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Class: Prism::ParametersNode

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, Node
Instance Chain:
self, Node
Inherits: Prism::Node
Defined in: lib/prism/node.rb,
lib/prism/node_ext.rb

Overview

Represents the list of parameters on a method, block, or lambda definition.

def a(b, c, d)
      ^^^^^^^
end

Class Method Summary

Instance Attribute Summary

Node - Inherited

#location

A Location instance that represents the location of this node in the source.
#newline?

See additional method definition at file lib/prism/node.rb line 16.

Instance Method Summary

Node - Inherited

#pretty_print

Similar to inspect, but respects the current level of indentation given by the pretty print object.
#slice

Slice the location of the node from the source.
#to_dot

Convert this node into a graphviz dot graph string.
#deprecated, #newline!, #set_newline_flag

Constructor Details

.new(requireds, optionals, rest, posts, keywords, keyword_rest, block, location) ⇒ ParametersNode

def initialize: (requireds: Array, optionals: Array, rest: Node?, posts: Array, keywords: Array, keyword_rest: Node?, block: BlockParameterNode?, location: Location) -> void

[ GitHub ] 

  


# File 'lib/prism/node.rb', line 13187



def initialize(requireds, optionals, rest, posts, keywords, keyword_rest, block, location)
  @requireds = requireds
  @optionals = optionals
  @rest = rest
  @posts = posts
  @keywords = keywords
  @keyword_rest = keyword_rest
  @block = block
  @location = location
end


  







Class Method Details



  

    .type  
  



  

    

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


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13300



def self.type
  :parameters_node
end


  







Instance Attribute Details



  

    #block   (readonly)
  



  

    

attr_reader block: BlockParameterNode?


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13184



attr_reader :block


  








  

    #keyword_rest   (readonly)
  



  

    

attr_reader keyword_rest: Node?


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13181



attr_reader :keyword_rest


  








  

    #keywords   (readonly)
  



  

    

attr_reader keywords: Array


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13178



attr_reader :keywords


  








  

    #optionals   (readonly)
  



  

    

attr_reader optionals: Array


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13169



attr_reader :optionals


  








  

    #posts   (readonly)
  



  

    

attr_reader posts: Array


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13175



attr_reader :posts


  








  

    #requireds   (readonly)
  



  

    

attr_reader requireds: Array


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13166



attr_reader :requireds


  








  

    #rest   (readonly)
  



  

    

attr_reader rest: Node?


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13172



attr_reader :rest


  







Instance Method Details



  

    #accept(visitor)  
  



  

    

def accept: (visitor: Visitor) -> void


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13199



def accept(visitor)
  visitor.visit_parameters_node(self)
end


  








  

    #child_nodes  
    Also known as: #deconstruct
  



  

    

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


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13204



def child_nodes
  [*requireds, *optionals, rest, *posts, *keywords, keyword_rest, block]
end


  








  

    #comment_targets  
  



  

    

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


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13222



def comment_targets
  [*requireds, *optionals, *rest, *posts, *keywords, *keyword_rest, *block]
end


  








  

    #compact_child_nodes  
  



  

    

def compact_child_nodes: () -> Array


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13209



def compact_child_nodes
  compact = []
  compact.concat(requireds)
  compact.concat(optionals)
  compact << rest if rest
  compact.concat(posts)
  compact.concat(keywords)
  compact << keyword_rest if keyword_rest
  compact << block if block
  compact
end


  








  

    #copy(**params)  
  



  

    

def copy: (**params) -> ParametersNode


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13227



def copy(**params)
  ParametersNode.new(
    params.fetch(:requireds) { requireds },
    params.fetch(:optionals) { optionals },
    params.fetch(:rest) { rest },
    params.fetch(:posts) { posts },
    params.fetch(:keywords) { keywords },
    params.fetch(:keyword_rest) { keyword_rest },
    params.fetch(:block) { block },
    params.fetch(:location) { location },
  )
end


  








  

    #deconstruct  
  



  

    

Alias for #child_nodes.


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13241



alias deconstruct child_nodes


  








  

    #deconstruct_keys(keys)  
  



  

    

def deconstruct_keys: (keys: Array) -> Hash[Symbol, nil | Node | Array | String | Token | Array | Location]


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13244



def deconstruct_keys(keys)
  { requireds: requireds, optionals: optionals, rest: rest, posts: posts, keywords: keywords, keyword_rest: keyword_rest, block: block, location: location }
end


  








  

    #inspect(inspector = NodeInspector.new)  
  



  

    

def inspect(inspector: NodeInspector) -> String


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13249



def inspect(inspector = NodeInspector.new)
  inspector << inspector.header(self)
  inspector << "├── requireds: #{inspector.list("#{inspector.prefix}│   ", requireds)}"
  inspector << "├── optionals: #{inspector.list("#{inspector.prefix}│   ", optionals)}"
  if (rest = self.rest).nil?
    inspector << "├── rest: ∅\n"
  else
    inspector << "├── rest:\n"
    inspector << rest.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  inspector << "├── posts: #{inspector.list("#{inspector.prefix}│   ", posts)}"
  inspector << "├── keywords: #{inspector.list("#{inspector.prefix}│   ", keywords)}"
  if (keyword_rest = self.keyword_rest).nil?
    inspector << "├── keyword_rest: ∅\n"
  else
    inspector << "├── keyword_rest:\n"
    inspector << keyword_rest.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  if (block = self.block).nil?
    inspector << "└── block: ∅\n"
  else
    inspector << "└── block:\n"
    inspector << block.inspect(inspector.child_inspector("    ")).delete_prefix(inspector.prefix)
  end
  inspector.to_str
end


  








  

    #signature  
  



  

    

Mirrors the Method#parameters method.


  



  [ GitHub ]


  

  


# File 'lib/prism/node_ext.rb', line 238



def signature
  names = [] #: Array[[Symbol, Symbol] | [Symbol]]

  requireds.each do |param|
    names << (param.is_a?(MultiTargetNode) ? [:req] : [:req, param.name])
  end

  optionals.each { |param| names << [:opt, param.name] }

  if rest && rest.is_a?(RestParameterNode)
    names << [:rest, rest.name || :*]
  end

  posts.each do |param|
    if param.is_a?(MultiTargetNode)
      names << [:req]
    elsif param.is_a?(NoKeywordsParameterNode)
      # Invalid syntax, e.g. "def f(**nil, ...)" moves the NoKeywordsParameterNode to posts
      raise "Invalid syntax"
    else
      names << [:req, param.name]
    end
  end

  # Regardless of the order in which the keywords were defined, the required
  # keywords always come first followed by the optional keywords.
  keyopt = [] #: Array[OptionalKeywordParameterNode]
  keywords.each do |param|
    if param.is_a?(OptionalKeywordParameterNode)
      keyopt << param
    else
      names << [:keyreq, param.name]
    end
  end

  keyopt.each { |param| names << [:key, param.name] }

  case keyword_rest
  when ForwardingParameterNode
    names.concat([[:rest, :*], [:keyrest, :**], [:block, :&]])
  when KeywordRestParameterNode
    names << [:keyrest, keyword_rest.name || :**]
  when NoKeywordsParameterNode
    names << [:nokey]
  end

  names << [:block, block.name || :&] if block
  names
end


  








  

    #type  
  



  

    

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


  



  [ GitHub ]


  

  


# File 'lib/prism/node.rb', line 13290



def type
  :parameters_node
end