class Prism::BlockParametersNode

Represents a block’s parameters declaration.

-> (a, b = 1; local) { }
   ^^^^^^^^^^^^^^^^^

foo do |a, b = 1; local|
       ^^^^^^^^^^^^^^^^^
end

Attributes

closing_loc[R]

attr_reader closing_loc: Location?

locals[R]

attr_reader locals: Array

opening_loc[R]

attr_reader opening_loc: Location?

parameters[R]

attr_reader parameters: ParametersNode?

Public Class Methods

new(parameters, locals, opening_loc, closing_loc, location) click to toggle source

def initialize: (parameters: ParametersNode?, locals: Array, opening_loc: Location?, closing_loc: Location?, location: Location) -> void

# File lib/prism/node.rb, line 1758
def initialize(parameters, locals, opening_loc, closing_loc, location)
  @parameters = parameters
  @locals = locals
  @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 lib/prism/node.rb, line 1857
def self.type
  :block_parameters_node
end

Public Instance Methods

accept(visitor) click to toggle source

def accept: (visitor: Visitor) -> void

# File lib/prism/node.rb, line 1767
def accept(visitor)
  visitor.visit_block_parameters_node(self)
end

child_nodes() click to toggle source

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

# File lib/prism/node.rb, line 1772
def child_nodes
  [parameters, *locals]
end

Also aliased as: deconstruct

closing() click to toggle source

def closing: () -> String?

# File lib/prism/node.rb, line 1814
def closing
  closing_loc&.slice
end

comment_targets() click to toggle source

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

# File lib/prism/node.rb, line 1785
def comment_targets
  [*parameters, *locals, *opening_loc, *closing_loc]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File lib/prism/node.rb, line 1777
def compact_child_nodes
  compact = []
  compact << parameters if parameters
  compact.concat(locals)
  compact
end

copy(**params) click to toggle source

def copy: (**params) -> BlockParametersNode

# File lib/prism/node.rb, line 1790
def copy(**params)
  BlockParametersNode.new(
    params.fetch(:parameters) { parameters },
    params.fetch(:locals) { locals },
    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 lib/prism/node.rb, line 1804
def deconstruct_keys(keys)
  { parameters: parameters, locals: locals, 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 lib/prism/node.rb, line 1819
def inspect(inspector = NodeInspector.new)
  inspector << inspector.header(self)
  if (parameters = self.parameters).nil?
    inspector << "├── parameters: ∅\n"
  else
    inspector << "├── parameters:\n"
    inspector << parameters.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  inspector << "├── locals: #{inspector.list("#{inspector.prefix}│   ", locals)}"
  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 lib/prism/node.rb, line 1809
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 lib/prism/node.rb, line 1847
def type
  :block_parameters_node
end