ruby - 将嵌套哈希转换为平面哈希

Question

这道题是this question的逆题.

给定一个嵌套的哈希

{
    :a => {
       :b => {:c => 1, :d => 2},
       :e => 3,
    },
    :f => 4,
}

将它转换成平面散列的最佳方法是什么

{
    [:a, :b, :c] => 1,
    [:a, :b, :d] => 2,
    [:a, :e] => 3,
    [:f] => 4,
}

Answer 1

另一种方式:

def flat_hash(h,f=[],g={})
  return g.update({ f=>h }) unless h.is_a? Hash
  h.each { |k,r| flat_hash(r,f+[k],g) }
  g
end

h = { :a => { :b => { :c => 1,
                      :d => 2 },
              :e => 3 },
      :f => 4 }

flat_hash(h) #=> {[:a, :b, :c]=>1, [:a, :b, :d]=>2, [:a, :e]=>3, [:f]=>4}