class Prism::MatchRequiredNode

Represents the use of the ‘=>` operator.

foo => bar
^^^^^^^^^^

Attributes

pattern[R]

attr_reader pattern: Prism::node

value[R]

attr_reader value: Prism::node

Public Class Methods

new(source, value, pattern, operator_loc, location) click to toggle source

def initialize: (Prism::node value, Prism::node pattern, Location operator_loc, Location location) -> void

# File prism/node.rb, line 12858
def initialize(source, value, pattern, operator_loc, location)
  @source = source
  @location = location
  @value = value
  @pattern = pattern
  @operator_loc = operator_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 prism/node.rb, line 12946
def self.type
  :match_required_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 prism/node.rb, line 12952
def ===(other)
  other.is_a?(MatchRequiredNode) &&
    (value === other.value) &&
    (pattern === other.pattern) &&
    (operator_loc.nil? == other.operator_loc.nil?)
end

accept(visitor) click to toggle source

def accept: (Visitor visitor) -> void

# File prism/node.rb, line 12867
def accept(visitor)
  visitor.visit_match_required_node(self)
end

child_nodes() click to toggle source

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

# File prism/node.rb, line 12872
def child_nodes
  [value, pattern]
end

Also aliased as: deconstruct

comment_targets() click to toggle source

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

# File prism/node.rb, line 12882
def comment_targets
  [value, pattern, operator_loc] #: Array[Prism::node | Location]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File prism/node.rb, line 12877
def compact_child_nodes
  [value, pattern]
end

copy(value: self.value, pattern: self.pattern, operator_loc: self.operator_loc, location: self.location) click to toggle source

def copy: (?value: Prism::node, ?pattern: Prism::node, ?operator_loc: Location, ?location: Location) -> MatchRequiredNode

# File prism/node.rb, line 12887
def copy(value: self.value, pattern: self.pattern, operator_loc: self.operator_loc, location: self.location)
  MatchRequiredNode.new(source, value, pattern, operator_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) -> { value: Prism::node, pattern: Prism::node, operator_loc: Location, location: Location }

# File prism/node.rb, line 12895
def deconstruct_keys(keys)
  { value: value, pattern: pattern, operator_loc: operator_loc, location: location }
end

inspect() click to toggle source

def inspect -> String

# File prism/node.rb, line 12918
def inspect
  InspectVisitor.compose(self)
end

operator() click to toggle source

def operator: () -> String

# File prism/node.rb, line 12913
def operator
  operator_loc.slice
end

operator_loc() click to toggle source

attr_reader operator_loc: Location

# File prism/node.rb, line 12906
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 prism/node.rb, line 12936
def type
  :match_required_node
end