Regex for filtering out inline comments about nocco HOT 2 CLOSED

I think that I have found a regular expression that will work:

var pattern = @"(?<=^([^""]*""[^""]*"")*[^""']*)(\s*'.*)$";

The fact that C# can only delimit strings with quotes makes this a little harder to read than it is. If we don't have to escape any quotes, it would look like this:

(?<=^([^"]*"[^"]*")*[^"']*)(\s*'.*)$

I'll explain it a little. You should test it too, just to make sure it works.

The end of the regular expression is the obvious part: (\s*'.*)$. It is just matching any whitespace followed by a single quote followed by anything until the end of the line. This represents the comment that we're trying to find.

The beginning of the regular expression basically says that we only find a match if there are an even number of double quotes before (or no double quotes). This makes sure that we are not inside a string when we match the single quote. Let me dive in a little more.

The expression begins with a pattern wrapped in a zero-width positive lookbehind: (?<=. This tells the engine that we only want a match if this pattern exists before everything else. It is zero-width, which means that it won't actually be part of the match. From there, it is pretty simple. It looks for anything but a ", followed by a ", followed by anything but a "", followed by a"` as many times as it can. In other words, it will match anything with two quotes as many times as it can.

Regular expressions are confusing. I hope that this helps. When I get more time, I'll test it some more and then maybe I'll add it into Language.cs. Or, you can do it and send a pull request!

from nocco.

Thanks for your time on this. I'll take a look and see if I can get it working.

from nocco.