class Prism::LocalVariableWriteNode

Represents writing to a local variable.

foo = 1
^^^^^^^

Attributes

depth[R]

The number of semantic scopes we have to traverse to find the declaration of this variable.

foo = 1         # depth 0

tap { foo = 1 } # depth 1

The specific rules for calculating the depth may differ from individual Ruby implementations, as they are not specified by the language. For more information, see [the Prism documentation](github.com/ruby/prism/blob/main/docs/local_variable_depth.md).

name[R]

The name of the local variable, which is an [identifier](github.com/ruby/prism/blob/main/docs/parsing_rules.md#identifiers).

foo = :bar # name `:foo`

abc = 123  # name `:abc`

value[R]

The value to write to the local variable. It can be any [non-void expression](github.com/ruby/prism/blob/main/docs/parsing_rules.md#non-void-expression).

foo = :bar
      ^^^^

abc = 1234
      ^^^^

Note that since the name of a local variable is known before the value is parsed, it is valid for a local variable to appear within the value of its own write.

foo = foo

Public Class Methods

new(source, name, depth, name_loc, value, operator_loc, location) click to toggle source

def initialize: (Symbol name, Integer depth, Location name_loc, Prism::node value, Location operator_loc, Location location) -> void

# File prism/node.rb, line 12410
def initialize(source, name, depth, name_loc, value, operator_loc, location)
  @source = source
  @location = location
  @name = name
  @depth = depth
  @name_loc = name_loc
  @value = value
  @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 12536
def self.type
  :local_variable_write_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 12542
def ===(other)
  other.is_a?(LocalVariableWriteNode) &&
    (name === other.name) &&
    (depth === other.depth) &&
    (name_loc.nil? == other.name_loc.nil?) &&
    (value === other.value) &&
    (operator_loc.nil? == other.operator_loc.nil?)
end

accept(visitor) click to toggle source

def accept: (Visitor visitor) -> void

# File prism/node.rb, line 12421
def accept(visitor)
  visitor.visit_local_variable_write_node(self)
end

child_nodes() click to toggle source

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

# File prism/node.rb, line 12426
def child_nodes
  [value]
end

Also aliased as: deconstruct

comment_targets() click to toggle source

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

# File prism/node.rb, line 12436
def comment_targets
  [name_loc, value, operator_loc] #: Array[Prism::node | Location]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File prism/node.rb, line 12431
def compact_child_nodes
  [value]
end

copy(name: self.name, depth: self.depth, name_loc: self.name_loc, value: self.value, operator_loc: self.operator_loc, location: self.location) click to toggle source

def copy: (?name: Symbol, ?depth: Integer, ?name_loc: Location, ?value: Prism::node, ?operator_loc: Location, ?location: Location) -> LocalVariableWriteNode

# File prism/node.rb, line 12441
def copy(name: self.name, depth: self.depth, name_loc: self.name_loc, value: self.value, operator_loc: self.operator_loc, location: self.location)
  LocalVariableWriteNode.new(source, name, depth, name_loc, value, 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) -> { name: Symbol, depth: Integer, name_loc: Location, value: Prism::node, operator_loc: Location, location: Location }

# File prism/node.rb, line 12449
def deconstruct_keys(keys)
  { name: name, depth: depth, name_loc: name_loc, value: value, operator_loc: operator_loc, location: location }
end

inspect() click to toggle source

def inspect -> String

# File prism/node.rb, line 12508
def inspect
  InspectVisitor.compose(self)
end

name_loc() click to toggle source

The location of the variable name.

foo = :bar
^^^

# File prism/node.rb, line 12473
def name_loc
  location = @name_loc
  return location if location.is_a?(Location)
  @name_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF)
end

operator() click to toggle source

def operator: () -> String

# File prism/node.rb, line 12503
def operator
  operator_loc.slice
end

operator_loc() click to toggle source

The location of the ‘=` operator.

x = :y
  ^

# File prism/node.rb, line 12496
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 12526
def type
  :local_variable_write_node
end