fix rust ast tool

tools/src/main.rs

@@ -90,7 +90,8 @@ fn main() {
 
     for item in &syntax.items {
         if let Item::Use(item_use) = item {
-            let path = path_to_string(&item_use.tree);
+            let path = use_tree_to_string(&item_use.tree);
+
             decls.push(RustDecl {
                 name: path.clone(),
                 type_: "import".to_string(),
@@ -376,3 +377,20 @@ fn generic_param_to_string(param: &syn::GenericParam) -> String {
         syn::GenericParam::Const(cnst) => cnst.ident.to_string(),
     }
 }
+
+fn use_tree_to_string(tree: &syn::UseTree) -> String {
+    match tree {
+        syn::UseTree::Path(p) => {
+            let base = p.ident.to_string();
+            let nested = use_tree_to_string(&*p.tree);
+            format!("{}::{}", base, nested)
+        }
+        syn::UseTree::Name(n) => n.ident.to_string(),
+        syn::UseTree::Rename(r) => r.ident.to_string(),
+        syn::UseTree::Glob(_) => "*".to_string(),
+        syn::UseTree::Group(g) => {
+            let items: Vec<String> = g.items.iter().map(use_tree_to_string).collect();
+            items.join("::")
+        }
+    }
+}