正则表达式过滤掉以“字符串”后缀结尾的单词 - 没有前瞻

Question

我正在尝试提出一个 Ruby 匹配以下字符串的正则表达式：

MAINT: Refactor something
STRY-1: Add something
STRY-2: Update something

但不应匹配以下内容：

MAINT: Refactored something
STRY-1: Added something
STRY-2: Updated something

MAINT: Refactoring something
STRY-3: Adding something
STRY-4: Updating something

基本上，: 之后的第一个单词不应以 ed 或 ing 结尾

我已经使用以下正则表达式 GitLab 提交消息一段时间了。

^(MAINT|(STRY|PRB)-\d+):\s(?:(?!(?:ed|ing)\b)[A-Za-z])+\s([a-zA-Z0-9._\-"].*)

然而，最近他们似乎已经改用不支持前瞻的google/re2。

是否可以重写此正则表达式以便不使用前瞻？

Answer 1

没有正则表达式：

str = "MAINT: Refactor something
STRY-1: Add something
STRY-2: Update something"

p str.lines.none?{|line| line.split[1].end_with?("ed", "ing")}
# => true

Answer 2

str =<<_
MAINT: Refactor something
STRY-1: Added something
MAINT: Refactoring something
Add something
STRY-3: Adding something
STRY-1: Add something
MAINT: Refactored something
Refactor something
STRY-4: Updating something
STRY-9:   Update something
STRY-2: Updated something
_

r = /
    ^                      # Match beginning of line
    (?:                    # Begin non-capture group
      MAINT\:[ ]+Refactor  # Match string
      |                    # or
      STRY-\d+\:[ ]+       # match string
      (?:Add|Update)       # match 'Add' or 'Update'
    )                      # end non-capture group
    [ ]+something          # match one or more spaces followed by 'something'
    $                      # match end of line
    /x                     # free-spacing regex definition modes

str.scan(r)
  #=> ["MAINT: Refactor something\n",
  #    "STRY-1: Add something\n",
  #    "STRY-9:   Update something\n"]

为了匹配正则表达式中的 space，我使用了包含 space ([ ]) 的字符 class。这是必需的，因为 free-spacing 模式删除了不在 class 字符中的 space。按照约定的方式写，正则表达式如下

/^(?:MAINT\: +Refactor|STRY-\d+\: +(?:Add|Update)) +something$/

Answer 3

您正在处理一个必须注意三个结尾的正则表达式：

ed\b
ing\b
ied\b

你必须考虑每个单独点的存在。例如，e[^d]\b 和 [^e]d\b。编写所有这些你将使用这个正则表达式：

^(MAINT|(STRY|PRB)-\d+):\s*(?i:\w*(e[a-ce-z]|[a-df-z]d|i(n[a-fh-z]|[a-mo-z]g|e[a-ce-z]|[a-df-z]d)|[a-hj-z]ng|[a-hj-z][a-df-mo-z][a-cefh-z])|\w)\s([a-zA-Z0-9._\-"].*)

Live demo

正则表达式过滤掉以“字符串”后缀结尾的单词 - 没有前瞻

Regex to filter out word ending with a “string” suffix - without lookahead

ruby

regex

re2

gitlab