import Foundation
let pattern = #"([-\d.]+),([-\d.]+),?"#
let regex = try! NSRegularExpression(pattern: pattern)
let testString = #"""
38.313072,-89.863845,38.312675,-89.863586,38.310405,-89.862091,38.310405,-89.862091,38.309913,-89.861976,38.309768,-89.861976,38.309768,-89.861976
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"[$1, $2]\n"#
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