string+match.swift

extension String {     
     /// Check if a string contains in other string considering a minimum match percentage.
     /// - Parameters:
     ///   - string: String that should be tested.
     ///   - matchPercentage: The minimum match percentage.
     /// - Returns: Boolean indication if the requeriment was matched.
     public func contains(_ string: String, matchPercentage: Float) -> Bool {
         let set1 = Set<String>(self.components(separatedBy: .whitespaces))
         let set2 = Set<String>(string.components(separatedBy: .whitespaces))
         let match: Set<String> = set1.intersection(set2)

         let percentage = Float(match.count) / ((Float(set1.count) + Float(set2.count)) / 2)
         return percentage >= matchPercentage
     }
}