import Foundation
let pattern = ###"(?<=^# .*⤵(?:\n(?!# ).*)*)\n(^## .*)\n(?!#+ )(.*(?:\n(?!#).*)*)"###
let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines)
let testString = ###"""
# Heading 1 ⤵
## Heading 1.1
Text of Heading 1.1
Text can span over multiple lines
Even more text
## Heading 1.2
Text of Heading 1.2
# Heading 2
## Heading 2.1
Text of Heading 2.1
## Heading 2.2
Text of Heading 2.2
# Heading 3 ⤵
## Heading 3.1
Text of Heading 3.1
## Heading 3.2
Text of Heading 3.2
# Heading 4
"""###
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