ruby - 如何使用 Ruby 以有效的方式从字符串中获取所需的格式化散列？

Question

当字符串以以下格式出现时，我想以特定格式进行散列:

给定的字符串:

str = 'A
A = B
A = B = C
A = B = D
A = E = F
G = H
G = I
G = J'

# 变成这样的哈希(需要哈希模式):

{
  "A" => {
    "B" => {
      "C" => nil,
      "D" => nil
    },
    "E" => {
      "F" => nil
    },
  },
  "G" => {
     "H" => nil,
     "I" => nil,
     "J" => nil
  }
}

我尝试了很多方法，但这是最接近的:

output = Hash.new
line_hash = Hash.new
str.each_line do |line|
  arr = line.split("=")
  e = arr.first.strip
  line_hash[e] = {}
  arr.each_with_index do |ele, i|
    break unless arr[i+1]
    line_hash[ele.strip] = arr[i+1] unless output.keys.include?(ele.strip)
  end
  output[e] = line_hash unless output.keys.include?(e)
end

Answer 1

str = "A\nA = B\nA = B = C\nA = B = D\nA = E = F\nG = H\nG = I\nG = J"

curr = h = {}

str.each_line { |l| 
  l.chomp.split(/\s*=\s*/m).each { |c| 
    curr = curr[c] ||= {}; 
  }
  curr = h 
}

puts h
# => {
#  "A" => {
#    "B" => {
#      "C" => {},
#      "D" => {}
#    },
#    "E" => {
#      "F" => {}
#    }
#  },
#  "G" => {
#    "H" => {},
#    "I" => {},
#    "J" => {}
#  }
# }

为了解决方案的清晰性，我希望你能原谅我在叶子上留下空散列而不是空值。

要使叶子无效:

def leaves_nil! hash
   hash.each { |k,v| v.empty? ? hash[k] = nil : leaves_nil!(hash[k]) }  
end