+ struct upkg_priv *pkg = (struct upkg_priv *)pub;
+
+ if (idx < pkg->pub.import_count)
+ return &pkg->imports[idx];
+ return NULL;
+}
+
+const char *upkg_export_class(struct upkg *pub, unsigned long idx,
+ const char **package)
+{
+ struct upkg_priv *pkg = (struct upkg_priv *)pub;
+ const struct upkg_import *iclass, *ipackage;
+ struct upkg_export_priv *export;
+ unsigned long pkg_idx;
+
+ if (idx >= pkg->pub.export_count)
+ return NULL;
+
+ export = &pkg->exports[idx];
+
+ /* Assumption: class references are always imports. */
+ format_assert(export->class <= 0, return NULL);
+
+ /* Get the class. */
+ if (export->class == 0) {
+ if (package) *package = "Core";
+ return "Class";
+ }
+
+ pkg_idx = -(export->class + 1);
+ if (pkg_idx >= pkg->pub.import_count)
+ return NULL;
+ iclass = &pkg->imports[pkg_idx];
+
+ /* Assumption: class references are always Core.Class. */
+ format_assert(!strcmp(iclass->class_package, "Core"), return NULL);
+ format_assert(!strcmp(iclass->class_name, "Class"), return NULL);
+
+ ipackage = iclass->parent;
+ if (!ipackage)
+ return NULL;
+
+ /* Assumption: package references are always Core.Package. */
+ format_assert(!strcmp(ipackage->class_package, "Core"), return NULL);
+ format_assert(!strcmp(ipackage->class_name, "Package"), return NULL);
+
+ if (package) *package = ipackage->name;
+ return iclass->name;
+}
+
+struct upkg_file *upkg_export_open(struct upkg *pub, unsigned long idx)
+{
+ struct upkg_priv *pkg = (struct upkg_priv *)pub;