NSLinguisticTagger：根据标签类型过滤出指定的令牌

Question

我正在尝试根据标签来过滤掉特定的令牌。 运行代码时，将其作为输出。 我只想检索形容词并将其输出。 是否有捷径可寻？

Hello: NSLinguisticTag(_rawValue: Interjection)
World: NSLinguisticTag(_rawValue: Noun)
this: NSLinguisticTag(_rawValue: Determiner)
is: NSLinguisticTag(_rawValue: Verb)
my: NSLinguisticTag(_rawValue: Determiner)
main: NSLinguisticTag(_rawValue: Adjective)
goal: NSLinguisticTag(_rawValue: Noun)

tokenizeText（inputtedText：“您好，这是我的主要目标，使用这些单词并找出形容词，动词和名词”）

Answer 1

您可以在enumerateTags闭包中简单地检查tag是否为.adjective类型，并且仅在以下情况下才继续：

let sentence = "The yellow cat hunts the little gray mouse around the block"
let options: NSLinguisticTagger.Options = [.omitWhitespace, .omitPunctuation, .joinNames]
let schemes = NSLinguisticTagger.availableTagSchemes(forLanguage: "en")
let tagger = NSLinguisticTagger(tagSchemes: schemes, options: Int(options.rawValue))
tagger.string = sentence
tagger.enumerateTags(in: NSRange(location: 0, length: sentence.count), scheme: .nameTypeOrLexicalClass, options: options) { (tag, tokenRange, _, _) in
    guard tag == .adjective, let adjectiveRange = Range(tokenRange, in: sentence) else { return }
    let adjectiveToken = sentence[adjectiveRange]
    print(adjectiveToken)
}

打印输出：

黄色
小
灰色

编辑

如果要使用多个标签类型的标记，可以将标记存储在字典中，这些标记作为键：

let sentence = "The yellow cat hunts the little gray mouse around the block"
let options: NSLinguisticTagger.Options = [.omitWhitespace, .omitPunctuation, .joinNames]
let schemes = NSLinguisticTagger.availableTagSchemes(forLanguage: "en")
let tagger = NSLinguisticTagger(tagSchemes: schemes, options: Int(options.rawValue))
tagger.string = sentence
var tokens: [NSLinguisticTag: [String]] = [:]
tagger.enumerateTags(in: NSRange(location: 0, length: sentence.count), scheme: .nameTypeOrLexicalClass, options: options) { (tag, tokenRange, _, _) in
    guard let tag = tag, let range = Range(tokenRange, in: sentence) else { return }
    let token = String(sentence[range])
    if tokens[tag] != nil {
        tokens[tag]!.append(token)
    } else {
        tokens[tag] = [token]
    }
}
print(tokens[.adjective])
print(tokens[.noun])

打印出：

可选（[[黄色]，“小”，“灰色”]）
可选（[[“ cat”，“ mouse”，“ block”]）

编辑＃2

如果您希望能够从文本中删除某些标签，则可以编写如下扩展名：

extension NSLinguisticTagger {
    func eliminate(unwantedTags: [NSLinguisticTag], from text: String, options: NSLinguisticTagger.Options) -> String {
        string = text
        var textWithoutUnwantedTags = ""
        enumerateTags(in: NSRange(location: 0, length: text.utf16.count), scheme: .nameTypeOrLexicalClass, options: options) { (tag, tokenRange, _, _) in
            guard
                let tag = tag,
                !unwantedTags.contains(tag),
                let range = Range(tokenRange, in: text)
                else { return }
            let token = String(text[range])
            textWithoutUnwantedTags += " \(token)"
        }

        return textWithoutUnwantedTags.trimmingCharacters(in: .whitespaces)
    }
}

然后，您可以像这样使用它：

let sentence = "The yellow cat hunts the little gray mouse around the block"
let options: NSLinguisticTagger.Options = [.omitWhitespace, .omitPunctuation, .joinNames]
let schemes = NSLinguisticTagger.availableTagSchemes(forLanguage: "en")
let tagger = NSLinguisticTagger(tagSchemes: schemes, options: Int(options.rawValue))

let sentenceWithoutAdjectives = tagger.eliminate(unwantedTags: [.adjective], from: sentence, options: options)
print(sentenceWithoutAdjectives)

打印出：

猫在方块周围搜寻鼠标