class Prism::UndefNode

Represents the use of the ‘undef` keyword.

undef :foo, :bar, :baz



attr_reader names: Array[SymbolNode | InterpolatedSymbolNode]

Public Class Methods

new(source, names, keyword_loc, location) click to toggle source

def initialize: (Array[SymbolNode | InterpolatedSymbolNode] names, Location keyword_loc, Location location) -> void

# File lib/prism/node.rb, line 17814
def initialize(source, names, keyword_loc, location)
  @source = source
  @newline = false
  @location = location
  @names = names
  @keyword_loc = keyword_loc
type() click to toggle source

Similar to type, this method returns a symbol that you can use for splitting on the type of the node without having to do a long === chain. Note that like type, it will still be slower than using == for a single class, but should be faster in a case statement or an array comparison.

def self.type: () -> Symbol

# File lib/prism/node.rb, line 17903
def self.type

Public Instance Methods

accept(visitor) click to toggle source

def accept: (Visitor visitor) -> void

# File lib/prism/node.rb, line 17823
def accept(visitor)
child_nodes() click to toggle source

def child_nodes: () -> Array[nil | Node]

# File lib/prism/node.rb, line 17828
def child_nodes
Also aliased as: deconstruct
comment_targets() click to toggle source

def comment_targets: () -> Array[Node | Location]

# File lib/prism/node.rb, line 17838
def comment_targets
  [*names, keyword_loc] #: Array[Prism::node | Location]
compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File lib/prism/node.rb, line 17833
def compact_child_nodes
copy(names: self.names, keyword_loc: self.keyword_loc, location: self.location) click to toggle source

def copy: (?names: Array[SymbolNode | InterpolatedSymbolNode], ?keyword_loc: Location, ?location: Location) -> UndefNode

# File lib/prism/node.rb, line 17843
def copy(names: self.names, keyword_loc: self.keyword_loc, location: self.location), names, keyword_loc, location)

def deconstruct: () -> Array[nil | Node]

Alias for: child_nodes
deconstruct_keys(keys) click to toggle source

def deconstruct_keys: (Array keys) -> { names: Array[SymbolNode | InterpolatedSymbolNode], keyword_loc: Location, location: Location }

# File lib/prism/node.rb, line 17851
def deconstruct_keys(keys)
  { names: names, keyword_loc: keyword_loc, location: location }
inspect(inspector = click to toggle source

def inspect(NodeInspector inspector) -> String

# File lib/prism/node.rb, line 17872
def inspect(inspector =
  inspector << inspector.header(self)
  inspector << "├── names: #{inspector.list("#{inspector.prefix}│   ", names)}"
  inspector << "└── keyword_loc: #{inspector.location(keyword_loc)}\n"
keyword() click to toggle source

def keyword: () -> String

# File lib/prism/node.rb, line 17867
def keyword
keyword_loc() click to toggle source

attr_reader keyword_loc: Location

# File lib/prism/node.rb, line 17859
def keyword_loc
  location = @keyword_loc
  return location if location.is_a?(Location)
  @keyword_loc =, location >> 32, location & 0xFFFFFFFF)
type() click to toggle source

Sometimes you want to check an instance of a node against a list of classes to see what kind of behavior to perform. Usually this is done by calling ‘[cls1, cls2].include?(node.class)` or putting the node into a case statement and doing `case node; when cls1; when cls2; end`. Both of these approaches are relatively slow because of the constant lookups, method calls, and/or array allocations.

Instead, you can call type, which will return to you a symbol that you can use for comparison. This is faster than the other approaches because it uses a single integer comparison, but also because if you’re on CRuby you can take advantage of the fact that case statements with all symbol keys will use a jump table.

def type: () -> Symbol

# File lib/prism/node.rb, line 17893
def type