Represents a hash key/value pair.
{ a => b }
^^^^^^
The key of the association. This can be any [non-void expression](github.com/ruby/prism/blob/main/docs/parsing_rules.md#non-void-expression).
{ a: b }
^
{ foo => bar }
^^^
{ def a; end => 1 }
^^^^^^^^^^
The value of the association, if present. This can be any [non-void expression](github.com/ruby/prism/blob/main/docs/parsing_rules.md#non-void-expression).
{ foo => bar }
^^^
{ x: 1 }
^
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1054
def initialize(source, key, value, operator_loc, location)
@source = source
@location = location
@key = key
@value = value
@operator_loc = operator_loc
end
def initialize: (Prism::node key, Prism::node value, Location? operator_loc, Location location) -> void
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1166
def self.type
:assoc_node
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 tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1172
def ===(other)
other.is_a?(AssocNode) &&
(key === other.key) &&
(value === other.value) &&
(operator_loc.nil? == other.operator_loc.nil?)
end
Implements case-equality for the node. This is effectively == but without comparing the value of locations. Locations are checked only for presence.
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1063
def accept(visitor)
visitor.visit_assoc_node(self)
end
def accept: (Visitor visitor) -> void
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1068
def child_nodes
[key, value]
end
def child_nodes: () -> Array[nil | Node]
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1078
def comment_targets
[key, value, *operator_loc] #: Array[Prism::node | Location]
end
def comment_targets: () -> Array[Node | Location]
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1073
def compact_child_nodes
[key, value]
end
def compact_child_nodes: () -> Array
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1083
def copy(key: self.key, value: self.value, operator_loc: self.operator_loc, location: self.location)
AssocNode.new(source, key, value, operator_loc, location)
end
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1091
def deconstruct_keys(keys)
{ key: key, value: value, operator_loc: operator_loc, location: location }
end
def deconstruct_keys: (Array keys) -> { key: Prism::node, value: Prism::node, operator_loc: Location?, location: Location }
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1138
def inspect
InspectVisitor.compose(self)
end
def inspect -> String
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1133
def operator
operator_loc&.slice
end
def operator: () -> String?
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1120
def operator_loc
location = @operator_loc
case location
when nil
nil
when Location
location
else
@operator_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF)
end
end
The location of the ‘=>` operator, if present.
{ foo => bar }
^^
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 1156
def type
:assoc_node
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