class Prism::NilNode

Represents the use of the ‘nil` keyword.

nil
^^^

Public Class Methods

new(location) click to toggle source

def initialize: (location: Location) -> void

# File prism/node.rb, line 12493
def initialize(location)
  @location = location
end
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 prism/node.rb, line 12562
def self.type
  :nil_node
end

Public Instance Methods

accept(visitor) click to toggle source

def accept: (visitor: Visitor) -> void

# File prism/node.rb, line 12498
def accept(visitor)
  visitor.visit_nil_node(self)
end
child_nodes() click to toggle source

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

# File prism/node.rb, line 12503
def child_nodes
  []
end
Also aliased as: deconstruct
comment_targets() click to toggle source

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

# File prism/node.rb, line 12513
def comment_targets
  []
end
compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File prism/node.rb, line 12508
def compact_child_nodes
  []
end
copy(**params) click to toggle source

def copy: (**params) -> NilNode

# File prism/node.rb, line 12518
def copy(**params)
  NilNode.new(
    params.fetch(:location) { location },
  )
end
deconstruct()

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

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

def deconstruct_keys: (keys: Array) -> Hash[Symbol, nil | Node | Array | String | Token | Array | Location]

# File prism/node.rb, line 12528
def deconstruct_keys(keys)
  { location: location }
end
inspect(inspector = NodeInspector.new) click to toggle source

def inspect(inspector: NodeInspector) -> String

# File prism/node.rb, line 12533
def inspect(inspector = NodeInspector.new)
  inspector << inspector.header(self)
  inspector.to_str
end
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 prism/node.rb, line 12552
def type
  :nil_node
end