feat: flatten array_expr_list (#32)

* feat: flatten array_expr_list

* fix: clippy

Author: tanzaku

crates/parser-generator/src/parser_generator/lalr.rs

@@ -250,9 +250,7 @@ impl Lalr {
                 .map(|c| id_mapper.to_component_id(&c))
                 .or_else(|| {
                     rule.components
-                        .iter()
-                        .filter(|c| matches!(c, Component::Terminal(_)))
-                        .next_back()
+                        .iter().rfind(|c| matches!(c, Component::Terminal(_)))
                         .map(|c| id_mapper.to_component_id(c))
                 })
                 .and_then(|component_id| assoc[component_id.0 as usize].clone());

crates/postgresql-cst-parser/src/tree_sitter/convert.rs

@@ -155,7 +155,8 @@ fn walk_and_build(
                     | SyntaxKind::insert_column_list
                     | SyntaxKind::index_params
                     | SyntaxKind::values_clause
-                    | SyntaxKind::TableFuncElementList) => {
+                    | SyntaxKind::TableFuncElementList
+                    | SyntaxKind::array_expr_list) => {
                         if parent_kind == child_kind {
                             // [Node: Flatten]
                             //
@@ -526,5 +527,15 @@ FROM
             let (new_root, _) = get_ts_tree_and_range_map(input, &root);
             assert_no_direct_nested_kind(&new_root, SyntaxKind::TableFuncElementList);
         }
+
+        #[test]
+        fn no_nested_array_expr_list() {
+            let input = "select array[[1,2],[3,4]];";
+            let root = cst::parse(input).unwrap();
+            assert_direct_nested_kind(&root, SyntaxKind::array_expr_list);
+
+            let (new_root, _) = get_ts_tree_and_range_map(input, &root);
+            assert_no_direct_nested_kind(&new_root, SyntaxKind::array_expr_list);
+        }
     }
 }