class Prism::ArrayPatternNode
Represents an array pattern in pattern matching.
foo in 1, 2 ^^^^^^^^^^^ foo in [1, 2] ^^^^^^^^^^^^^ foo in *1 ^^^^^^^^^ foo in Bar[] ^^^^^^^^^^^^ foo in Bar[1, 2, 3] ^^^^^^^^^^^^^^^^^^^
Attributes
attr_reader closing_loc
: Location
?
attr_reader constant: Node
?
attr_reader opening_loc
: Location
?
attr_reader posts: Array
attr_reader requireds: Array
attr_reader rest: Node
?
Public Class Methods
def initialize: (constant: Node
?, requireds: Array, rest: Node
?, posts: Array, opening_loc
: Location
?, closing_loc
: Location
?, location: Location
) -> void
# File prism/node.rb, line 723 def initialize(constant, requireds, rest, posts, opening_loc, closing_loc, location) @constant = constant @requireds = requireds @rest = rest @posts = posts @opening_loc = opening_loc @closing_loc = closing_loc @location = location end
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 835 def self.type :array_pattern_node end
Public Instance Methods
def accept: (visitor: Visitor
) -> void
# File prism/node.rb, line 734 def accept(visitor) visitor.visit_array_pattern_node(self) end
def child_nodes
: () -> Array[nil | Node]
# File prism/node.rb, line 739 def child_nodes [constant, *requireds, rest, *posts] end
def closing: () -> String?
# File prism/node.rb, line 785 def closing closing_loc&.slice end
def comment_targets
: () -> Array[Node | Location]
# File prism/node.rb, line 754 def comment_targets [*constant, *requireds, *rest, *posts, *opening_loc, *closing_loc] end
def compact_child_nodes
: () -> Array
# File prism/node.rb, line 744 def compact_child_nodes compact = [] compact << constant if constant compact.concat(requireds) compact << rest if rest compact.concat(posts) compact end
def copy: (**params) -> ArrayPatternNode
# File prism/node.rb, line 759 def copy(**params) ArrayPatternNode.new( params.fetch(:constant) { constant }, params.fetch(:requireds) { requireds }, params.fetch(:rest) { rest }, params.fetch(:posts) { posts }, params.fetch(:opening_loc) { opening_loc }, params.fetch(:closing_loc) { closing_loc }, params.fetch(:location) { location }, ) end
def deconstruct_keys
: (keys: Array) -> Hash[Symbol, nil | Node
| Array | String | Token
| Array | Location]
# File prism/node.rb, line 775 def deconstruct_keys(keys) { constant: constant, requireds: requireds, rest: rest, posts: posts, opening_loc: opening_loc, closing_loc: closing_loc, location: location } end
def inspect(inspector: NodeInspector) -> String
# File prism/node.rb, line 790 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 << "├── requireds: #{inspector.list("#{inspector.prefix}│ ", requireds)}" 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 << "├── opening_loc: #{inspector.location(opening_loc)}\n" inspector << "└── closing_loc: #{inspector.location(closing_loc)}\n" inspector.to_str end
def opening: () -> String?
# File prism/node.rb, line 780 def opening opening_loc&.slice end
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 825 def type :array_pattern_node end