使用javascript中的正则表达式在markdown中过滤列表标记

Question

I have the following regex: \\^(?:[0-9]|\\-|\\+)[\\s\\S]*?\\n\\n\\gm , which should match only for list markups in markdown. There are two problems remaining, first I get match with --- and second with ++text between++ .

So, my Idea was something like this: \\^(?:[0-9]|\\-{1}?|\\+{1}?)[\\s\\S]*?\\n\\n\\gm to give only a match as return when there exist no repetition of + and - .

But this way is not working.

Check regex101 for details: https://regex101.com/r/Q3rA31/1

To be more specific: in markdown exists several possibilities to create lists, each of them I want to match with regex. Unfortunately symbols like ++ and --- does match too which I want to avoid.

+ Create a list by starting a line with `+`, `-`, or `*`
+ Sub-lists are made by indenting 2 spaces:
  - Marker character change forces new list start:
    * Ac tristique libero volutpat at
    + Facilisis in pretium nisl aliquet
    - Nulla volutpat aliquam velit
+ Very easy!

1. Lorem ipsum dolor sit amet
2. Consectetur adipiscing elit
3. Integer molestie lorem at massa


1. You can use sequential numbers...
1. ...or keep all the numbers as `1.`

57. foo
1. bar

Answer 1

This pattern should do the trick:

^[0-9+-]+[ .][\\s\\S]*?\\n{2}

https://regex101.com/r/Q3rA31/2

I simplified the first part from your example, using a character set instead of alternation. However, the big difference comes after that, where the pattern uses [ .] to match a dot or a space immediately after the list character, which seems to be a requirement in markdown syntax.

Answer 2

A simple way to solve this without changing your original very much is to add a negative lookahead after your - and + regex to make sure they aren't followed by duplicates of themselves:

/^(?:[0-9]|\-(?!\-)|\+(?!\+))[\s\S]*?\n\n/mg

https://regex101.com/r/Q3rA31/3