一个正则表达式来匹配这个或恰好

Question

I am tryign to write a Markdown Parser ontop of the LDT JavaScript plugin, that allows a sort-of real-time parsing. It has basic functions and one of them is a custom parser that uses Regex.

While trying to implement a Markdown "parser", I got stuck on lists. I want to match

- This string
* and that string

Or exactly

1. A string that starts with a number whic must be followed by a period.

So, when creating the parser, all the entries are concationated and separated with a pipe ( | ). The template is: new Regexp("^("+s+")$") .

My current Regex to match unordered lists:

 /[-\*]\s[^\n\r]*\n?/

...but this does also match in the center of a line.

What is the regex to match either - or * prefixed strings, or number prefixed strings, but which must have a period?

Answer 1

Avoiding the discussion if this is the right/wrong way to approach your desired task, you could use two group captures and beginning/end line boundaries . The first group capture will allow you to test what type of list it is if there is a match.

 var strings = [ '- This string', '* and that string', '1. A string that starts with a number which must be followed by a period.', 'Bad string', '-Bad string', '*Bad string', '2 Bad string.' ]; var matchRegExp = /^(\\d\\.|\\*|\\-)\\s(.+)$/; var res = strings.map(function (str) { return { str: str, match: str.match(matchRegExp) }; }); document.write('<pre>' + JSON.stringify(res, null, 4) + '</pre>');