added notes

src/diagram.typ

@@ -57,7 +57,8 @@
 
   // List participants
   let linked = ()
-  for elmt in elmts {
+  let last-seq = none
+  for (i, elmt) in elmts.enumerate() {
     if elmt.type == "par" {
       participants.push(elmt)
     } else if elmt.type == "seq" {
@@ -73,15 +74,44 @@
         participants.at(i).from-start = false
       }
 
+      let p1 = elmt.p1
+      let p2 = elmt.p2
       if elmt.p1 == "?" {
-        linked.push("?" + elmt.p2)
-      } else {
-        linked.push(elmt.p1)
+        p1 = "?" + elmt.p2
       }
       if elmt.p2 == "?" {
-        linked.push(elmt.p1 + "?")
-      } else {
-        linked.push(elmt.p2)
+        p2 = elmt.p1 + "?"
+      }
+      linked.push(p1)
+      linked.push(p2)
+      last-seq = (
+        elmt: elmt,
+        i: i,
+        p1: p1,
+        p2: p2
+      )
+    } else if elmt.type == "note" {
+      elmt.insert("linked", elmt.pos == none and elmt.side != "across")
+      if elmt.pos == none and elmt.side != "across" {
+        let names = participants.map(p => p.name)
+        let i1 = names.position(n => n == last-seq.p1)
+        let i2 = names.position(n => n == last-seq.p2)
+        let pars = ((i1, last-seq.p1), (i2, last-seq.p2)).sorted(key: p => p.first())
+        if elmt.side == "left" {
+          elmt.pos = pars.first().last()
+        } else if elmt.side == "right" {
+          elmt.pos = pars.last().last()
+        }
+
+        let seq = last-seq.elmt
+        seq.insert("linked-note", elmt)
+        elmts.at(last-seq.i) = seq
+      }
+      elmts.at(i) = elmt
+      if elmt.side == "left" {
+        linked.push("[")
+      } else if elmt.side == "right" {
+        linked.push("]")
       }
     }
   }
@@ -137,6 +167,7 @@
     }
   }
 
+  set text(font: "Source Sans 3")
   render(participants, elmts)
 }