import Foundation
let pattern = #"(Ulist\d+)(\[\[(?>[^][]|(?2))*]])"#
let regex = try! NSRegularExpression(pattern: pattern)
let testString = #"| item1 | item2 | item3 | Ulist1[[ | item4 | item5 | Ulist2[[ | item6 | item7 ]] | item8 ]] | item9 | list3[[ | item10 | item11 | item12 ]] | item13 | item14"#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let matches = regex.matches(in: testString, range: stringRange)
var result: [[String]] = []
for match in matches {
var groups: [String] = []
for rangeIndex in 1 ..< match.numberOfRanges {
let nsRange = match.range(at: rangeIndex)
guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue }
let string = (testString as NSString).substring(with: nsRange)
groups.append(string)
}
if !groups.isEmpty {
result.append(groups)
}
}
print(result)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression