matchesBetweenPairs.swift

extension String {
    
    func matchesBetweenPairs(of char: Character) -> [String] {
        let str = "(?<=\\\(char))[^ ]+(?=\\\(char))"
        let regex = try! NSRegularExpression(pattern: str, options: .caseInsensitive)
        let rng = NSRange(location: 0, length: self.characters.count)
        let matches = regex.matches(in: self, options: [], range: rng)
        return matches.map { (self as NSString).substring(with: $0.range) }
    }
    
}