Move AST nodes into each item's struct

crates/frontend/src/ast.rs

@@ -75,20 +75,17 @@ pub fn items<'db>(db: &'db dyn Database, file: workspace::File) -> Vec<ItemMeta<
 }
 
 /// Parses an [ItemMeta] into its corresponding [Item].
-pub fn item<'db>(db: &'db dyn Database, meta: ItemMeta<'db>) -> WithAst<Item<'db>> {
-    use Item::*;
-
+pub fn item<'db>(db: &'db dyn Database, meta: ItemMeta<'db>) -> Item<'db> {
     let ast = meta.ast(db);
 
-    let item = match meta.kind(db) {
+    use Item::*;
+    match meta.kind(db) {
         ItemKind::Relation => Relation(relation(db, ast)),
         ItemKind::TypeAlias => TypeAlias(type_alias(db, ast)),
         ItemKind::Import => Import(import(db, ast)),
         ItemKind::Rule => Rule(rule(db, ast)),
         ItemKind::Assumption => Assumption(assumption(db, ast)),
-    };
-
-    WithAst::new(ast, item)
+    }
 }
 
 /// Common information on top-level items.