ruby - 将字符串拆分成 block (不同大小)而不打断单词

Question

我正在尝试创建一个方法，给定一个字符串，返回三个字符串:title、description1、description2

这是我发现的一个相关问题:Split a string into chunks of specified size without breaking words - 但我的 block 大小不同。

标题最多需要 25 个字符。

Description1 最多需要 35 个字符。

Description2 最多需要 35 个字符。

问题是:

我怎样才能拆分一个字符串，以便它最多创建三个实体(注意:如果该字符串只适合第一个没问题的实体，我不需要返回三个实体)，其中第一个实体最多有 25 个字符，另外两个最多有 35 个字符。使该方法足够聪明以考虑单词(可能还有标点符号)，这样它就不会返回剪切结果。

我做了以下事情:

def split_text_to_entities(big_string)
  title = big_string(0..24)
  description1 = big_string(25..59)
  description2 = big_string(60..94)
end

但这种方法的问题在于，如果输入是“从我们的商店购买我们的新品牌鞋子。镇上最好的折扣，首次购买可享受 40% 的折扣。”，结果将是:

title = "Buy our new brand shoes f"
description1 = "rom our store. Best discounts in to"
description2 = "wn and 40% off for first purchase."

理想情况下，他们应该是:

title = "Buy our new brand shoes"
description1 = "from our store. Best discounts in"
description2 = "town and 40% off for first"

因此，考虑到单词，尝试按字符大小拆分。

Answer 1

为了涵盖所有基础，我将执行以下操作。

代码

def divide_text(str, max_chars)
  max_chars.map do |n|
    str.lstrip!
    s = str[/^.{,#{n}}(?=\b)/] || ''
    str = str[s.size..-1]
    s
  end
end

(?=\b) 是匹配分词符的(零宽度)正向先行。

示例

max_nbr_chars = [25,35,35]

str = "Buy our new brand shoes from our store. Best discounts in " +
      "town and 40% off for first purchase."    
divide_text(str, max_nbr_chars)
  #=> ["Buy our new brand shoes",
  #    "from our store. Best discounts in",
  #    "town and 40% off for first"]

str = "Buy our new brand shoes from our store."
divide_text(str, max_nbr_chars)
  #=> ["Buy our new brand shoes", "from our store.", ""]

str = "Buy our new"
divide_text(str, max_nbr_chars)
  #=> ["Buy our new", "", ""]

str = ""
divide_text(str, max_nbr_chars)
  #=> ["", "", ""]

str = "Buyournewbrandshoesfromourstore."
divide_text(str, max_nbr_chars)
  #=> ["", "Buyournewbrandshoesfromourstore.", ""]

str = "Buyournewbrandshoesfromourstoreandshoesfromourstore."
divide_text(str, max_nbr_chars)
  #=> ["", "", ""]

请注意，如果正则表达式中省略了 ^:

str = "Buyournewbrandshoesfromourstore."
divide_text(str, max_nbr_chars)
  #=> ["ewbrandshoesfromourstore.", "rstore.", ""]