Locatable groups

7 files changed, 29 insertions, 16 deletions

diff --git a/src/library/layout/grid.rs b/src/library/layout/grid.rs
index 5b621732..4cad9de6 100644
--- a/src/library/layout/grid.rs
+++ b/src/library/layout/grid.rs
@@ -204,7 +204,9 @@ impl<'a> GridLayouter<'a> {
 
     /// Determines the columns sizes and then layouts the grid row-by-row.
     pub fn layout(mut self) -> TypResult<Vec<Arc<Frame>>> {
+        self.ctx.pins.freeze();
         self.measure_columns()?;
+        self.ctx.pins.unfreeze();
 
         for y in 0 .. self.rows.len() {
             // Skip to next region if current one is full, but only for content
@@ -370,10 +372,12 @@ impl<'a> GridLayouter<'a> {
                     pod.base.x = self.regions.base.x;
                 }
 
+                self.ctx.pins.freeze();
                 let mut sizes = node
                     .layout(self.ctx, &pod, self.styles)?
                     .into_iter()
                     .map(|frame| frame.size.y);
+                self.ctx.pins.unfreeze();
 
                 // For each region, we want to know the maximum height any
                 // column requires.
diff --git a/src/library/utility/locate.rs b/src/library/layout/locate.rs
index 0352199f..e94a48ba 100644
--- a/src/library/utility/locate.rs
+++ b/src/library/layout/locate.rs
@@ -1,8 +1,14 @@
 use crate::library::prelude::*;
-use crate::model::LocateNode;
+use crate::model::{Group, LocateNode};
 
 /// Format content with access to its location on the page.
 pub fn locate(_: &mut Machine, args: &mut Args) -> TypResult<Value> {
     let node = LocateNode::new(args.expect("recipe")?);
     Ok(Value::Content(Content::Locate(node)))
 }
+
+/// Create a new group of locatable elements.
+pub fn group(_: &mut Machine, args: &mut Args) -> TypResult<Value> {
+    let key = args.expect("key")?;
+    Ok(Value::dynamic(Group::new(key)))
+}
diff --git a/src/library/layout/mod.rs b/src/library/layout/mod.rs
index 588b15aa..6cf5b550 100644
--- a/src/library/layout/mod.rs
+++ b/src/library/layout/mod.rs
@@ -5,6 +5,7 @@ mod columns;
 mod container;
 mod flow;
 mod grid;
+mod locate;
 mod pad;
 mod page;
 mod place;
@@ -16,6 +17,7 @@ pub use columns::*;
 pub use container::*;
 pub use flow::*;
 pub use grid::*;
+pub use locate::*;
 pub use pad::*;
 pub use page::*;
 pub use place::*;
diff --git a/src/library/mod.rs b/src/library/mod.rs
index 3321a36b..cf5d6e64 100644
--- a/src/library/mod.rs
+++ b/src/library/mod.rs
@@ -54,6 +54,8 @@ pub fn new() -> Scope {
     std.def_node::<layout::ColumnsNode>("columns");
     std.def_node::<layout::ColbreakNode>("colbreak");
     std.def_node::<layout::PlaceNode>("place");
+    std.def_fn("locate", layout::locate);
+    std.def_fn("group", layout::group);
 
     // Graphics.
     std.def_node::<graphics::ImageNode>("image");
@@ -92,7 +94,6 @@ pub fn new() -> Scope {
     std.def_fn("roman", utility::roman);
     std.def_fn("symbol", utility::symbol);
     std.def_fn("lorem", utility::lorem);
-    std.def_fn("locate", utility::locate);
 
     // Predefined colors.
     std.def_const("black", Color::BLACK);
diff --git a/src/library/prelude.rs b/src/library/prelude.rs
index 371d6776..a61157a7 100644
--- a/src/library/prelude.rs
+++ b/src/library/prelude.rs
@@ -9,8 +9,8 @@ pub use typst_macros::node;
 
 pub use crate::diag::{with_alternative, At, Error, StrResult, TypError, TypResult};
 pub use crate::eval::{
-    Arg, Args, Array, Cast, Dict, Func, Machine, Node, RawAlign, RawLength, RawStroke,
-    Scope, Smart, Value,
+    Arg, Args, Array, Cast, Dict, Dynamic, Func, Machine, Node, RawAlign, RawLength,
+    RawStroke, Scope, Smart, Value,
 };
 pub use crate::frame::*;
 pub use crate::geom::*;
diff --git a/src/library/text/par.rs b/src/library/text/par.rs
index 65098b61..709dc756 100644
--- a/src/library/text/par.rs
+++ b/src/library/text/par.rs
@@ -194,10 +194,11 @@ impl LinebreakNode {
 /// Range of a substring of text.
 type Range = std::ops::Range<usize>;
 
-// The characters by which spacing and nodes are replaced in the paragraph's
-// full text.
-const SPACING_REPLACE: char = ' ';
-const NODE_REPLACE: char = '\u{FFFC}';
+// The characters by which spacing, nodes and pins are replaced in the
+// paragraph's full text.
+const SPACING_REPLACE: char = ' '; // Space
+const NODE_REPLACE: char = '\u{FFFC}'; // Object Replacement Character
+const PIN_REPLACE: char = '\u{200D}'; // Zero Width Joiner
 
 /// A paragraph representation in which children are already layouted and text
 /// is already preshaped.
@@ -287,8 +288,9 @@ impl Segment<'_> {
     fn len(&self) -> usize {
         match *self {
             Self::Text(len) => len,
-            Self::Spacing(_) | Self::Pin(_) => SPACING_REPLACE.len_utf8(),
+            Self::Spacing(_) => SPACING_REPLACE.len_utf8(),
             Self::Node(_) => NODE_REPLACE.len_utf8(),
+            Self::Pin(_) => PIN_REPLACE.len_utf8(),
         }
     }
 }
@@ -323,10 +325,9 @@ impl<'a> Item<'a> {
     fn len(&self) -> usize {
         match self {
             Self::Text(shaped) => shaped.text.len(),
-            Self::Absolute(_) | Self::Fractional(_) | Self::Pin(_) => {
-                SPACING_REPLACE.len_utf8()
-            }
+            Self::Absolute(_) | Self::Fractional(_) => SPACING_REPLACE.len_utf8(),
             Self::Frame(_) | Self::Repeat(_, _) => NODE_REPLACE.len_utf8(),
+            Self::Pin(_) => PIN_REPLACE.len_utf8(),
         }
     }
 
@@ -465,8 +466,9 @@ fn collect<'a>(
                     let peeked = iter.peek().and_then(|(child, _)| match child {
                         ParChild::Text(text) => text.chars().next(),
                         ParChild::Quote { .. } => Some('"'),
-                        ParChild::Spacing(_) | ParChild::Pin(_) => Some(SPACING_REPLACE),
+                        ParChild::Spacing(_) => Some(SPACING_REPLACE),
                         ParChild::Node(_) => Some(NODE_REPLACE),
+                        ParChild::Pin(_) => Some(PIN_REPLACE),
                     });
 
                     full.push_str(quoter.quote(&quotes, double, peeked));
@@ -484,7 +486,7 @@ fn collect<'a>(
                 Segment::Node(node)
             }
             &ParChild::Pin(idx) => {
-                full.push(SPACING_REPLACE);
+                full.push(PIN_REPLACE);
                 Segment::Pin(idx)
             }
         };
diff --git a/src/library/utility/mod.rs b/src/library/utility/mod.rs
index 32815607..10aa7c7a 100644
--- a/src/library/utility/mod.rs
+++ b/src/library/utility/mod.rs
@@ -1,12 +1,10 @@
 //! Computational utility functions.
 
 mod color;
-mod locate;
 mod math;
 mod string;
 
 pub use color::*;
-pub use locate::*;
 pub use math::*;
 pub use string::*;