better appendix internal links

d2renderers/d2svg/appendix/appendix.go

@@ -11,6 +11,7 @@ import (
 	"strings"
 
 	"oss.terrastruct.com/d2/d2graph"
+	"oss.terrastruct.com/d2/d2parser"
 	"oss.terrastruct.com/d2/d2renderers/d2fonts"
 	"oss.terrastruct.com/d2/d2renderers/d2svg"
 	"oss.terrastruct.com/d2/d2target"
@@ -162,6 +163,33 @@ func Append(diagram *d2target.Diagram, ruler *textmeasure.Ruler, in []byte) []by
 	return []byte(svg)
 }
 
+// transformInternalLink turns
+// "root.layers.x.layers.y"
+// into
+// "[name] > x > y"
+func transformInternalLink(rootName, link string) string {
+	if link == "" || !strings.HasPrefix(link, "root") {
+		return link
+	}
+
+	mk, err := d2parser.ParseMapKey(link)
+	if err != nil {
+		return ""
+	}
+
+	key := d2graph.Key(mk.Key)
+
+	key[0] = rootName
+
+	if len(key) > 1 {
+		for i := 1; i < len(key); i += 2 {
+			key[i] = ">"
+		}
+	}
+
+	return strings.Join(key, " ")
+}
+
 func generateAppendix(diagram *d2target.Diagram, ruler *textmeasure.Ruler, svg string) (string, int, int) {
 	tl, br := diagram.BoundingBox()
 
@@ -171,7 +199,7 @@ func generateAppendix(diagram *d2target.Diagram, ruler *textmeasure.Ruler, svg s
 	i := 1
 
 	for _, s := range diagram.Shapes {
-		for _, txt := range []string{s.Tooltip, s.Link} {
+		for _, txt := range []string{s.Tooltip, transformInternalLink(diagram.Name, s.Link)} {
 			if txt != "" {
 				line, w, h := generateLine(i, br.Y+(PAD_TOP*2)+totalHeight, txt, ruler)
 				i++

d2renderers/d2svg/appendix/appendix_test.go

@@ -90,6 +90,23 @@ x -> y
 			script: `x: { link: https://d2lang.com }
 			y: { link: https://fosny.eu; tooltip: Gee, I feel kind of LIGHT in the head now,\nknowing I can't make my satellite dish PAYMENTS! }
 x -> y
+`,
+		},
+		{
+			name: "internal-links",
+			script: `x: { link: layers.x }
+layers: {
+  x: {
+    gooo
+    home.link: _
+    next.link: steps.next
+    steps: {
+      next: {
+          hi
+      }
+    }
+  }
+}
 `,
 		},
 		{