import Foundation
let pattern = #"(?s)[^\n]*\blittle\b(?:(?!\blittle\b|\bfleece\b).)*fleece[^\n]*(?:\n[^\n]*){4}"#
let regex = try! NSRegularExpression(pattern: pattern)
let testString = #"""
1.Mary had a little lamb,
2.Little lamb, little lamb,
3.Mary had a little lamb,
4.Its fleece was white as snow
5.And everywhere that Mary went,
6.Mary went, Mary went,
7.Everywhere that Mary went
8.The lamb was sure to go
9.It followed her to school one day
10.School one day, school one day
11.It followed her to school one day
12.Which was against the rules.
"""#
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