Module fold

Transformation of an owned AST.

Each method of the Fold trait is a hook that can be overridden to customize the behavior when transforming the corresponding type of node. By default, every method recursively transforms the substructure of the input by invoking the right folder method on each of its fields.

pub trait Fold<T: AstInfo, T2: AstInfo> {
    /* ... */

    fn fold_function(&mut self, node: Function<T>) -> Function<T2> {
        fold_function(self, node)
    }

    /* ... */
}

pub fn fold_function<F, T: AstInfo, T2: AstInfo>(folder: &mut F, node: Function<T>) -> Function<T2>
where
    F: Fold<T, T2> + ?Sized,
{
    Function {
        name: folder.fold_item_name(node.name),
        args: folder.fold_function_args(node.args),
        filter: node.filter.map(|filter| Box::new(folder.fold_expr(*filter))),
        over: node.over.map(|over| folder.fold_window_spec(over)),
        distinct: node.distinct,
   }
}

Of particular note to the fold transformation is its handling of the AST’s generic parameter. The Fold trait is defined so that references to T in the input are replaced by references to T2 in the output. If transformation of T is not required, implement Fold such that T and T2 refer to the same concrete type, and then provide trivial implementations of any methods that fold T’s associated types.

The FoldNode trait is implemented for every node in the AST and can be used to write generic functions that apply a Fold implementation to any node in the AST.

Implementation notes

This module is automatically generated by the crate’s build script. Changes to the AST will be automatically propagated to the fold transformation.

This approach to AST transformations is inspired by the syn crate. These module docs are directly derived from the syn::fold module docs.

Traits

Fold

FoldNode

Functions

fold_abbreviated_grant_or_revoke_statement

fold_abbreviated_grant_statement

fold_abbreviated_revoke_statement

fold_alter_cluster_action

fold_alter_cluster_statement

fold_alter_connection_action

fold_alter_connection_option

fold_alter_connection_option_name

fold_alter_connection_statement

fold_alter_default_privileges_statement

fold_alter_index_action

fold_alter_index_statement

fold_alter_network_policy_statement

fold_alter_object_rename_statement

fold_alter_object_swap_statement

fold_alter_owner_statement

fold_alter_retain_history_statement

fold_alter_role_option

fold_alter_role_statement

fold_alter_secret_statement

fold_alter_set_cluster_statement

fold_alter_sink_action

fold_alter_sink_statement

fold_alter_source_action

fold_alter_source_add_subsource_option

fold_alter_source_add_subsource_option_name

fold_alter_source_statement

fold_alter_system_reset_all_statement

fold_alter_system_reset_statement

fold_alter_system_set_statement

fold_alter_table_add_column_statement

fold_as_of

fold_assignment

fold_avro_doc_on

fold_avro_schema

fold_avro_schema_option

fold_avro_schema_option_name

fold_catalog_name

fold_close_statement

fold_cluster_alter_option

fold_cluster_alter_option_name

fold_cluster_alter_option_value

fold_cluster_alter_until_ready_option

fold_cluster_alter_until_ready_option_name

fold_cluster_feature

fold_cluster_feature_name

fold_cluster_option

fold_cluster_option_name

fold_cluster_schedule_option_value

fold_column_def

fold_column_name

fold_column_option

fold_column_option_def

fold_column_versioned

fold_comment_object_type

fold_comment_statement

fold_commit_statement

fold_connection_default_aws_privatelink

fold_connection_option

fold_connection_option_name

fold_continual_task_option

fold_continual_task_option_name

fold_continual_task_stmt

fold_copy_direction

fold_copy_option

fold_copy_option_name

fold_copy_relation

fold_copy_statement

fold_copy_target

fold_create_cluster_replica_statement

fold_create_cluster_statement

fold_create_connection_option

fold_create_connection_option_name

fold_create_connection_statement

fold_create_connection_type

fold_create_continual_task_statement

fold_create_continual_task_sugar

fold_create_database_statement

fold_create_index_statement

fold_create_materialized_view_statement

fold_create_network_policy_statement

fold_create_role_statement

fold_create_schema_statement

fold_create_secret_statement

fold_create_sink_connection

fold_create_sink_option

fold_create_sink_option_name

fold_create_sink_statement

fold_create_source_connection

fold_create_source_option

fold_create_source_option_name

fold_create_source_statement

fold_create_subsource_option

fold_create_subsource_option_name

fold_create_subsource_statement

fold_create_table_from_source_statement

fold_create_table_statement

fold_create_type_as

fold_create_type_list_option

fold_create_type_list_option_name

fold_create_type_map_option

fold_create_type_map_option_name

fold_create_type_statement

fold_create_view_statement

fold_create_webhook_source_body

fold_create_webhook_source_check

fold_create_webhook_source_check_options

fold_create_webhook_source_filter_header

fold_create_webhook_source_header

fold_create_webhook_source_include_headers

fold_create_webhook_source_map_header

fold_create_webhook_source_secret

fold_create_webhook_source_statement

fold_csr_config_option

fold_csr_config_option_name

fold_csr_connection

fold_csr_connection_avro

fold_csr_connection_protobuf

fold_csr_seed_avro

fold_csr_seed_protobuf

fold_csr_seed_protobuf_schema

fold_csv_columns

fold_cte

fold_cte_block

fold_cte_mut_rec

fold_cte_mut_rec_column_def

fold_date_time_field

fold_deallocate_statement

fold_declare_statement

fold_deferred_item_name

fold_delete_statement

fold_discard_statement

fold_discard_target

fold_distinct

fold_doc_on_identifier

fold_doc_on_schema

fold_drop_objects_statement

fold_drop_owned_statement

fold_execute_statement

fold_explain_format

fold_explain_plan_option

fold_explain_plan_option_name

fold_explain_plan_statement

fold_explain_pushdown_statement

fold_explain_sink_schema_for

fold_explain_sink_schema_statement

fold_explain_stage

fold_explain_timestamp_statement

fold_explainee

fold_expr

fold_external_reference_export

fold_external_references

fold_fetch_direction

fold_fetch_option

fold_fetch_option_name

fold_fetch_statement

fold_format

fold_format_specifier

fold_function

fold_function_args

fold_grant_privileges_statement

fold_grant_role_statement

fold_grant_target_all_specification

fold_grant_target_specification

fold_grant_target_specification_inner

fold_homogenizing_function

fold_ident

fold_ident_error

fold_if_exists_behavior

fold_index_option

fold_index_option_name

fold_insert_source

fold_insert_statement

fold_inspect_shard_statement

fold_interval_value

fold_is_expr_construct

fold_join

fold_join_constraint

fold_join_operator

fold_kafka_broker

fold_kafka_broker_aws_privatelink

fold_kafka_broker_aws_privatelink_option

fold_kafka_broker_aws_privatelink_option_name

fold_kafka_broker_tunnel

fold_kafka_sink_config_option

fold_kafka_sink_config_option_name

fold_kafka_sink_key

fold_kafka_source_config_option

fold_kafka_source_config_option_name

fold_key_constraint

fold_limit

fold_load_generator

fold_load_generator_option

fold_load_generator_option_name

fold_map_entry

fold_materialized_view_option

fold_materialized_view_option_name

fold_mut_rec_block

fold_mut_rec_block_option

fold_mut_rec_block_option_name

fold_my_sql_config_option

fold_my_sql_config_option_name

fold_named_plan

fold_network_policy_option

fold_network_policy_option_name

fold_network_policy_rule_definition

fold_network_policy_rule_option

fold_network_policy_rule_option_name

fold_notice_severity

fold_object_type

fold_op

fold_order_by_expr

fold_pg_config_option

fold_pg_config_option_name

fold_prepare_statement

fold_privilege

fold_privilege_specification

fold_protobuf_schema

fold_qualified_replica

fold_query

fold_raise_statement

fold_reader_schema_selection_strategy

fold_reassign_owned_statement

fold_refresh_at_option_value

fold_refresh_every_option_value

fold_refresh_option_value

fold_replica_definition

fold_replica_option

fold_replica_option_name

fold_reset_variable_statement

fold_revoke_privileges_statement

fold_revoke_role_statement

fold_role_attribute

fold_rollback_statement

fold_schema

fold_select

fold_select_item

fold_select_option

fold_select_option_name

fold_select_statement

fold_set_expr

fold_set_operator

fold_set_role_var

fold_set_transaction_statement

fold_set_variable_statement

fold_set_variable_to

fold_set_variable_value

fold_show_columns_statement

fold_show_create_cluster_statement

fold_show_create_connection_statement

fold_show_create_index_statement

fold_show_create_materialized_view_statement

fold_show_create_sink_statement

fold_show_create_source_statement

fold_show_create_table_statement

fold_show_create_view_statement

fold_show_object_type

fold_show_objects_statement

fold_show_statement

fold_show_statement_filter

fold_show_variable_statement

fold_sink_envelope

fold_source_envelope

fold_source_error_policy

fold_source_include_metadata

fold_sql_server_config_option

fold_sql_server_config_option_name

fold_start_transaction_statement

fold_statement

fold_subscribe_option

fold_subscribe_option_name

fold_subscribe_output

fold_subscribe_relation

fold_subscribe_statement

fold_subscript_position

fold_system_object_type

fold_table_alias

fold_table_constraint

fold_table_factor

fold_table_from_source_columns

fold_table_from_source_option

fold_table_from_source_option_name

fold_table_option

fold_table_option_name

fold_table_with_joins

fold_target_role_specification

fold_transaction_access_mode

fold_transaction_isolation_level

fold_transaction_mode

fold_unresolved_database_name

fold_unresolved_item_name

fold_unresolved_object_name

fold_unresolved_schema_name

fold_update_statement

fold_validate_connection_statement

fold_value

fold_value_error

fold_values

fold_version

fold_view_definition

fold_window_frame

fold_window_frame_bound

fold_window_frame_units

fold_window_spec

fold_with_option_value