class Prism::SingletonClassNode

Represents a singleton class declaration involving the ‘class` keyword.

class << self end
^^^^^^^^^^^^^^^^^

Attributes

body[R]

attr_reader body: Prism::node?

expression[R]

attr_reader expression: Prism::node

locals[R]

attr_reader locals: Array

Public Class Methods

new(source, locals, class_keyword_loc, operator_loc, expression, body, end_keyword_loc, location) click to toggle source

def initialize: (Array locals, Location class_keyword_loc, Location operator_loc, Prism::node expression, Prism::node? body, Location end_keyword_loc, Location location) -> void

# File lib/prism/node.rb, line 16903
def initialize(source, locals, class_keyword_loc, operator_loc, expression, body, end_keyword_loc, location)
  @source = source
  @newline = false
  @location = location
  @locals = locals
  @class_keyword_loc = class_keyword_loc
  @operator_loc = operator_loc
  @expression = expression
  @body = body
  @end_keyword_loc = end_keyword_loc
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 17025
def self.type
  :singleton_class_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 17031
def ===(other)
  other.is_a?(SingletonClassNode) &&
    (locals.length == other.locals.length) &&
    locals.zip(other.locals).all? { |left, right| left === right } &&
    (class_keyword_loc.nil? == other.class_keyword_loc.nil?) &&
    (operator_loc.nil? == other.operator_loc.nil?) &&
    (expression === other.expression) &&
    (body === other.body) &&
    (end_keyword_loc.nil? == other.end_keyword_loc.nil?)
end

accept(visitor) click to toggle source

def accept: (Visitor visitor) -> void

# File lib/prism/node.rb, line 16916
def accept(visitor)
  visitor.visit_singleton_class_node(self)
end

child_nodes() click to toggle source

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

# File lib/prism/node.rb, line 16921
def child_nodes
  [expression, body]
end

Also aliased as: deconstruct

class_keyword() click to toggle source

def class_keyword: () -> String

# File lib/prism/node.rb, line 16982
def class_keyword
  class_keyword_loc.slice
end

class_keyword_loc() click to toggle source

attr_reader class_keyword_loc: Location

# File lib/prism/node.rb, line 16955
def class_keyword_loc
  location = @class_keyword_loc
  return location if location.is_a?(Location)
  @class_keyword_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF)
end

comment_targets() click to toggle source

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

# File lib/prism/node.rb, line 16934
def comment_targets
  [class_keyword_loc, operator_loc, expression, *body, end_keyword_loc] #: Array[Prism::node | Location]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File lib/prism/node.rb, line 16926
def compact_child_nodes
  compact = [] #: Array[Prism::node]
  compact << expression
  compact << body if body
  compact
end

copy(locals: self.locals, class_keyword_loc: self.class_keyword_loc, operator_loc: self.operator_loc, expression: self.expression, body: self.body, end_keyword_loc: self.end_keyword_loc, location: self.location) click to toggle source

def copy: (?locals: Array, ?class_keyword_loc: Location, ?operator_loc: Location, ?expression: Prism::node, ?body: Prism::node?, ?end_keyword_loc: Location, ?location: Location) -> SingletonClassNode

# File lib/prism/node.rb, line 16939
def copy(locals: self.locals, class_keyword_loc: self.class_keyword_loc, operator_loc: self.operator_loc, expression: self.expression, body: self.body, end_keyword_loc: self.end_keyword_loc, location: self.location)
  SingletonClassNode.new(source, locals, class_keyword_loc, operator_loc, expression, body, end_keyword_loc, location)
end

deconstruct()

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

Alias for: child_nodes

deconstruct_keys(keys) click to toggle source

def deconstruct_keys: (Array keys) -> { locals: Array, class_keyword_loc: Location, operator_loc: Location, expression: Prism::node, body: Prism::node?, end_keyword_loc: Location, location: Location }

# File lib/prism/node.rb, line 16947
def deconstruct_keys(keys)
  { locals: locals, class_keyword_loc: class_keyword_loc, operator_loc: operator_loc, expression: expression, body: body, end_keyword_loc: end_keyword_loc, location: location }
end

end_keyword() click to toggle source

def end_keyword: () -> String

# File lib/prism/node.rb, line 16992
def end_keyword
  end_keyword_loc.slice
end

end_keyword_loc() click to toggle source

attr_reader end_keyword_loc: Location

# File lib/prism/node.rb, line 16975
def end_keyword_loc
  location = @end_keyword_loc
  return location if location.is_a?(Location)
  @end_keyword_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF)
end

inspect() click to toggle source

def inspect -> String

# File lib/prism/node.rb, line 16997
def inspect
  InspectVisitor.compose(self)
end

operator() click to toggle source

def operator: () -> String

# File lib/prism/node.rb, line 16987
def operator
  operator_loc.slice
end

operator_loc() click to toggle source

attr_reader operator_loc: Location

# File lib/prism/node.rb, line 16962
def operator_loc
  location = @operator_loc
  return location if location.is_a?(Location)
  @operator_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF)
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 17015
def type
  :singleton_class_node
end