import Foundation
let pattern = #"(\s+)((?<=\s)[a-z]|^[a-z]).*?([A-Z]?(?<=[a-zA-Z0-9])[a-zA-Z0-9]+)"#
let regex = try! NSRegularExpression(pattern: pattern)
let testString = #"""
do we have a Hashtag
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"$2$3"#
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