class RuboCop::NodePattern::Compiler

def compile_union(tokens, cur_node, seq_head) 

def compile_union(tokens, cur_node, seq_head)
  fail_due_to('empty union') if tokens.first == '}'
  with_temp_node(cur_node) do |init, temp_node|
    terms = union_terms(tokens, temp_node, seq_head)
    join_terms(init, terms, ' || ')
  end
end