", "[v]");
     }
 
     #[test]