Hash deep_merge

先写几个方法。

 

class Hash

  def deep_merge(hash)
    target = dup
    hash.keys.each do |key|
      if hash[key].is_a? Hash and self[key].is_a? Hash
        target[key] = target[key].deep_merge(hash[key])
        next
      end
      target[key] = hash[key]
    end
    target
  end

  def deep_merge!(second)
    second.each_pair do |k, v|
      if self[k].is_a?(Hash) and second[k].is_a?(Hash)
        self[k].deep_merge!(second[k])
      else
        self[k] = second[k]
      end
    end
  end

  def deep_merge2(other)
    deep_proc = Proc.new { |k, s, o|
      if s.kind_of?(Hash) && o.kind_of?(Hash)
        next s.merge(o, &deep_proc)
      end
      next o
    }
    merge(other, &deep_proc)
  end

  def deep_merge3(second)
    merger = proc { |key, v1, v2| Hash === v1 && Hash === v2 ? v1.merge(v2, &merger) : v2 }
    self.merge(second, &merger)
  end

  def keep_merge(hash)
    target = dup
    hash.keys.each do |key|
      if hash[key].is_a? Hash and self[key].is_a? Hash
        target[key] = target[key].keep_merge(hash[key])
        next
      end
      target.update(hash) { |key, *values| values.flatten.uniq }
    end
    target
  end

end

 

示例：

 

    h1 = {:a => {:b => :c}}
    h2 = {:a => {:l => :x}}
    m1 = h1.merge(h2)
    m2 = h1.deep_merge(h2)
    m3 = h1.deep_merge2(h2)
    m4 = h1.deep_merge!(h2)
    m5 = h1.deep_merge3(h2)
    p m1   #=> {:a=>{:l=>:x}}
    p m2   #=> {:a=>{:l=>:x, :b=>:c}}
    p m3   # => {:a=>{:l=>:x, :b=>:c}}
    p m4   # => {:a=>{:l=>:x}}
    p m5   # => {:a=>{:l=>:x, :b=>:c}}

    first = {
      :data => {
        :name => {
          :first => 'Sam',
          :middle => 'I',
          :last => 'am'
        }
      }
    }

    second = {
      :data => {
        :name => {
          :middle => 'you',
          :last => 'are'
        }
      }
    }

    p first.deep_merge3(second)  # => {:data=>{:name=>{:first=>"Sam", :last=>"are", :middle=>"you"}}}
    p first.keep_merge(second)   # => {:data=>{:name=>{:first=>"Sam", :last=>["am", "are"], :middle=>["I", "you"]}}}