module Prism::Reflection

The Reflection module provides the ability to reflect on the structure of the syntax tree itself, as opposed to looking at a single syntax tree. This is useful in metaprogramming contexts.

Public Class Methods

fields_for(node) click to toggle source

Returns the fields for the given node.

# File prism/reflection.rb, line 104
def self.fields_for(node)
  case node.type
  when :alias_global_variable_node
    [NodeField.new(:new_name), NodeField.new(:old_name), LocationField.new(:keyword_loc)]
  when :alias_method_node
    [NodeField.new(:new_name), NodeField.new(:old_name), LocationField.new(:keyword_loc)]
  when :alternation_pattern_node
    [NodeField.new(:left), NodeField.new(:right), LocationField.new(:operator_loc)]
  when :and_node
    [NodeField.new(:left), NodeField.new(:right), LocationField.new(:operator_loc)]
  when :arguments_node
    [FlagsField.new(:flags, [:contains_keywords?, :contains_keyword_splat?]), NodeListField.new(:arguments)]
  when :array_node
    [FlagsField.new(:flags, [:contains_splat?]), NodeListField.new(:elements), OptionalLocationField.new(:opening_loc), OptionalLocationField.new(:closing_loc)]
  when :array_pattern_node
    [OptionalNodeField.new(:constant), NodeListField.new(:requireds), OptionalNodeField.new(:rest), NodeListField.new(:posts), OptionalLocationField.new(:opening_loc), OptionalLocationField.new(:closing_loc)]
  when :assoc_node
    [NodeField.new(:key), NodeField.new(:value), OptionalLocationField.new(:operator_loc)]
  when :assoc_splat_node
    [OptionalNodeField.new(:value), LocationField.new(:operator_loc)]
  when :back_reference_read_node
    [ConstantField.new(:name)]
  when :begin_node
    [OptionalLocationField.new(:begin_keyword_loc), OptionalNodeField.new(:statements), OptionalNodeField.new(:rescue_clause), OptionalNodeField.new(:else_clause), OptionalNodeField.new(:ensure_clause), OptionalLocationField.new(:end_keyword_loc)]
  when :block_argument_node
    [OptionalNodeField.new(:expression), LocationField.new(:operator_loc)]
  when :block_local_variable_node
    [FlagsField.new(:flags, [:repeated_parameter?]), ConstantField.new(:name)]
  when :block_node
    [ConstantListField.new(:locals), OptionalNodeField.new(:parameters), OptionalNodeField.new(:body), LocationField.new(:opening_loc), LocationField.new(:closing_loc)]
  when :block_parameter_node
    [FlagsField.new(:flags, [:repeated_parameter?]), OptionalConstantField.new(:name), OptionalLocationField.new(:name_loc), LocationField.new(:operator_loc)]
  when :block_parameters_node
    [OptionalNodeField.new(:parameters), NodeListField.new(:locals), OptionalLocationField.new(:opening_loc), OptionalLocationField.new(:closing_loc)]
  when :break_node
    [OptionalNodeField.new(:arguments), LocationField.new(:keyword_loc)]
  when :call_and_write_node
    [FlagsField.new(:flags, [:safe_navigation?, :variable_call?, :attribute_write?, :ignore_visibility?]), OptionalNodeField.new(:receiver), OptionalLocationField.new(:call_operator_loc), OptionalLocationField.new(:message_loc), ConstantField.new(:read_name), ConstantField.new(:write_name), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :call_node
    [FlagsField.new(:flags, [:safe_navigation?, :variable_call?, :attribute_write?, :ignore_visibility?]), OptionalNodeField.new(:receiver), OptionalLocationField.new(:call_operator_loc), ConstantField.new(:name), OptionalLocationField.new(:message_loc), OptionalLocationField.new(:opening_loc), OptionalNodeField.new(:arguments), OptionalLocationField.new(:closing_loc), OptionalNodeField.new(:block)]
  when :call_operator_write_node
    [FlagsField.new(:flags, [:safe_navigation?, :variable_call?, :attribute_write?, :ignore_visibility?]), OptionalNodeField.new(:receiver), OptionalLocationField.new(:call_operator_loc), OptionalLocationField.new(:message_loc), ConstantField.new(:read_name), ConstantField.new(:write_name), ConstantField.new(:binary_operator), LocationField.new(:binary_operator_loc), NodeField.new(:value)]
  when :call_or_write_node
    [FlagsField.new(:flags, [:safe_navigation?, :variable_call?, :attribute_write?, :ignore_visibility?]), OptionalNodeField.new(:receiver), OptionalLocationField.new(:call_operator_loc), OptionalLocationField.new(:message_loc), ConstantField.new(:read_name), ConstantField.new(:write_name), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :call_target_node
    [FlagsField.new(:flags, [:safe_navigation?, :variable_call?, :attribute_write?, :ignore_visibility?]), NodeField.new(:receiver), LocationField.new(:call_operator_loc), ConstantField.new(:name), LocationField.new(:message_loc)]
  when :capture_pattern_node
    [NodeField.new(:value), NodeField.new(:target), LocationField.new(:operator_loc)]
  when :case_match_node
    [OptionalNodeField.new(:predicate), NodeListField.new(:conditions), OptionalNodeField.new(:consequent), LocationField.new(:case_keyword_loc), LocationField.new(:end_keyword_loc)]
  when :case_node
    [OptionalNodeField.new(:predicate), NodeListField.new(:conditions), OptionalNodeField.new(:consequent), LocationField.new(:case_keyword_loc), LocationField.new(:end_keyword_loc)]
  when :class_node
    [ConstantListField.new(:locals), LocationField.new(:class_keyword_loc), NodeField.new(:constant_path), OptionalLocationField.new(:inheritance_operator_loc), OptionalNodeField.new(:superclass), OptionalNodeField.new(:body), LocationField.new(:end_keyword_loc), ConstantField.new(:name)]
  when :class_variable_and_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :class_variable_operator_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:binary_operator_loc), NodeField.new(:value), ConstantField.new(:binary_operator)]
  when :class_variable_or_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :class_variable_read_node
    [ConstantField.new(:name)]
  when :class_variable_target_node
    [ConstantField.new(:name)]
  when :class_variable_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), NodeField.new(:value), LocationField.new(:operator_loc)]
  when :constant_and_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :constant_operator_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:binary_operator_loc), NodeField.new(:value), ConstantField.new(:binary_operator)]
  when :constant_or_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :constant_path_and_write_node
    [NodeField.new(:target), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :constant_path_node
    [OptionalNodeField.new(:parent), OptionalConstantField.new(:name), LocationField.new(:delimiter_loc), LocationField.new(:name_loc)]
  when :constant_path_operator_write_node
    [NodeField.new(:target), LocationField.new(:binary_operator_loc), NodeField.new(:value), ConstantField.new(:binary_operator)]
  when :constant_path_or_write_node
    [NodeField.new(:target), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :constant_path_target_node
    [OptionalNodeField.new(:parent), OptionalConstantField.new(:name), LocationField.new(:delimiter_loc), LocationField.new(:name_loc)]
  when :constant_path_write_node
    [NodeField.new(:target), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :constant_read_node
    [ConstantField.new(:name)]
  when :constant_target_node
    [ConstantField.new(:name)]
  when :constant_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), NodeField.new(:value), LocationField.new(:operator_loc)]
  when :def_node
    [ConstantField.new(:name), LocationField.new(:name_loc), OptionalNodeField.new(:receiver), OptionalNodeField.new(:parameters), OptionalNodeField.new(:body), ConstantListField.new(:locals), LocationField.new(:def_keyword_loc), OptionalLocationField.new(:operator_loc), OptionalLocationField.new(:lparen_loc), OptionalLocationField.new(:rparen_loc), OptionalLocationField.new(:equal_loc), OptionalLocationField.new(:end_keyword_loc)]
  when :defined_node
    [OptionalLocationField.new(:lparen_loc), NodeField.new(:value), OptionalLocationField.new(:rparen_loc), LocationField.new(:keyword_loc)]
  when :else_node
    [LocationField.new(:else_keyword_loc), OptionalNodeField.new(:statements), OptionalLocationField.new(:end_keyword_loc)]
  when :embedded_statements_node
    [LocationField.new(:opening_loc), OptionalNodeField.new(:statements), LocationField.new(:closing_loc)]
  when :embedded_variable_node
    [LocationField.new(:operator_loc), NodeField.new(:variable)]
  when :ensure_node
    [LocationField.new(:ensure_keyword_loc), OptionalNodeField.new(:statements), LocationField.new(:end_keyword_loc)]
  when :false_node
    []
  when :find_pattern_node
    [OptionalNodeField.new(:constant), NodeField.new(:left), NodeListField.new(:requireds), NodeField.new(:right), OptionalLocationField.new(:opening_loc), OptionalLocationField.new(:closing_loc)]
  when :flip_flop_node
    [FlagsField.new(:flags, [:exclude_end?]), OptionalNodeField.new(:left), OptionalNodeField.new(:right), LocationField.new(:operator_loc)]
  when :float_node
    [FloatField.new(:value)]
  when :for_node
    [NodeField.new(:index), NodeField.new(:collection), OptionalNodeField.new(:statements), LocationField.new(:for_keyword_loc), LocationField.new(:in_keyword_loc), OptionalLocationField.new(:do_keyword_loc), LocationField.new(:end_keyword_loc)]
  when :forwarding_arguments_node
    []
  when :forwarding_parameter_node
    []
  when :forwarding_super_node
    [OptionalNodeField.new(:block)]
  when :global_variable_and_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :global_variable_operator_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:binary_operator_loc), NodeField.new(:value), ConstantField.new(:binary_operator)]
  when :global_variable_or_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :global_variable_read_node
    [ConstantField.new(:name)]
  when :global_variable_target_node
    [ConstantField.new(:name)]
  when :global_variable_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), NodeField.new(:value), LocationField.new(:operator_loc)]
  when :hash_node
    [LocationField.new(:opening_loc), NodeListField.new(:elements), LocationField.new(:closing_loc)]
  when :hash_pattern_node
    [OptionalNodeField.new(:constant), NodeListField.new(:elements), OptionalNodeField.new(:rest), OptionalLocationField.new(:opening_loc), OptionalLocationField.new(:closing_loc)]
  when :if_node
    [OptionalLocationField.new(:if_keyword_loc), NodeField.new(:predicate), OptionalLocationField.new(:then_keyword_loc), OptionalNodeField.new(:statements), OptionalNodeField.new(:consequent), OptionalLocationField.new(:end_keyword_loc)]
  when :imaginary_node
    [NodeField.new(:numeric)]
  when :implicit_node
    [NodeField.new(:value)]
  when :implicit_rest_node
    []
  when :in_node
    [NodeField.new(:pattern), OptionalNodeField.new(:statements), LocationField.new(:in_loc), OptionalLocationField.new(:then_loc)]
  when :index_and_write_node
    [FlagsField.new(:flags, [:safe_navigation?, :variable_call?, :attribute_write?, :ignore_visibility?]), OptionalNodeField.new(:receiver), OptionalLocationField.new(:call_operator_loc), LocationField.new(:opening_loc), OptionalNodeField.new(:arguments), LocationField.new(:closing_loc), OptionalNodeField.new(:block), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :index_operator_write_node
    [FlagsField.new(:flags, [:safe_navigation?, :variable_call?, :attribute_write?, :ignore_visibility?]), OptionalNodeField.new(:receiver), OptionalLocationField.new(:call_operator_loc), LocationField.new(:opening_loc), OptionalNodeField.new(:arguments), LocationField.new(:closing_loc), OptionalNodeField.new(:block), ConstantField.new(:binary_operator), LocationField.new(:binary_operator_loc), NodeField.new(:value)]
  when :index_or_write_node
    [FlagsField.new(:flags, [:safe_navigation?, :variable_call?, :attribute_write?, :ignore_visibility?]), OptionalNodeField.new(:receiver), OptionalLocationField.new(:call_operator_loc), LocationField.new(:opening_loc), OptionalNodeField.new(:arguments), LocationField.new(:closing_loc), OptionalNodeField.new(:block), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :index_target_node
    [FlagsField.new(:flags, [:safe_navigation?, :variable_call?, :attribute_write?, :ignore_visibility?]), NodeField.new(:receiver), LocationField.new(:opening_loc), OptionalNodeField.new(:arguments), LocationField.new(:closing_loc), OptionalNodeField.new(:block)]
  when :instance_variable_and_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :instance_variable_operator_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:binary_operator_loc), NodeField.new(:value), ConstantField.new(:binary_operator)]
  when :instance_variable_or_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :instance_variable_read_node
    [ConstantField.new(:name)]
  when :instance_variable_target_node
    [ConstantField.new(:name)]
  when :instance_variable_write_node
    [ConstantField.new(:name), LocationField.new(:name_loc), NodeField.new(:value), LocationField.new(:operator_loc)]
  when :integer_node
    [FlagsField.new(:flags, [:binary?, :decimal?, :octal?, :hexadecimal?]), IntegerField.new(:value)]
  when :interpolated_match_last_line_node
    [FlagsField.new(:flags, [:ignore_case?, :extended?, :multi_line?, :once?, :euc_jp?, :ascii_8bit?, :windows_31j?, :utf_8?, :forced_utf8_encoding?, :forced_binary_encoding?, :forced_us_ascii_encoding?]), LocationField.new(:opening_loc), NodeListField.new(:parts), LocationField.new(:closing_loc)]
  when :interpolated_regular_expression_node
    [FlagsField.new(:flags, [:ignore_case?, :extended?, :multi_line?, :once?, :euc_jp?, :ascii_8bit?, :windows_31j?, :utf_8?, :forced_utf8_encoding?, :forced_binary_encoding?, :forced_us_ascii_encoding?]), LocationField.new(:opening_loc), NodeListField.new(:parts), LocationField.new(:closing_loc)]
  when :interpolated_string_node
    [FlagsField.new(:flags, [:frozen?, :mutable?]), OptionalLocationField.new(:opening_loc), NodeListField.new(:parts), OptionalLocationField.new(:closing_loc)]
  when :interpolated_symbol_node
    [OptionalLocationField.new(:opening_loc), NodeListField.new(:parts), OptionalLocationField.new(:closing_loc)]
  when :interpolated_x_string_node
    [LocationField.new(:opening_loc), NodeListField.new(:parts), LocationField.new(:closing_loc)]
  when :it_parameters_node
    []
  when :keyword_hash_node
    [FlagsField.new(:flags, [:symbol_keys?]), NodeListField.new(:elements)]
  when :keyword_rest_parameter_node
    [FlagsField.new(:flags, [:repeated_parameter?]), OptionalConstantField.new(:name), OptionalLocationField.new(:name_loc), LocationField.new(:operator_loc)]
  when :lambda_node
    [ConstantListField.new(:locals), LocationField.new(:operator_loc), LocationField.new(:opening_loc), LocationField.new(:closing_loc), OptionalNodeField.new(:parameters), OptionalNodeField.new(:body)]
  when :local_variable_and_write_node
    [LocationField.new(:name_loc), LocationField.new(:operator_loc), NodeField.new(:value), ConstantField.new(:name), IntegerField.new(:depth)]
  when :local_variable_operator_write_node
    [LocationField.new(:name_loc), LocationField.new(:binary_operator_loc), NodeField.new(:value), ConstantField.new(:name), ConstantField.new(:binary_operator), IntegerField.new(:depth)]
  when :local_variable_or_write_node
    [LocationField.new(:name_loc), LocationField.new(:operator_loc), NodeField.new(:value), ConstantField.new(:name), IntegerField.new(:depth)]
  when :local_variable_read_node
    [ConstantField.new(:name), IntegerField.new(:depth)]
  when :local_variable_target_node
    [ConstantField.new(:name), IntegerField.new(:depth)]
  when :local_variable_write_node
    [ConstantField.new(:name), IntegerField.new(:depth), LocationField.new(:name_loc), NodeField.new(:value), LocationField.new(:operator_loc)]
  when :match_last_line_node
    [FlagsField.new(:flags, [:ignore_case?, :extended?, :multi_line?, :once?, :euc_jp?, :ascii_8bit?, :windows_31j?, :utf_8?, :forced_utf8_encoding?, :forced_binary_encoding?, :forced_us_ascii_encoding?]), LocationField.new(:opening_loc), LocationField.new(:content_loc), LocationField.new(:closing_loc), StringField.new(:unescaped)]
  when :match_predicate_node
    [NodeField.new(:value), NodeField.new(:pattern), LocationField.new(:operator_loc)]
  when :match_required_node
    [NodeField.new(:value), NodeField.new(:pattern), LocationField.new(:operator_loc)]
  when :match_write_node
    [NodeField.new(:call), NodeListField.new(:targets)]
  when :missing_node
    []
  when :module_node
    [ConstantListField.new(:locals), LocationField.new(:module_keyword_loc), NodeField.new(:constant_path), OptionalNodeField.new(:body), LocationField.new(:end_keyword_loc), ConstantField.new(:name)]
  when :multi_target_node
    [NodeListField.new(:lefts), OptionalNodeField.new(:rest), NodeListField.new(:rights), OptionalLocationField.new(:lparen_loc), OptionalLocationField.new(:rparen_loc)]
  when :multi_write_node
    [NodeListField.new(:lefts), OptionalNodeField.new(:rest), NodeListField.new(:rights), OptionalLocationField.new(:lparen_loc), OptionalLocationField.new(:rparen_loc), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :next_node
    [OptionalNodeField.new(:arguments), LocationField.new(:keyword_loc)]
  when :nil_node
    []
  when :no_keywords_parameter_node
    [LocationField.new(:operator_loc), LocationField.new(:keyword_loc)]
  when :numbered_parameters_node
    [IntegerField.new(:maximum)]
  when :numbered_reference_read_node
    [IntegerField.new(:number)]
  when :optional_keyword_parameter_node
    [FlagsField.new(:flags, [:repeated_parameter?]), ConstantField.new(:name), LocationField.new(:name_loc), NodeField.new(:value)]
  when :optional_parameter_node
    [FlagsField.new(:flags, [:repeated_parameter?]), ConstantField.new(:name), LocationField.new(:name_loc), LocationField.new(:operator_loc), NodeField.new(:value)]
  when :or_node
    [NodeField.new(:left), NodeField.new(:right), LocationField.new(:operator_loc)]
  when :parameters_node
    [NodeListField.new(:requireds), NodeListField.new(:optionals), OptionalNodeField.new(:rest), NodeListField.new(:posts), NodeListField.new(:keywords), OptionalNodeField.new(:keyword_rest), OptionalNodeField.new(:block)]
  when :parentheses_node
    [OptionalNodeField.new(:body), LocationField.new(:opening_loc), LocationField.new(:closing_loc)]
  when :pinned_expression_node
    [NodeField.new(:expression), LocationField.new(:operator_loc), LocationField.new(:lparen_loc), LocationField.new(:rparen_loc)]
  when :pinned_variable_node
    [NodeField.new(:variable), LocationField.new(:operator_loc)]
  when :post_execution_node
    [OptionalNodeField.new(:statements), LocationField.new(:keyword_loc), LocationField.new(:opening_loc), LocationField.new(:closing_loc)]
  when :pre_execution_node
    [OptionalNodeField.new(:statements), LocationField.new(:keyword_loc), LocationField.new(:opening_loc), LocationField.new(:closing_loc)]
  when :program_node
    [ConstantListField.new(:locals), NodeField.new(:statements)]
  when :range_node
    [FlagsField.new(:flags, [:exclude_end?]), OptionalNodeField.new(:left), OptionalNodeField.new(:right), LocationField.new(:operator_loc)]
  when :rational_node
    [NodeField.new(:numeric)]
  when :redo_node
    []
  when :regular_expression_node
    [FlagsField.new(:flags, [:ignore_case?, :extended?, :multi_line?, :once?, :euc_jp?, :ascii_8bit?, :windows_31j?, :utf_8?, :forced_utf8_encoding?, :forced_binary_encoding?, :forced_us_ascii_encoding?]), LocationField.new(:opening_loc), LocationField.new(:content_loc), LocationField.new(:closing_loc), StringField.new(:unescaped)]
  when :required_keyword_parameter_node
    [FlagsField.new(:flags, [:repeated_parameter?]), ConstantField.new(:name), LocationField.new(:name_loc)]
  when :required_parameter_node
    [FlagsField.new(:flags, [:repeated_parameter?]), ConstantField.new(:name)]
  when :rescue_modifier_node
    [NodeField.new(:expression), LocationField.new(:keyword_loc), NodeField.new(:rescue_expression)]
  when :rescue_node
    [LocationField.new(:keyword_loc), NodeListField.new(:exceptions), OptionalLocationField.new(:operator_loc), OptionalNodeField.new(:reference), OptionalNodeField.new(:statements), OptionalNodeField.new(:consequent)]
  when :rest_parameter_node
    [FlagsField.new(:flags, [:repeated_parameter?]), OptionalConstantField.new(:name), OptionalLocationField.new(:name_loc), LocationField.new(:operator_loc)]
  when :retry_node
    []
  when :return_node
    [FlagsField.new(:flags, [:redundant?]), LocationField.new(:keyword_loc), OptionalNodeField.new(:arguments)]
  when :self_node
    []
  when :shareable_constant_node
    [FlagsField.new(:flags, [:literal?, :experimental_everything?, :experimental_copy?]), NodeField.new(:write)]
  when :singleton_class_node
    [ConstantListField.new(:locals), LocationField.new(:class_keyword_loc), LocationField.new(:operator_loc), NodeField.new(:expression), OptionalNodeField.new(:body), LocationField.new(:end_keyword_loc)]
  when :source_encoding_node
    []
  when :source_file_node
    [FlagsField.new(:flags, [:forced_utf8_encoding?, :forced_binary_encoding?, :frozen?, :mutable?]), StringField.new(:filepath)]
  when :source_line_node
    []
  when :splat_node
    [LocationField.new(:operator_loc), OptionalNodeField.new(:expression)]
  when :statements_node
    [NodeListField.new(:body)]
  when :string_node
    [FlagsField.new(:flags, [:forced_utf8_encoding?, :forced_binary_encoding?, :frozen?, :mutable?]), OptionalLocationField.new(:opening_loc), LocationField.new(:content_loc), OptionalLocationField.new(:closing_loc), StringField.new(:unescaped)]
  when :super_node
    [LocationField.new(:keyword_loc), OptionalLocationField.new(:lparen_loc), OptionalNodeField.new(:arguments), OptionalLocationField.new(:rparen_loc), OptionalNodeField.new(:block)]
  when :symbol_node
    [FlagsField.new(:flags, [:forced_utf8_encoding?, :forced_binary_encoding?, :forced_us_ascii_encoding?]), OptionalLocationField.new(:opening_loc), OptionalLocationField.new(:value_loc), OptionalLocationField.new(:closing_loc), StringField.new(:unescaped)]
  when :true_node
    []
  when :undef_node
    [NodeListField.new(:names), LocationField.new(:keyword_loc)]
  when :unless_node
    [LocationField.new(:keyword_loc), NodeField.new(:predicate), OptionalLocationField.new(:then_keyword_loc), OptionalNodeField.new(:statements), OptionalNodeField.new(:consequent), OptionalLocationField.new(:end_keyword_loc)]
  when :until_node
    [FlagsField.new(:flags, [:begin_modifier?]), LocationField.new(:keyword_loc), OptionalLocationField.new(:closing_loc), NodeField.new(:predicate), OptionalNodeField.new(:statements)]
  when :when_node
    [LocationField.new(:keyword_loc), NodeListField.new(:conditions), OptionalLocationField.new(:then_keyword_loc), OptionalNodeField.new(:statements)]
  when :while_node
    [FlagsField.new(:flags, [:begin_modifier?]), LocationField.new(:keyword_loc), OptionalLocationField.new(:closing_loc), NodeField.new(:predicate), OptionalNodeField.new(:statements)]
  when :x_string_node
    [FlagsField.new(:flags, [:forced_utf8_encoding?, :forced_binary_encoding?]), LocationField.new(:opening_loc), LocationField.new(:content_loc), LocationField.new(:closing_loc), StringField.new(:unescaped)]
  when :yield_node
    [LocationField.new(:keyword_loc), OptionalLocationField.new(:lparen_loc), OptionalNodeField.new(:arguments), OptionalLocationField.new(:rparen_loc)]
  else
    raise "Unknown node type: #{node.type.inspect}"
  end
end