BE-607: HashQL: Refactor ModuleRegistry into builder/immutable split with allocator-generic stdlib construction

libs/@local/hashql/ast/src/lower/expander/error.rs

@@ -358,9 +358,19 @@ impl Display for FormatUserPath<'_, '_> {
 fn format_absolute_path<'heap>(item: &Item<'heap>, registry: &ModuleRegistry<'heap>) -> String {
     use core::iter;
 
-    let path = item.absolute_path(registry).into_iter().map(Symbol::unwrap);
+    #[expect(
+        clippy::needless_collect,
+        reason = "debugging code + required for reverse"
+    )]
+    let path: Vec<_> = item
+        .absolute_path_rev(registry)
+        .map(Symbol::unwrap)
+        .collect();
 
-    iter::once("").chain(path).intersperse("::").collect()
+    iter::once("")
+        .chain(path.into_iter().rev())
+        .intersperse("::")
+        .collect()
 }
 
 struct SpellingSuggestions<'heap, I> {

libs/@local/hashql/core/src/lib.rs

@@ -38,7 +38,8 @@
     step_trait,
     sync_nonpoison,
     try_trait_v2,
-    variant_count
+    variant_count,
+    maybe_uninit_fill
 )]
 
 extern crate alloc;

libs/@local/hashql/core/src/module/item.rs

@@ -76,6 +76,7 @@ pub struct Item<'heap> {
 }
 
 impl<'heap> Item<'heap> {
+    #[must_use]
     pub fn ancestors(
         &self,
         registry: &ModuleRegistry<'heap>,
@@ -87,27 +88,14 @@ impl<'heap> Item<'heap> {
                 return None;
             }
 
-            let module = registry.modules.index(next);
+            let module = registry.modules[next];
             next = module.parent;
 
             Some(module)
         })
     }
 
-    // TODO: deprecate
-    pub fn absolute_path(
-        &self,
-        registry: &ModuleRegistry<'heap>,
-    ) -> impl IntoIterator<Item = Symbol<'heap>> {
-        let mut modules: Vec<_> = self.ancestors(registry).into_iter().collect();
-        modules.reverse();
-
-        modules
-            .into_iter()
-            .map(|module| module.name)
-            .chain(iter::once(self.name))
-    }
-
+    #[must_use]
     pub fn absolute_path_rev(
         &self,
         registry: &ModuleRegistry<'heap>,