import Foundation
// WARNING: You included a flag that Swift doesn't support: J
// Wehn this flag is set, it allows duplicated capturing group names.
// By default, Swift captures only the last value matched for a repeated capture group.
// As an alternative, the pattern can be modified to contain one capturing group per group you want to get in the result.
let pattern = ##"""
# https://regex101.com/r/fP1oQ6/2
(?(DEFINE)#
(?<W>\s*)
(?<V>\d+(?:\.\d+)?(?&W))
(?<S>[-+]?)
(?<O>(?&W)[-+*\/](?&W))
(?<E>(?&S)(?:(?&V)|\((?&W)(?&E)(?&W)\))(?:(?&O)(?&E))?)#
)#
((?&E))
"""##
let regex = try! NSRegularExpression(pattern: pattern, options: .allowCommentsAndWhitespace)
let testString = #"(8 - 1 + 3) * 6 - ((3 + 7) * 2)"#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let matches = regex.matches(in: testString, range: stringRange)
var result: [[String]] = []
for match in matches {
var groups: [String] = []
for rangeIndex in 1 ..< match.numberOfRanges {
let nsRange = match.range(at: rangeIndex)
guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue }
let string = (testString as NSString).substring(with: nsRange)
groups.append(string)
}
if !groups.isEmpty {
result.append(groups)
}
}
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