class Prism::ClassVariableReadNode
Represents referencing a class variable.
@@foo ^^^^^
Attributes
The name of the class variable, which is a ‘@@` followed by an [identifier](github.com/ruby/prism/blob/main/docs/parsing_rules.md#identifiers).
@@abc # name `:@@abc` @@_test # name `:@@_test`
Public Class Methods
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 4157 def self.type :class_variable_read_node end
Public Instance Methods
def accept: (Visitor
visitor) -> void
# File lib/prism/node.rb, line 4086 def accept(visitor) visitor.visit_class_variable_read_node(self) end
def child_nodes
: () -> Array[nil | Node]
# File lib/prism/node.rb, line 4091 def child_nodes [] end
def comment_targets
: () -> Array[Node | Location]
# File lib/prism/node.rb, line 4101 def comment_targets [] #: Array[Prism::node | Location] end
def compact_child_nodes
: () -> Array
# File lib/prism/node.rb, line 4096 def compact_child_nodes [] end
def copy: (?name: Symbol
, ?location: Location
) -> ClassVariableReadNode
# File lib/prism/node.rb, line 4106 def copy(name: self.name, location: self.location) ClassVariableReadNode.new(source, name, location) end
def deconstruct_keys
: (Array keys) -> { name: Symbol
, location: Location
}
# File lib/prism/node.rb, line 4114 def deconstruct_keys(keys) { name: name, location: location } end
def inspect(NodeInspector inspector) -> String
# File lib/prism/node.rb, line 4127 def inspect(inspector = NodeInspector.new) inspector << inspector.header(self) inspector << "└── name: #{name.inspect}\n" inspector.to_str 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 lib/prism/node.rb, line 4147 def type :class_variable_read_node end