import Foundation
let pattern = #"\b-(\s+(?:and|to|or)(?:\s+\w+)*\s+\w+(-\w[\w-]*))"#
let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines)
let testString = #"""
But seeing them playing to seven- and eight-year-olds is beautiful
The country was in the uproar of pre- and then post-independence civil war but the mood here is most often joyous
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"\2\1"#
let result = regex.stringByReplacingMatches(in: testString, range: stringRange, withTemplate: substitutionString)
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