import Foundation
let pattern = ##"([\s\S]*)(\#)([a-zA_Z0-9]*)(\#)(\s*)(.*)([\s\S]*)"##
let regex = try! NSRegularExpression(pattern: pattern)
let testString = ##"""
1 OPTION 1
2 OPTION 2
3 OPTION 3
4 OPTION 4
5 OPTION 5
6 OPTION 6
7 OPTION 7
8 OPTION 8
9 OPTION 9
10 OPTION 10
100 OPTION 100
#1000# OPTION 1000
[REPLACEALL]([\s\S]*)(\#)([a-zA_Z0-9]*)(\#)(\s*)(.*)([\s\S]*)[WITH]$6
"""##
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"$6"#
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