import Foundation
let pattern = #"MatchesBlock[^\{]+\K(.*})"#
let regex = try! NSRegularExpression(pattern: pattern)
let testString = #"""
"var block = new MatchesBlock('page_competition_1_block_competition_matches_summary_5', 'block_competition_matches_summary', {"page":0,"bookmaker_urls":{"13":[{"link":"http:\/\/www.bet365.com\/home\/?affiliate=365_178981","name":"Bet 365"}]},"block_service_id":"competition_summary_block_competitionmatchessummary","round_id":42011,"outgroup":false,"view":2,"competition_id":13});"
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"$1$2$3"#
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