import Foundation
// WARNING: You included a flag that Swift doesn't support: U
// When this flag is set, it inverts the "greediness" of the quantifiers so that they are not greedy by default, but become greedy if followed by '?'.
// As an alternative, this effect can also be achieved by setting a (?U) modifier setting within the pattern or by a question mark behind a quantifier (e.g. .*?).
let pattern = #"(href|src)="((\/\/)(.+))""#
let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines)
let testString = #"""
<a href="//commons.wikimedia.org/wiki/File:Guido_van_Rossum_OSCON_2006.jpg?uselang=ru" class="image">
<img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/6/66/Guido_van_Rossum_OSCON_2006.jpg/220px-Guido_van_Rossum_OSCON_2006.jpg" decoding="async" width="220" height="330" class="thumbimage" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/66/Guido_van_Rossum_OSCON_2006.jpg/330px-Guido_van_Rossum_OSCON_2006.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/66/Guido_van_Rossum_OSCON_2006.jpg/440px-Guido_van_Rossum_OSCON_2006.jpg 2x" data-file-width="2336" data-file-height="3504">
</a>
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"$1="https://$4""#
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