如何使用REGEX在使用Ruby的范围内找到一组独特的单词？

Question

我希望创建一个符合以下要求的Regex：

( 1)必须充当“和”陈述

( 2)这两个词都应该在一个范围内

( 3)它不计算同一个词中的两个。

到目前为止，我有这个工作REGEX，它满足1和2。

/(word1|word2)(?:\W+\w+){0,3}?\W+(word1|word2)/i

示例Regex：

/(cat|dog)(?:\W+\w+){0,3}?\W+(cat|dog)/i

现在可以工作的字符串

• 那只猫吓到了另一只猫。
• 猫喜欢狗。
• 狗喜欢猫。
• 狗讨厌狗。

我不想要的字符串

• 那只猫吓到了另一只猫。
• 狗讨厌狗。

像“猫吓到了另一只猫”这样的短语。将与REGEX匹配，因为它正在搜索第二组中的任何单词，其中包括cat。不过，我不想让它自己去寻找。我只想找狗。

Answer 1

不如：

/(cat|dog)(?:\W+\w+){0,3}?\W+(?!\1)(cat|dog)/

解释：

The regular expression:

(?-imsx:(cat|dog)(?:\W+\w+){0,3}?\W+(?!\1)(cat|dog))

matches as follows:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  (                        group and capture to \1:
----------------------------------------------------------------------
    cat                      'cat'
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    dog                      'dog'
----------------------------------------------------------------------
  )                        end of \1
----------------------------------------------------------------------
  (?:                      group, but do not capture (between 0 and 3
                           times (matching the least amount
                           possible)):
----------------------------------------------------------------------
    \W+                      non-word characters (all but a-z, A-Z,
                             0-9, _) (1 or more times (matching the
                             most amount possible))
----------------------------------------------------------------------
    \w+                      word characters (a-z, A-Z, 0-9, _) (1 or
                             more times (matching the most amount
                             possible))
----------------------------------------------------------------------
  ){0,3}?                  end of grouping
----------------------------------------------------------------------
  \W+                      non-word characters (all but a-z, A-Z, 0-
                           9, _) (1 or more times (matching the most
                           amount possible))
----------------------------------------------------------------------
  (?!                      look ahead to see if there is not:
----------------------------------------------------------------------
    \1                       what was matched by capture \1
----------------------------------------------------------------------
  )                        end of look-ahead
----------------------------------------------------------------------
  (                        group and capture to \2:
----------------------------------------------------------------------
    cat                      'cat'
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    dog                      'dog'
----------------------------------------------------------------------
  )                        end of \2
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------