Splitting string on dots but not on dots within round brackets

Question

I would like to achieve the above but didn't manage it.

I already tried the regex "\.(?![^(]*\))" but it does not work so far.

I want to split the string "replace(<<accountname>>.right(4), Saturn).invert()" like this:

replace(<<accountname>>.right(4), Saturn)
invert()

Answer 1

You can use a matching approach, i.e. match any one or more occurrences of a string between balanced parentheses or any char other than a .:

var output = Regex.Matches(text, @"(?:\((?>[^()]+|(?<o>)\(|(?<-o>)\))*\)|[^.])+")
    .Cast<Match>()
    .Select(x => x.Value)
    .ToList();

See the .NET regex demo. Details:

• (?: - start of a "container" non-capturing group:
  • \( - a ( char
  • (?>[^()]+|(?<o>)\(|(?<-o>)\))* - zero or more occurrences (backtracking into the pattern is disabled since the (?>...) is an atomic group, this way the pattern is efficient) of
    • [^()]+| - one or more chars other than a ( and ), or
    • (?<o>)\(| - a ( char, and a value is pushed on to Group "o" capture stack, or
    • (?<-o>)\) - a ) char, and a value is popped off the Group "o" capture stack
  • \) - a ) char
• | - or
  • [^.] - any char other than a . char
• )+ - end of the group, repeat one or more times.