module Code_group_order: sig .. end
type select_single_op_fn = Code_selection_context.code_selection_context ->
       Algebra_type.algop_expr -> Code_selection_context.code_selection_context 
val build_order_by_code : Code_selection_context.code_selection_context ->
       Algebra_type.algop_expr ->
       Xquery_common_ast.stablekind *
       (Xquery_common_ast.sortkind * Xquery_common_ast.emptysortkind) list *
       Xquery_algebra_ast.aoverloaded_signature_table ->
       Algebra_type.alg_eval_code_dep *
       Code_selection_context.code_selection_context
val build_group_code : Code_selection_context.code_selection_context ->
       Algebra_type.algop_expr ->
       select_single_op_fn ->
       Xquery_algebra_ast.group_desc list ->
       Algebra_type.alg_eval_code_dep *
       Code_selection_context.code_selection_context