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

def a(b, c, d)
      ^^^^^^^
end
Attributes
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attr_reader requireds: Array[RequiredParameterNode | MultiTargetNode]

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attr_reader optionals: Array

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attr_reader rest: RestParameterNode | ImplicitRestNode | nil

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attr_reader posts: Array[RequiredParameterNode | MultiTargetNode | KeywordRestParameterNode | NoKeywordsParameterNode | ForwardingParameterNode]

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attr_reader keywords: Array[RequiredKeywordParameterNode | OptionalKeywordParameterNode]

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attr_reader block: BlockParameterNode?

Class Methods

def initialize: (Array[RequiredParameterNode | MultiTargetNode] requireds, Array optionals, RestParameterNode | ImplicitRestNode | nil rest, Array[RequiredParameterNode | MultiTargetNode | KeywordRestParameterNode | NoKeywordsParameterNode | ForwardingParameterNode] posts, Array[RequiredKeywordParameterNode | OptionalKeywordParameterNode] keywords, KeywordRestParameterNode | ForwardingParameterNode | NoKeywordsParameterNode | nil keyword_rest, BlockParameterNode? block, Location location) -> void

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

Instance Methods

Implements case-equality for the node. This is effectively == but without comparing the value of locations. Locations are checked only for presence.

def accept: (Visitor visitor) -> void

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

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

def copy: (?requireds: Array[RequiredParameterNode | MultiTargetNode], ?optionals: Array, ?rest: RestParameterNode | ImplicitRestNode | nil, ?posts: Array[RequiredParameterNode | MultiTargetNode | KeywordRestParameterNode | NoKeywordsParameterNode | ForwardingParameterNode], ?keywords: Array[RequiredKeywordParameterNode | OptionalKeywordParameterNode], ?keyword_rest: KeywordRestParameterNode | ForwardingParameterNode | NoKeywordsParameterNode | nil, ?block: BlockParameterNode?, ?location: Location) -> ParametersNode

An alias for child_nodes

def deconstruct_keys: (Array keys) -> { requireds: Array[RequiredParameterNode | MultiTargetNode], optionals: Array, rest: RestParameterNode | ImplicitRestNode | nil, posts: Array[RequiredParameterNode | MultiTargetNode | KeywordRestParameterNode | NoKeywordsParameterNode | ForwardingParameterNode], keywords: Array[RequiredKeywordParameterNode | OptionalKeywordParameterNode], keyword_rest: KeywordRestParameterNode | ForwardingParameterNode | NoKeywordsParameterNode | nil, block: BlockParameterNode?, location: Location }

def inspect -> String

Mirrors the Method#parameters method.

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