class Prism::InNode
Represents the use of the ‘in` keyword in a case statement.
case a; in b then c end ^^^^^^^^^^^
Attributes
attr_reader pattern: Node
attr_reader statements: StatementsNode
?
Public Class Methods
def initialize: (pattern: Node
, statements: StatementsNode
?, in_loc
: Location
, then_loc
: Location
?, location: Location
) -> void
# File prism/node.rb, line 8144 def initialize(pattern, statements, in_loc, then_loc, location) @pattern = pattern @statements = statements @in_loc = in_loc @then_loc = then_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 8244 def self.type :in_node end
Public Instance Methods
def accept: (visitor: Visitor
) -> void
# File prism/node.rb, line 8153 def accept(visitor) visitor.visit_in_node(self) end
def child_nodes
: () -> Array[nil | Node]
# File prism/node.rb, line 8158 def child_nodes [pattern, statements] end
def comment_targets
: () -> Array[Node | Location]
# File prism/node.rb, line 8171 def comment_targets [pattern, *statements, in_loc, *then_loc] end
def compact_child_nodes
: () -> Array
# File prism/node.rb, line 8163 def compact_child_nodes compact = [] compact << pattern compact << statements if statements compact end
def copy: (**params) -> InNode
# File prism/node.rb, line 8176 def copy(**params) InNode.new( params.fetch(:pattern) { pattern }, params.fetch(:statements) { statements }, params.fetch(:in_loc) { in_loc }, params.fetch(:then_loc) { then_loc }, params.fetch(:location) { location }, ) end
def in: () -> String
# File prism/node.rb, line 8195 def in in_loc.slice end
def inspect(inspector: NodeInspector) -> String
# File prism/node.rb, line 8205 def inspect(inspector = NodeInspector.new) inspector << inspector.header(self) inspector << "├── pattern:\n" inspector << inspector.child_node(pattern, "│ ") if (statements = self.statements).nil? inspector << "├── statements: ∅\n" else inspector << "├── statements:\n" inspector << statements.inspect(inspector.child_inspector("│ ")).delete_prefix(inspector.prefix) end inspector << "├── in_loc: #{inspector.location(in_loc)}\n" inspector << "└── then_loc: #{inspector.location(then_loc)}\n" inspector.to_str end
def then: () -> String?
# File prism/node.rb, line 8200 def then then_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 8234 def type :in_node end