Taking this string as an example:
focus;focus#focus#focus focus
If I want to look for the substring focus, I need this result (matches in bold):
focus;focus#focus#focus focus
This is as far as I got: (?<!#)(focus)(?!#), demo here.
This pattern obviously does not work because is excluding the substrings next to a #, I need those to be included as well.
Programmatically speaking, this is what I need:
if !(prefix == "#" && suffix == "#") {
// Is a match
}