class Prism::SourceEncodingNode
Represents the use of the ‘__ENCODING__` keyword.
__ENCODING__ ^^^^^^^^^^^^
Public Class Methods
def initialize: (location: Location
) -> void
# File prism/node.rb, line 15424 def initialize(location) @location = location 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 15493 def self.type :source_encoding_node end
Public Instance Methods
def accept: (visitor: Visitor
) -> void
# File prism/node.rb, line 15429 def accept(visitor) visitor.visit_source_encoding_node(self) end
def child_nodes
: () -> Array[nil | Node]
# File prism/node.rb, line 15434 def child_nodes [] end
def comment_targets
: () -> Array[Node | Location]
# File prism/node.rb, line 15444 def comment_targets [] end
def compact_child_nodes
: () -> Array
# File prism/node.rb, line 15439 def compact_child_nodes [] end
def copy: (**params) -> SourceEncodingNode
# File prism/node.rb, line 15449 def copy(**params) SourceEncodingNode.new( params.fetch(:location) { location }, ) end
def inspect(inspector: NodeInspector) -> String
# File prism/node.rb, line 15464 def inspect(inspector = NodeInspector.new) inspector << inspector.header(self) 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 prism/node.rb, line 15483 def type :source_encoding_node end