class Prism::ConstantPathNode
Represents accessing a constant through a path of ‘::` operators.
Foo::Bar ^^^^^^^^
Attributes
The right-hand node of the path. Always a ‘ConstantReadNode` in a valid Ruby syntax tree.
::Foo ^^^ self::Test ^^^^ a.b::C ^
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
def initialize: (Prism::node? parent, ConstantReadNode
| MissingNode
child, Location
delimiter_loc
, Location
location) -> void
# File lib/prism/node.rb, line 4879 def initialize(source, parent, child, delimiter_loc, location) @source = source @newline = false @location = location @parent = parent @child = child @delimiter_loc = delimiter_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 lib/prism/node.rb, line 4996 def self.type :constant_path_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 lib/prism/node.rb, line 5002 def ===(other) other.is_a?(ConstantPathNode) && (parent === other.parent) && (child === other.child) && (delimiter_loc.nil? == other.delimiter_loc.nil?) end
def accept: (Visitor
visitor) -> void
# File lib/prism/node.rb, line 4889 def accept(visitor) visitor.visit_constant_path_node(self) end
def child_nodes
: () -> Array[nil | Node]
# File lib/prism/node.rb, line 4894 def child_nodes [parent, child] end
def comment_targets
: () -> Array[Node | Location]
# File lib/prism/node.rb, line 4907 def comment_targets [*parent, child, delimiter_loc] #: Array[Prism::node | Location] end
def compact_child_nodes
: () -> Array
# File lib/prism/node.rb, line 4899 def compact_child_nodes compact = [] #: Array[Prism::node] compact << parent if parent compact << child compact end
def copy: (?parent: Prism::node?, ?child: ConstantReadNode
| MissingNode
, ?delimiter_loc: Location
, ?location: Location
) -> ConstantPathNode
# File lib/prism/node.rb, line 4912 def copy(parent: self.parent, child: self.child, delimiter_loc: self.delimiter_loc, location: self.location) ConstantPathNode.new(source, parent, child, delimiter_loc, location) end
def deconstruct_keys
: (Array keys) -> { parent: Prism::node?, child: ConstantReadNode
| MissingNode
, delimiter_loc
: Location
, location: Location
}
# File lib/prism/node.rb, line 4920 def deconstruct_keys(keys) { parent: parent, child: child, delimiter_loc: delimiter_loc, location: location } end
def delimiter: () -> String
# File lib/prism/node.rb, line 4963 def delimiter delimiter_loc.slice end
The location of the ‘::` delimiter.
::Foo ^^ One::Two ^^
# File lib/prism/node.rb, line 4956 def delimiter_loc location = @delimiter_loc return location if location.is_a?(Location) @delimiter_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF) end
Returns the full name of this constant path. For example: “Foo::Bar”
# File lib/prism/node_ext.rb, line 162 def full_name full_name_parts.join("::") end
Returns the list of parts for the full name of this constant path. For example: [:Foo, :Bar]
# File lib/prism/node_ext.rb, line 141 def full_name_parts parts = [] #: Array[Symbol] current = self #: node? while current.is_a?(ConstantPathNode) child = current.child if child.is_a?(MissingNode) raise MissingNodesInConstantPathError, "Constant path contains missing nodes. Cannot compute full name" end parts.unshift(child.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
def inspect -> String
# File lib/prism/node.rb, line 4968 def inspect InspectVisitor.compose(self) 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 lib/prism/node.rb, line 4986 def type :constant_path_node end