Extractor: fix child index values

extractor/src/extractor.rs

@@ -232,8 +232,8 @@ impl Visitor<'_> {
                         )
                     }
                 }
-                Storage::Table { index } => {
-                    for child_id in child_ids {
+                Storage::Table => {
+                    for (index, child_id) in child_ids.iter().enumerate() {
                         self.trap_output.push(TrapEntry::ChildOf(
                             node_type_name(&field.parent.kind, field.parent.named),
                             parent_id,
@@ -241,7 +241,7 @@ impl Visitor<'_> {
                                 Some(name) => name.to_owned(),
                                 None => "child".to_owned(),
                             },
-                            Index(*index),
+                            Index(index),
                             *child_id,
                         ));
                     }

node-types/src/lib.rs

@@ -38,9 +38,7 @@ pub enum Storage {
     /// the field is stored as a column in the parent table
     Column,
     // the field is store in a link table
-    Table {
-        index: usize,
-    },
+    Table,
 }
 
 pub fn read_node_types(node_types_path: &Path) -> std::io::Result<Vec<Entry>> {
@@ -123,9 +121,7 @@ fn add_field(
     } else {
         // This field can appear zero or multiple times, so put
         // it in an auxiliary table.
-        storage = Storage::Table {
-            index: fields.len(),
-        };
+        storage = Storage::Table;
     }
     fields.push(Field {
         parent: TypeName {