Regular expression flags in procedural cosmetic filters

[Kusresa]

Currently, it looks like the procedural cosmetic filter that can take in regex are not able to take in other trailing flags such as /g /i /m or even within the regex like /(?i)example/.

Can support for these be added? They can improve efficiency of rules that can use them and reduce filter length/number of some filters.

[gorhill]

The syntax is the same a literal javascript regex flags:

example.com##body:has-text(/PRIOR/i)

Only two flags are supported: i and m (support for g is pointless).

I partially checked with some filter lists known to use procedural selectors and I could not find any ambiguity. If ever someone needs to lookup for a string literal like /ad/im, the solution is to use a regular expression to work around flag parsing: /\/ad\/im/.

[jspenguin2017]

Would /ad/im* be parsed as string literal or still RegExp?

[gorhill]

String literal. I don't want special syntax such as wildcards -- that is why regex literals are supported, to take care of when a string literal is not enough.

[jspenguin2017]

So the proper solution to make /ad/im a string literal would be add a trailing wildcard?

[Kusresa]

Only two flags are supported: i and m (support for g is pointless).

Just curious, why is it pointless?

[jspenguin2017]

If it matches it matches, doesn't matter how many times.

[Kusresa]

So am I to understand that the g flag isn't needed because uBO already will find all matches and not just stop after the first match? (please correct me if I'm wrong)

[jspenguin2017]

You only need to match once for the filter to trigger.