Always parse bodies as syntax trees 🌳

Previously they were passed as strings to the function parser, now they are parsed and then passed as trees to the function. This allows making bodies sugar for a last content argument. While it removes some flexibility allowing function to parse arbitrary syntaxes in their bodies, these can be modelled as (raw) string arguments.

src/func.rs

@@ -56,21 +56,8 @@ pub fn drain_args(args: FuncArgs, f: &mut Feedback) {
     }
 }
 
-/// Parse a function's body if there is one or return `None` otherwise.
-pub fn parse_body_maybe(
-    body: Option<Spanned<&str>>,
-    state: &ParseState,
-    f: &mut Feedback,
-) -> Option<SyntaxTree> {
-    body.map(|body| {
-        let parsed = parse(body.v, body.span.start, state);
-        f.extend(parsed.feedback);
-        parsed.output
-    })
-}
-
 /// Generate an error if there is function body even though none was expected.
-pub fn expect_no_body(body: Option<Spanned<&str>>, f: &mut Feedback) {
+pub fn expect_no_body(body: FuncBody, f: &mut Feedback) {
     if let Some(body) = body {
         error!(@f, body.span, "unexpected body");
     }

src/library/align.rs

@@ -10,11 +10,11 @@ use super::*;
 /// - `vertical`: Any of `top`, `bottom` or `center`.
 ///
 /// There may not be two alignment specifications for the same axis.
-pub fn align(call: FuncCall, state: &ParseState) -> Pass<SyntaxNode> {
+pub fn align(call: FuncCall, _: &ParseState) -> Pass<SyntaxNode> {
     let mut f = Feedback::new();
     let mut args = call.header.args;
     let node = AlignNode {
-        body: parse_body_maybe(call.body, state, &mut f),
+        body: call.body.map(|s| s.v),
         aligns: args.pos.all::<Spanned<SpecAlign>>().collect(),
         h: args.key.get::<Spanned<SpecAlign>>("horizontal", &mut f),
         v: args.key.get::<Spanned<SpecAlign>>("vertical", &mut f),

src/library/boxed.rs

@@ -6,11 +6,11 @@ use super::*;
 /// # Keyword arguments
 /// - `width`: The width of the box (length of relative to parent's width).
 /// - `height`: The height of the box (length of relative to parent's height).
-pub fn boxed(call: FuncCall, state: &ParseState) -> Pass<SyntaxNode> {
+pub fn boxed(call: FuncCall, _: &ParseState) -> Pass<SyntaxNode> {
     let mut f = Feedback::new();
     let mut args = call.header.args;
     let node = BoxNode {
-        body: parse_body_maybe(call.body, state, &mut f).unwrap_or(SyntaxTree::new()),
+        body: call.body.map(|s| s.v).unwrap_or(SyntaxTree::new()),
         width: args.key.get::<ScaleLength>("width", &mut f),
         height: args.key.get::<ScaleLength>("height", &mut f),
     };

src/library/font.rs

@@ -18,12 +18,12 @@ use super::*;
 ///   ```typst
 ///   serif = ("Source Serif Pro", "Noto Serif")
 ///   ```
-pub fn font(call: FuncCall, state: &ParseState) -> Pass<SyntaxNode> {
+pub fn font(call: FuncCall, _: &ParseState) -> Pass<SyntaxNode> {
     let mut f = Feedback::new();
     let mut args = call.header.args;
 
     let node = FontNode {
-        body: parse_body_maybe(call.body, state, &mut f),
+        body: call.body.map(|s| s.v),
         size: args.pos.get::<ScaleLength>(),
         style: args.key.get::<FontStyle>("style", &mut f),
         weight: args.key.get::<FontWeight>("weight", &mut f),

src/library/val.rs

@@ -4,12 +4,11 @@ use super::*;
 ///
 /// This is also the fallback function, which is used when a function name
 /// cannot be resolved.
-pub fn val(call: FuncCall, state: &ParseState) -> Pass<SyntaxNode> {
+pub fn val(call: FuncCall, _: &ParseState) -> Pass<SyntaxNode> {
-    let mut f = Feedback::new();
     let node = ValNode {
-        body: parse_body_maybe(call.body, state, &mut f),
+        body: call.body.map(|s| s.v),
     };
-    Pass::node(node, f)
+    Pass::node(node, Feedback::new())
 }
 
 #[derive(Debug, Clone, PartialEq)]

src/syntax/parsing.rs

@@ -15,9 +15,9 @@ pub type CallParser = dyn Fn(FuncCall, &ParseState) -> Pass<SyntaxNode>;
 
 /// An invocation of a function.
 #[derive(Debug, Clone, PartialEq)]
-pub struct FuncCall<'s> {
+pub struct FuncCall {
     pub header: FuncHeader,
-    pub body: FuncBody<'s>,
+    pub body: FuncBody,
 }
 
 /// The parsed header of a function (everything in the first set of brackets).
@@ -29,7 +29,7 @@ pub struct FuncHeader {
 
 /// The body of a function as a raw spanned string containing what's inside of
 /// the brackets.
-pub type FuncBody<'s> = Option<Spanned<&'s str>>;
+pub type FuncBody = Option<Spanned<SyntaxTree>>;
 
 /// The positional and keyword arguments passed to a function.
 #[derive(Debug, Default, Clone, PartialEq)]
@@ -196,9 +196,17 @@ impl<'s> FuncParser<'s> {
             (parser, header)
         };
 
-        let call = FuncCall { header, body: self.body };
+        let body = self.body.map(|body| body.map(|src| {
+            let parsed = parse(src, body.span.start, &self.state);
+            self.feedback.extend(parsed.feedback);
+            parsed.output
+        }));
+
+        let call = FuncCall { header, body };
+
         let parsed = parser(call, self.state);
         self.feedback.extend(parsed.feedback);
+
         Pass::new(parsed.output, self.feedback)
     }
 

src/syntax/test.rs

@@ -58,13 +58,12 @@ macro_rules! span_item {
     };
 }
 
-pub fn debug_func(call: FuncCall, state: &ParseState) -> Pass<SyntaxNode> {
+pub fn debug_func(call: FuncCall, _: &ParseState) -> Pass<SyntaxNode> {
-    let mut f = Feedback::new();
     let node = DebugNode {
         header: call.header,
-        body: parse_body_maybe(call.body, state, &mut f),
+        body: call.body.map(|s| s.v),
     };
-    Pass::node(node, f)
+    Pass::node(node, Feedback::new())
 }
 
 #[derive(Debug, Clone, PartialEq)]