swift nspredicate example

swift-nspredicate-example.swift

func search(words: [String]?) -> [Codepoint] {
    guard let searchTerms = words else {
        print("failed to unpack words")
        return []
    }
    
    var predicates : [NSPredicate] = [NSPredicate]()
    for term in searchTerms {
        let codePredicate = NSPredicate(format: "(%@ IN[cd] code)", term)
        let typePredicate = NSPredicate(format: "(%@ IN[cd] type)", term)
        let characterPredicate = NSPredicate(format: "(%@ IN[cd] character)", term)
        let fullPredicate = NSCompoundPredicate(orPredicateWithSubpredicates: [codePredicate, typePredicate, characterPredicate])
        predicates.append(fullPredicate)
    }
    
    let fullPredicates = NSCompoundPredicate(andPredicateWithSubpredicates: predicates)
    
    let filteredArray = self.unicodeArray.filter { 
        fullPredicates.evaluateWithObject($0) 
    }
    return filteredArray
}