class Prism::ClassNode

Represents a class declaration involving the ‘class` keyword.

class Foo end
^^^^^^^^^^^^^

Attributes

body[R]

attr_reader body: Node?

class_keyword_loc[R]

attr_reader class_keyword_loc: Location

constant_path[R]

attr_reader constant_path: Node

end_keyword_loc[R]

attr_reader end_keyword_loc: Location

inheritance_operator_loc[R]

attr_reader inheritance_operator_loc: Location?

locals[R]

attr_reader locals: Array

name[R]

attr_reader name: Symbol

superclass[R]

attr_reader superclass: Node?

Public Class Methods

new(locals, class_keyword_loc, constant_path, inheritance_operator_loc, superclass, body, end_keyword_loc, name, location) click to toggle source

def initialize: (locals: Array, class_keyword_loc: Location, constant_path: Node, inheritance_operator_loc: Location?, superclass: Node?, body: Node?, end_keyword_loc: Location, name: Symbol, location: Location) -> void

# File lib/prism/node.rb, line 3227
def initialize(locals, class_keyword_loc, constant_path, inheritance_operator_loc, superclass, body, end_keyword_loc, name, location)
  @locals = locals
  @class_keyword_loc = class_keyword_loc
  @constant_path = constant_path
  @inheritance_operator_loc = inheritance_operator_loc
  @superclass = superclass
  @body = body
  @end_keyword_loc = end_keyword_loc
  @name = name
  @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 3350
def self.type
  :class_node
end

Public Instance Methods

accept(visitor) click to toggle source

def accept: (visitor: Visitor) -> void

# File lib/prism/node.rb, line 3240
def accept(visitor)
  visitor.visit_class_node(self)
end

child_nodes() click to toggle source

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

# File lib/prism/node.rb, line 3245
def child_nodes
  [constant_path, superclass, body]
end

Also aliased as: deconstruct

class_keyword() click to toggle source

def class_keyword: () -> String

# File lib/prism/node.rb, line 3287
def class_keyword
  class_keyword_loc.slice
end

comment_targets() click to toggle source

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

# File lib/prism/node.rb, line 3259
def comment_targets
  [class_keyword_loc, constant_path, *inheritance_operator_loc, *superclass, *body, end_keyword_loc]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File lib/prism/node.rb, line 3250
def compact_child_nodes
  compact = []
  compact << constant_path
  compact << superclass if superclass
  compact << body if body
  compact
end

copy(**params) click to toggle source

def copy: (**params) -> ClassNode

# File lib/prism/node.rb, line 3264
def copy(**params)
  ClassNode.new(
    params.fetch(:locals) { locals },
    params.fetch(:class_keyword_loc) { class_keyword_loc },
    params.fetch(:constant_path) { constant_path },
    params.fetch(:inheritance_operator_loc) { inheritance_operator_loc },
    params.fetch(:superclass) { superclass },
    params.fetch(:body) { body },
    params.fetch(:end_keyword_loc) { end_keyword_loc },
    params.fetch(:name) { name },
    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 3282
def deconstruct_keys(keys)
  { locals: locals, class_keyword_loc: class_keyword_loc, constant_path: constant_path, inheritance_operator_loc: inheritance_operator_loc, superclass: superclass, body: body, end_keyword_loc: end_keyword_loc, name: name, location: location }
end

end_keyword() click to toggle source

def end_keyword: () -> String

# File lib/prism/node.rb, line 3297
def end_keyword
  end_keyword_loc.slice
end

inheritance_operator() click to toggle source

def inheritance_operator: () -> String?

# File lib/prism/node.rb, line 3292
def inheritance_operator
  inheritance_operator_loc&.slice
end

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

def inspect(inspector: NodeInspector) -> String

# File lib/prism/node.rb, line 3302
def inspect(inspector = NodeInspector.new)
  inspector << inspector.header(self)
  inspector << "├── locals: #{locals.inspect}\n"
  inspector << "├── class_keyword_loc: #{inspector.location(class_keyword_loc)}\n"
  inspector << "├── constant_path:\n"
  inspector << inspector.child_node(constant_path, "│   ")
  inspector << "├── inheritance_operator_loc: #{inspector.location(inheritance_operator_loc)}\n"
  if (superclass = self.superclass).nil?
    inspector << "├── superclass: ∅\n"
  else
    inspector << "├── superclass:\n"
    inspector << superclass.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  if (body = self.body).nil?
    inspector << "├── body: ∅\n"
  else
    inspector << "├── body:\n"
    inspector << body.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  inspector << "├── end_keyword_loc: #{inspector.location(end_keyword_loc)}\n"
  inspector << "└── name: #{name.inspect}\n"
  inspector.to_str
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 3340
def type
  :class_node
end