import Foundation
let pattern = #"^(?!$)M{0,2}(?:M(?=CM(?:XC)?(?:IX)?$))?(?:C(?=M[^CD]*(?:XC)?[^CD]*$))?M?(?:C(?=D[^C]*(?:XC)?[^C]*$))?D?C{0,2}(?:C(?=XC(?:IX)?$))?(?:X(?=C[^X]*(?:IX)?[^X]*$)(?!.*L))?C?(?:X(?=L[^X]*(?:IX)?[^X]*$))?L?X{0,2}(?:X(?=IX$))?(?:I(?=[XV]$))?X?V?I{0,3}$"#
let regex = try! NSRegularExpression(pattern: pattern)
let testString = #"""
I
II
XXIX
XXXVIII
IV
XIV
XXXIX
LXXX
XL
CCCXCIX
DCCCXCIX
CDXC
MMMCMIX
MMMCMXCIX
MMMCM
(MMMCM)CMI
(I)
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
if let firstMatch = regex.firstMatch(in: testString, range: stringRange) {
let result: [String] = (1 ..< firstMatch.numberOfRanges).map { (testString as NSString).substring(with: firstMatch.range(at: $0)) }
print(result)
} else {
print("No matches were found.")
}
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