问Ruby:基于范围的数据结构中的键查找

EN

class RangedKeyHash < Hash
  def [](key)
    case key
    when 1..4
      super("A")
    when 5..6
      super("B")
    else
      raise KeyError, "#{key} not valid"
    end
  end
end

hash = RangedKeyHash.new
hash["A"] = "value for A"
hash["B"] = "value for B"
hash[2]
# => "value for A"
hash[5]
# => "value for B"
hash[100]
# => KeyError

class RangedHash
  def initialize(hash)
    @hash = hash.to_hash
  end

  def [](key)
    @hash.find do |k, v|
      break v if k.respond_to?(:include?) && k.include?(key) || k == v
    end
  end
end

hash = RangedHash.new(1..4 => 'A', 5..6 => 'B')

hash[2] => "A"    
hash[5] => "B"  
hash[7] => nil