class Prism::HashPatternNode

Represents a hash pattern in pattern matching.

foo => { a: 1, b: 2 }
       ^^^^^^^^^^^^^^

foo => { a: 1, b: 2, **c }
       ^^^^^^^^^^^^^^^^^^^

Attributes

constant[R]

attr_reader constant: Prism::node?

elements[R]

attr_reader elements: Array

rest[R]

attr_reader rest: AssocSplatNode | NoKeywordsParameterNode | nil

Public Class Methods

new(source, constant, elements, rest, opening_loc, closing_loc, location) click to toggle source

def initialize: (Prism::node? constant, Array elements, AssocSplatNode | NoKeywordsParameterNode | nil rest, Location? opening_loc, Location? closing_loc, Location location) -> void

# File lib/prism/node.rb, line 8340
def initialize(source, constant, elements, rest, opening_loc, closing_loc, location)
  @source = source
  @newline = false
  @location = location
  @constant = constant
  @elements = elements
  @rest = rest
  @opening_loc = opening_loc
  @closing_loc = closing_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 lib/prism/node.rb, line 8462
def self.type
  :hash_pattern_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 lib/prism/node.rb, line 8468
def ===(other)
  other.is_a?(HashPatternNode) &&
    (constant === other.constant) &&
    (elements.length == other.elements.length) &&
    elements.zip(other.elements).all? { |left, right| left === right } &&
    (rest === other.rest) &&
    (opening_loc.nil? == other.opening_loc.nil?) &&
    (closing_loc.nil? == other.closing_loc.nil?)
end

accept(visitor) click to toggle source

def accept: (Visitor visitor) -> void

# File lib/prism/node.rb, line 8352
def accept(visitor)
  visitor.visit_hash_pattern_node(self)
end

child_nodes() click to toggle source

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

# File lib/prism/node.rb, line 8357
def child_nodes
  [constant, *elements, rest]
end

Also aliased as: deconstruct

closing() click to toggle source

def closing: () -> String?

# File lib/prism/node.rb, line 8429
def closing
  closing_loc&.slice
end

closing_loc() click to toggle source

attr_reader closing_loc: Location?

# File lib/prism/node.rb, line 8411
def closing_loc
  location = @closing_loc
  case location
  when nil
    nil
  when Location
    location
  else
    @closing_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF)
  end
end

comment_targets() click to toggle source

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

# File lib/prism/node.rb, line 8371
def comment_targets
  [*constant, *elements, *rest, *opening_loc, *closing_loc] #: Array[Prism::node | Location]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File lib/prism/node.rb, line 8362
def compact_child_nodes
  compact = [] #: Array[Prism::node]
  compact << constant if constant
  compact.concat(elements)
  compact << rest if rest
  compact
end

copy(constant: self.constant, elements: self.elements, rest: self.rest, opening_loc: self.opening_loc, closing_loc: self.closing_loc, location: self.location) click to toggle source

def copy: (?constant: Prism::node?, ?elements: Array, ?rest: AssocSplatNode | NoKeywordsParameterNode | nil, ?opening_loc: Location?, ?closing_loc: Location?, ?location: Location) -> HashPatternNode

# File lib/prism/node.rb, line 8376
def copy(constant: self.constant, elements: self.elements, rest: self.rest, opening_loc: self.opening_loc, closing_loc: self.closing_loc, location: self.location)
  HashPatternNode.new(source, constant, elements, rest, opening_loc, closing_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) -> { constant: Prism::node?, elements: Array, rest: AssocSplatNode | NoKeywordsParameterNode | nil, opening_loc: Location?, closing_loc: Location?, location: Location }

# File lib/prism/node.rb, line 8384
def deconstruct_keys(keys)
  { constant: constant, elements: elements, rest: rest, opening_loc: opening_loc, closing_loc: closing_loc, location: location }
end

inspect() click to toggle source

def inspect -> String

# File lib/prism/node.rb, line 8434
def inspect
  InspectVisitor.compose(self)
end

opening() click to toggle source

def opening: () -> String?

# File lib/prism/node.rb, line 8424
def opening
  opening_loc&.slice
end

opening_loc() click to toggle source

attr_reader opening_loc: Location?

# File lib/prism/node.rb, line 8398
def opening_loc
  location = @opening_loc
  case location
  when nil
    nil
  when Location
    location
  else
    @opening_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF)
  end
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 8452
def type
  :hash_pattern_node
end