class Prism::AlternationPatternNode
Represents an alternation pattern in pattern matching.
foo => bar | baz ^^^^^^^^^
Attributes
attr_reader left: Prism::node
attr_reader right: Prism::node
Public Class Methods
def initialize: (Prism::node left, Prism::node right, Location
operator_loc
, Location
location) -> void
# File prism/node.rb, line 403 def initialize(source, left, right, operator_loc, location) @source = source @location = location @left = left @right = right @operator_loc = operator_loc 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 491 def self.type :alternation_pattern_node end
Public Instance Methods
Implements case-equality for the node. This is effectively == but without comparing the value of locations. Locations are checked only for presence.
# File prism/node.rb, line 497 def ===(other) other.is_a?(AlternationPatternNode) && (left === other.left) && (right === other.right) && (operator_loc.nil? == other.operator_loc.nil?) end
def accept: (Visitor
visitor) -> void
# File prism/node.rb, line 412 def accept(visitor) visitor.visit_alternation_pattern_node(self) end
def child_nodes
: () -> Array[nil | Node]
# File prism/node.rb, line 417 def child_nodes [left, right] end
def comment_targets
: () -> Array[Node | Location]
# File prism/node.rb, line 427 def comment_targets [left, right, operator_loc] #: Array[Prism::node | Location] end
def compact_child_nodes
: () -> Array
# File prism/node.rb, line 422 def compact_child_nodes [left, right] end
def copy: (?left: Prism::node, ?right: Prism::node, ?operator_loc: Location
, ?location: Location
) -> AlternationPatternNode
# File prism/node.rb, line 432 def copy(left: self.left, right: self.right, operator_loc: self.operator_loc, location: self.location) AlternationPatternNode.new(source, left, right, operator_loc, location) end
def deconstruct_keys
: (Array keys) -> { left: Prism::node, right: Prism::node, operator_loc
: Location
, location: Location
}
# File prism/node.rb, line 440 def deconstruct_keys(keys) { left: left, right: right, operator_loc: operator_loc, location: location } end
def inspect -> String
# File prism/node.rb, line 463 def inspect InspectVisitor.compose(self) end
def operator: () -> String
# File prism/node.rb, line 458 def operator operator_loc.slice end
attr_reader operator_loc
: Location
# File prism/node.rb, line 451 def operator_loc location = @operator_loc return location if location.is_a?(Location) @operator_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF) 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 481 def type :alternation_pattern_node end