class Prism::UndefNode

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

# File prism/node.rb, line 17989
def initialize(source, names, keyword_loc, location)
  @source = source
  @location = location
  @names = names
  @keyword_loc = keyword_loc
end

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 prism/node.rb, line 18073
def self.type
  :undef_node
end

Implements case-equality for the node. This is effectively == but without comparing the value of locations. Locations are checked only for presence.

# File prism/node.rb, line 18079
def ===(other)
  other.is_a?(UndefNode) &&
    (names.length == other.names.length) &&
    names.zip(other.names).all? { |left, right| left === right } &&
    (keyword_loc.nil? == other.keyword_loc.nil?)
end

def accept: (Visitor visitor) -> void

# File prism/node.rb, line 17997
def accept(visitor)
  visitor.visit_undef_node(self)
end

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

# File prism/node.rb, line 18002
def child_nodes
  [*names]
end

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

# File prism/node.rb, line 18012
def comment_targets
  [*names, keyword_loc] #: Array[Prism::node | Location]
end

def compact_child_nodes: () -> Array

# File prism/node.rb, line 18007
def compact_child_nodes
  [*names]
end

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

# File prism/node.rb, line 18017
def copy(names: self.names, keyword_loc: self.keyword_loc, location: self.location)
  UndefNode.new(source, names, keyword_loc, location)
end

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

# File prism/node.rb, line 18025
def deconstruct_keys(keys)
  { names: names, keyword_loc: keyword_loc, location: location }
end

def inspect -> String

# File prism/node.rb, line 18045
def inspect
  InspectVisitor.compose(self)
end

def keyword: () -> String

# File prism/node.rb, line 18040
def keyword
  keyword_loc.slice
end

attr_reader keyword_loc: Location

# File prism/node.rb, line 18033
def keyword_loc
  location = @keyword_loc
  return location if location.is_a?(Location)
  @keyword_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF)
end

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 prism/node.rb, line 18063
def type
  :undef_node
end