import Foundation
let pattern = #"(?:\s(?:low|high)\s)?(?:\S+\s+and\s)?\S+[ \t]+(?:stress|deficiency|limiting)"#
let regex = try! NSRegularExpression(pattern: pattern)
let testString = #"""
salt and water stress
photo-oxidative stress
salinity and high light stress
low-temperature stress
Cd stress
Cu deficiency
N deficiency
IMI stress
no match:
stress
deficiency
limiting
temperature and water
low
high
water and salt
"""#
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