# class Prism::LambdaNode

Represents using a lambda literal (not the lambda method call).

    ->(value) { value * 2 }
    ^^^^^^^^^^^^^^^^^^^^^^^

### Attributes

body[R]

attr_reader body: `Node`?

closing_loc[R]

attr_reader `closing_loc`: `Location`

locals[R]

attr_reader locals: Array

locals_body_index[R]

attr_reader `locals_body_index`: `Integer`

opening_loc[R]

attr_reader `opening_loc`: `Location`

operator_loc[R]

attr_reader `operator_loc`: `Location`

parameters[R]

attr_reader parameters: `Node`?

### Public Class Methods

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

def initialize: (locals: Array, `locals_body_index`: `Integer`, `operator_loc`: `Location`, `opening_loc`: `Location`, `closing_loc`: `Location`, parameters: `Node`?, body: `Node`?, location: `Location`) -> void

    # File lib/prism/node.rb, line 10632
    def initialize(locals, locals_body_index, operator_loc, opening_loc, closing_loc, parameters, body, location)
      @locals = locals
      @locals_body_index = locals_body_index
      @operator_loc = operator_loc
      @opening_loc = opening_loc
      @closing_loc = closing_loc
      @parameters = parameters
      @body = body
      @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 10750
    def self.type
      :lambda_node
    end

### Public Instance Methods

accept(visitor) click to toggle source

def accept: (visitor: `Visitor`) -> void

    # File lib/prism/node.rb, line 10644
    def accept(visitor)
      visitor.visit_lambda_node(self)
    end

child_nodes() click to toggle source

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

    # File lib/prism/node.rb, line 10649
    def child_nodes
      [parameters, body]
    end

Also aliased as: deconstruct
closing() click to toggle source

def closing: () -> `String`

    # File lib/prism/node.rb, line 10699
    def closing
      closing_loc.slice
    end

comment_targets() click to toggle source

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

    # File lib/prism/node.rb, line 10662
    def comment_targets
      [operator_loc, opening_loc, closing_loc, *parameters, *body]
    end

compact_child_nodes() click to toggle source

def `compact_child_nodes`: () -> Array

    # File lib/prism/node.rb, line 10654
    def compact_child_nodes
      compact = []
      compact << parameters if parameters
      compact << body if body
      compact
    end

copy(**params) click to toggle source

def copy: (**params) -> `LambdaNode`

    # File lib/prism/node.rb, line 10667
    def copy(**params)
      LambdaNode.new(
        params.fetch(:locals) { locals },
        params.fetch(:locals_body_index) { locals_body_index },
        params.fetch(:operator_loc) { operator_loc },
        params.fetch(:opening_loc) { opening_loc },
        params.fetch(:closing_loc) { closing_loc },
        params.fetch(:parameters) { parameters },
        params.fetch(:body) { body },
        params.fetch(:location) { location },
      )
    end

deconstruct()

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

Alias for: child_nodes
deconstruct_keys(keys) click to toggle source

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

    # File lib/prism/node.rb, line 10684
    def deconstruct_keys(keys)
      { locals: locals, locals_body_index: locals_body_index, operator_loc: operator_loc, opening_loc: opening_loc, closing_loc: closing_loc, parameters: parameters, body: body, location: location }
    end

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

def inspect(inspector: NodeInspector) -> `String`

    # File lib/prism/node.rb, line 10704
    def inspect(inspector = NodeInspector.new)
      inspector << inspector.header(self)
      inspector << "├── locals: #{locals.inspect}\n"
      inspector << "├── locals_body_index: #{locals_body_index.inspect}\n"
      inspector << "├── operator_loc: #{inspector.location(operator_loc)}\n"
      inspector << "├── opening_loc: #{inspector.location(opening_loc)}\n"
      inspector << "├── closing_loc: #{inspector.location(closing_loc)}\n"
      if (parameters = self.parameters).nil?
        inspector << "├── parameters: ∅\n"
      else
        inspector << "├── parameters:\n"
        inspector << parameters.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.to_str
    end

opening() click to toggle source

def opening: () -> `String`

    # File lib/prism/node.rb, line 10694
    def opening
      opening_loc.slice
    end

operator() click to toggle source

def operator: () -> `String`

    # File lib/prism/node.rb, line 10689
    def operator
      operator_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 10740
    def type
      :lambda_node
    end