class Dry::Schema::Macros::Key

def filter(...)
  (filter_schema_dsl[name] || filter_schema_dsl.optional(name)).value(...)
  self
end

def maybe(*args, **opts, &block)
  extract_type_spec(args, nullable: true) do |*predicates, type_spec:, type_rule:|
    append_macro(Macros::Maybe) do |macro|
      macro.call(*predicates, type_spec: type_spec, type_rule: type_rule, **opts, &block)
    end
  end
end

def to_ast
  [:predicate, [:key?, [[:name, name], [:input, Undefined]]]]
end

def to_rule
  if trace.captures.empty?
    super
  else
    [super, trace.to_rule(name)].reduce(operation)
  end
end