class Prism::MatchRequiredNode

Represents the use of the ‘=>` operator.

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

Attributes

operator_loc[R]

attr_reader operator_loc: Location

pattern[R]

attr_reader pattern: Node

value[R]

attr_reader value: Node

Public Class Methods

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

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

# File lib/prism/node.rb, line 11709
def initialize(value, pattern, operator_loc, location)
  @value = value
  @pattern = pattern
  @operator_loc = operator_loc
  @location = location
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 11794
def self.type
  :match_required_node
end

Public Instance Methods

accept(visitor) click to toggle source

def accept: (visitor: Visitor) -> void

# File lib/prism/node.rb, line 11717
def accept(visitor)
  visitor.visit_match_required_node(self)
end

child_nodes() click to toggle source

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

# File lib/prism/node.rb, line 11722
def child_nodes
  [value, pattern]
end

Also aliased as: deconstruct

comment_targets() click to toggle source

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

# File lib/prism/node.rb, line 11732
def comment_targets
  [value, pattern, operator_loc]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File lib/prism/node.rb, line 11727
def compact_child_nodes
  [value, pattern]
end

copy(**params) click to toggle source

def copy: (**params) -> MatchRequiredNode

# File lib/prism/node.rb, line 11737
def copy(**params)
  MatchRequiredNode.new(
    params.fetch(:value) { value },
    params.fetch(:pattern) { pattern },
    params.fetch(:operator_loc) { operator_loc },
    params.fetch(:location) { location },
  )
end

deconstruct()

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

Alias for: child_nodes

deconstruct_keys(keys) click to toggle source

# File lib/prism/node.rb, line 11750
def deconstruct_keys(keys)
  { value: value, pattern: pattern, operator_loc: operator_loc, location: location }
end

inspect(inspector = NodeInspector.new) click to toggle source

def inspect(inspector: NodeInspector) -> String

# File lib/prism/node.rb, line 11760
def inspect(inspector = NodeInspector.new)
  inspector << inspector.header(self)
  inspector << "├── value:\n"
  inspector << inspector.child_node(value, "│   ")
  inspector << "├── pattern:\n"
  inspector << inspector.child_node(pattern, "│   ")
  inspector << "└── operator_loc: #{inspector.location(operator_loc)}\n"
  inspector.to_str
end

operator() click to toggle source

def operator: () -> String

# File lib/prism/node.rb, line 11755
def operator
  operator_loc.slice
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 11784
def type
  :match_required_node
end