Support for wrap

src/eval/mod.rs

@@ -178,16 +178,31 @@ impl Eval for Markup {
     type Output = Node;
 
     fn eval(&self, ctx: &mut EvalContext) -> TypResult<Self::Output> {
+        process_nodes(ctx, &mut self.nodes())
+    }
+}
+
+/// Evaluate a stream of nodes.
+fn process_nodes(
+    ctx: &mut EvalContext,
+    nodes: &mut impl Iterator<Item = MarkupNode>,
+) -> TypResult<Node> {
     let prev = mem::take(&mut ctx.styles);
-        let nodes = self.nodes();
+    let mut seq = Vec::with_capacity(nodes.size_hint().1.unwrap_or_default());
-        let upper = nodes.size_hint().1.unwrap_or_default();
+    while let Some(piece) = nodes.next() {
-        let mut seq = Vec::with_capacity(upper);
+        // Need to deal with wrap here.
-        for piece in nodes {
+        let node = if let MarkupNode::Expr(Expr::Wrap(wrap)) = piece {
-            seq.push(Styled::new(piece.eval(ctx)?, ctx.styles.clone()));
+            let tail = process_nodes(ctx, nodes)?;
+            ctx.scopes.def_mut(wrap.binding().take(), tail);
+            wrap.body().eval(ctx)?.show()
+        } else {
+            piece.eval(ctx)?
+        };
+
+        seq.push(Styled::new(node, ctx.styles.clone()));
     }
     ctx.styles = prev;
     Ok(Node::Sequence(seq))
-    }
 }
 
 impl Eval for MarkupNode {
@@ -265,8 +280,8 @@ impl RawNode {
                         sequence.push(Styled::bare(Node::Linebreak));
                     }
 
-                    for (style, line) in highlighter.highlight(line, &SYNTAXES) {
+                    for (style, piece) in highlighter.highlight(line, &SYNTAXES) {
-                        sequence.push(Self::styled_piece(style, line, foreground));
+                        sequence.push(style_piece(piece, foreground, style));
                     }
                 }
             }
@@ -279,11 +294,7 @@ impl RawNode {
                     red.as_ref(),
                     &highlighter,
                     &mut |range, style| {
-                        sequence.push(Self::styled_piece(
+                        sequence.push(style_piece(&self.text[range], foreground, style));
-                            style,
-                            &self.text[range],
-                            foreground,
-                        ));
                     },
                 )
             }
@@ -291,8 +302,10 @@ impl RawNode {
 
         Node::Sequence(sequence).monospaced()
     }
+}
 
-    fn styled_piece(style: SynStyle, piece: &str, foreground: Paint) -> Styled<Node> {
+/// Style a piece of text with a syntect style.
+fn style_piece(piece: &str, foreground: Paint, style: SynStyle) -> Styled<Node> {
     let paint = style.foreground.into();
     let node = Node::Text(piece.into());
 
@@ -315,7 +328,6 @@ impl RawNode {
     }
 
     Styled::new(node, styles)
-    }
 }
 
 impl Eval for MathNode {
@@ -776,7 +788,7 @@ impl Eval for WrapExpr {
     type Output = Value;
 
     fn eval(&self, _: &mut EvalContext) -> TypResult<Self::Output> {
-        Err("wrap is not yet implemented").at(self.span())
+        Err("wrap is only allowed directly in markup").at(self.span())
     }
 }
 

tests/typ/style/wrap.typ

@@ -1,6 +1,23 @@
 // Test wrap.
-// Ref: false
 
 ---
-// Error: 1-31 wrap is not yet implemented
+#set page(height: 130pt)
+#set text(70%)
+
+#align(center)[
+  #text(130%)[*Essay on typography*] \
+  T. Ypst
+]
+
 #wrap body in columns(2, body)
+Great typography is at the essence of great storytelling. It is the medium that
+transports meaning from parchment to reader, the wave that sparks a flame
+in booklovers and the great fulfiller of human need.
+
+---
+// Test wrap in template.
+A [_B #wrap c in [*#c*]; C] D
+
+---
+// Error: 6-17 wrap is only allowed directly in markup
+{1 + wrap x in y}