class Prism::NumberedReferenceReadNode

Represents reading a numbered reference to a capture in the previous match.

$1
^^

Attributes

number[R]

The (1-indexed, from the left) number of the capture group. Numbered references that are too large result in this value being ‘0`.

$1          # number `1`

$5432       # number `5432`

$4294967296 # number `0`

Public Class Methods

new(source, number, location) click to toggle source

def initialize: (Integer number, Location location) -> void

# File lib/prism/node.rb, line 14070
def initialize(source, number, location)
  @source = source
  @newline = false
  @location = location
  @number = number
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 lib/prism/node.rb, line 14148
def self.type
  :numbered_reference_read_node
end

Public Instance Methods

===(other) click to toggle source

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

# File lib/prism/node.rb, line 14154
def ===(other)
  other.is_a?(NumberedReferenceReadNode) &&
    (number === other.number)
end

accept(visitor) click to toggle source

def accept: (Visitor visitor) -> void

# File lib/prism/node.rb, line 14078
def accept(visitor)
  visitor.visit_numbered_reference_read_node(self)
end

child_nodes() click to toggle source

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

# File lib/prism/node.rb, line 14083
def child_nodes
  []
end

Also aliased as: deconstruct

comment_targets() click to toggle source

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

# File lib/prism/node.rb, line 14093
def comment_targets
  [] #: Array[Prism::node | Location]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File lib/prism/node.rb, line 14088
def compact_child_nodes
  []
end

copy(number: self.number, location: self.location) click to toggle source

def copy: (?number: Integer, ?location: Location) -> NumberedReferenceReadNode

# File lib/prism/node.rb, line 14098
def copy(number: self.number, location: self.location)
  NumberedReferenceReadNode.new(source, number, location)
end

deconstruct()

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

Alias for: child_nodes

deconstruct_keys(keys) click to toggle source

def deconstruct_keys: (Array keys) -> { number: Integer, location: Location }

# File lib/prism/node.rb, line 14106
def deconstruct_keys(keys)
  { number: number, location: location }
end

inspect() click to toggle source

def inspect -> String

# File lib/prism/node.rb, line 14120
def inspect
  InspectVisitor.compose(self)
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 lib/prism/node.rb, line 14138
def type
  :numbered_reference_read_node
end