class Prism::HashPatternNode

Represents a hash pattern in pattern matching.

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

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

Attributes

closing_loc[R]

attr_reader closing_loc: Location?

constant[R]

attr_reader constant: Node?

elements[R]

attr_reader elements: Array

opening_loc[R]

attr_reader opening_loc: Location?

rest[R]

attr_reader rest: Node?

Public Class Methods

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

def initialize: (constant: Node?, elements: Array, rest: Node?, opening_loc: Location?, closing_loc: Location?, location: Location) -> void

# File prism/node.rb, line 7268
def initialize(constant, elements, rest, opening_loc, closing_loc, location)
  @constant = constant
  @elements = elements
  @rest = rest
  @opening_loc = opening_loc
  @closing_loc = closing_loc
  @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 prism/node.rb, line 7376
def self.type
  :hash_pattern_node
end

Public Instance Methods

accept(visitor) click to toggle source

def accept: (visitor: Visitor) -> void

# File prism/node.rb, line 7278
def accept(visitor)
  visitor.visit_hash_pattern_node(self)
end

child_nodes() click to toggle source

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

# File prism/node.rb, line 7283
def child_nodes
  [constant, *elements, rest]
end

Also aliased as: deconstruct

closing() click to toggle source

def closing: () -> String?

# File prism/node.rb, line 7327
def closing
  closing_loc&.slice
end

comment_targets() click to toggle source

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

# File prism/node.rb, line 7297
def comment_targets
  [*constant, *elements, *rest, *opening_loc, *closing_loc]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File prism/node.rb, line 7288
def compact_child_nodes
  compact = []
  compact << constant if constant
  compact.concat(elements)
  compact << rest if rest
  compact
end

copy(**params) click to toggle source

def copy: (**params) -> HashPatternNode

# File prism/node.rb, line 7302
def copy(**params)
  HashPatternNode.new(
    params.fetch(:constant) { constant },
    params.fetch(:elements) { elements },
    params.fetch(:rest) { rest },
    params.fetch(:opening_loc) { opening_loc },
    params.fetch(:closing_loc) { closing_loc },
    params.fetch(:location) { location },
  )
end

deconstruct()

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

Alias for: child_nodes

deconstruct_keys(keys) click to toggle source

# File prism/node.rb, line 7317
def deconstruct_keys(keys)
  { constant: constant, elements: elements, rest: rest, opening_loc: opening_loc, closing_loc: closing_loc, location: location }
end

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

def inspect(inspector: NodeInspector) -> String

# File prism/node.rb, line 7332
def inspect(inspector = NodeInspector.new)
  inspector << inspector.header(self)
  if (constant = self.constant).nil?
    inspector << "├── constant: ∅\n"
  else
    inspector << "├── constant:\n"
    inspector << constant.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  inspector << "├── elements: #{inspector.list("#{inspector.prefix}│   ", elements)}"
  if (rest = self.rest).nil?
    inspector << "├── rest: ∅\n"
  else
    inspector << "├── rest:\n"
    inspector << rest.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  inspector << "├── opening_loc: #{inspector.location(opening_loc)}\n"
  inspector << "└── closing_loc: #{inspector.location(closing_loc)}\n"
  inspector.to_str
end

opening() click to toggle source

def opening: () -> String?

# File prism/node.rb, line 7322
def opening
  opening_loc&.slice
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 7366
def type
  :hash_pattern_node
end