class Prism::ConstantPathNode

Represents accessing a constant through a path of ‘::` operators.

Foo::Bar
^^^^^^^^

Attributes

name[R]

The name of the constant being accessed. This could be ‘nil` in the event of a syntax error.

parent[R]

The left-hand node of the path, if present. It can be ‘nil` or any [non-void expression](github.com/ruby/prism/blob/main/docs/parsing_rules.md#non-void-expression). It will be `nil` when the constant lookup is at the root of the module tree.

Foo::Bar
^^^

self::Test
^^^^

a.b::C
^^^

Public Class Methods

new(source, parent, name, delimiter_loc, name_loc, location) click to toggle source

def initialize: (Prism::node? parent, Symbol? name, Location delimiter_loc, Location name_loc, Location location) -> void

# File prism/node.rb, line 4878
def initialize(source, parent, name, delimiter_loc, name_loc, location)
  @source = source
  @location = location
  @parent = parent
  @name = name
  @delimiter_loc = delimiter_loc
  @name_loc = name_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 4997
def self.type
  :constant_path_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 5003
def ===(other)
  other.is_a?(ConstantPathNode) &&
    (parent === other.parent) &&
    (name === other.name) &&
    (delimiter_loc.nil? == other.delimiter_loc.nil?) &&
    (name_loc.nil? == other.name_loc.nil?)
end

accept(visitor) click to toggle source

def accept: (Visitor visitor) -> void

# File prism/node.rb, line 4888
def accept(visitor)
  visitor.visit_constant_path_node(self)
end

child() click to toggle source

Previously, we had a child node on this class that contained either a constant read or a missing node. To not cause a breaking change, we continue to supply that API.

# File prism/node_ext.rb, line 181
def child
  deprecated("name", "name_loc")
  name ? ConstantReadNode.new(source, name, name_loc) : MissingNode.new(source, location)
end

child_nodes() click to toggle source

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

# File prism/node.rb, line 4893
def child_nodes
  [parent]
end

Also aliased as: deconstruct

comment_targets() click to toggle source

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

# File prism/node.rb, line 4905
def comment_targets
  [*parent, delimiter_loc, name_loc] #: Array[Prism::node | Location]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File prism/node.rb, line 4898
def compact_child_nodes
  compact = [] #: Array[Prism::node]
  compact << parent if parent
  compact
end

copy(parent: self.parent, name: self.name, delimiter_loc: self.delimiter_loc, name_loc: self.name_loc, location: self.location) click to toggle source

def copy: (?parent: Prism::node?, ?name: Symbol?, ?delimiter_loc: Location, ?name_loc: Location, ?location: Location) -> ConstantPathNode

# File prism/node.rb, line 4910
def copy(parent: self.parent, name: self.name, delimiter_loc: self.delimiter_loc, name_loc: self.name_loc, location: self.location)
  ConstantPathNode.new(source, parent, name, delimiter_loc, name_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) -> { parent: Prism::node?, name: Symbol?, delimiter_loc: Location, name_loc: Location, location: Location }

# File prism/node.rb, line 4918
def deconstruct_keys(keys)
  { parent: parent, name: name, delimiter_loc: delimiter_loc, name_loc: name_loc, location: location }
end

delimiter() click to toggle source

def delimiter: () -> String

# File prism/node.rb, line 4964
def delimiter
  delimiter_loc.slice
end

delimiter_loc() click to toggle source

The location of the ‘::` delimiter.

::Foo
^^

One::Two
   ^^

# File prism/node.rb, line 4944
def delimiter_loc
  location = @delimiter_loc
  return location if location.is_a?(Location)
  @delimiter_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF)
end

full_name() click to toggle source

Returns the full name of this constant path. For example: “Foo::Bar”

# File prism/node_ext.rb, line 174
def full_name
  full_name_parts.join("::")
end

full_name_parts() click to toggle source

Returns the list of parts for the full name of this constant path. For example: [:Foo, :Bar]

# File prism/node_ext.rb, line 152
def full_name_parts
  parts = [] #: Array[Symbol]
  current = self #: node?

  while current.is_a?(ConstantPathNode)
    name = current.name
    if name.nil?
      raise MissingNodesInConstantPathError, "Constant path contains missing nodes. Cannot compute full name"
    end

    parts.unshift(name)
    current = current.parent
  end

  if !current.is_a?(ConstantReadNode) && !current.nil?
    raise DynamicPartsInConstantPathError, "Constant path contains dynamic parts. Cannot compute full name"
  end

  parts.unshift(current&.name || :"")
end

inspect() click to toggle source

def inspect -> String

# File prism/node.rb, line 4969
def inspect
  InspectVisitor.compose(self)
end

name_loc() click to toggle source

The location of the name of the constant.

::Foo
  ^^^

One::Two
     ^^^

# File prism/node.rb, line 4957
def name_loc
  location = @name_loc
  return location if location.is_a?(Location)
  @name_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 4987
def type
  :constant_path_node
end