IOS/Objective-C：用于识别命名实体的 NSLinguisticTagger

Posted 2023-04-17

【中文标题】IOS/Objective-C：用于识别命名实体的 NSLinguisticTagger

【英文标题】：IOS/Objective-C: NSLinguisticTagger for Recognizing Named Entities

【发布时间】：2019-02-16 07:59:40

【问题描述】：

Apple 提供了一个用于在 Swift 中使用标记器来识别命名实体的方法，但不适用于 Objective-C。

这是他们提供的 Swift 示例：

let text = "The American Red Cross was established in Washington, D.C., by Clara Barton."
let tagger = NSLinguisticTagger(tagSchemes: [.nameType], options: 0)
tagger.string = text
let range = NSRange(location:0, length: text.utf16.count)
let options: NSLinguisticTagger.Options = [.omitPunctuation, .omitWhitespace, .joinNames]
let tags: [NSLinguisticTag] = [.personalName, .placeName, .organizationName]
tagger.enumerateTags(in: range, unit: .word, scheme: .nameType, options: options)  tag, tokenRange, stop in
    if let tag = tag, tags.contains(tag) 
        let name = (text as NSString).substring(with: tokenRange)
        print("\(name): \(tag)")
    

我已经用help from here 翻译它，但我不知道如何指定标签，例如[.personalName, .placeName, .organizationName]：这只是您列举的标签类型数组吗？

NSLinguisticTagger *tagger = [[NSLinguisticTagger alloc]
                              initWithTagSchemes:[NSArray arrayWithObjects:NSLinguisticTagSchemeNameType, nil]
                              options:(NSLinguisticTaggerOmitWhitespace | NSLinguisticTaggerOmitPunctuation | NSLinguisticTaggerJoinNames)];
[tagger setString:text];

[tagger enumerateTagsInRange:NSMakeRange(0, [text length])
                      scheme:NSLinguisticTagSchemeNameType
                     options:(NSLinguisticTaggerOmitWhitespace | NSLinguisticTaggerOmitPunctuation| NSLinguisticTaggerJoinNames)
                  usingBlock:^(NSString *tag, NSRange tokenRange, NSRange sentenceRange, BOOL *stop) 
                      NSString *token = [text substringWithRange:tokenRange];
                      NSString *name =[tagger tagAtIndex:tokenRange.location scheme:NSLinguisticTagSchemeNameType tokenRange:NULL sentenceRange:NULL];

                      if (name == nil) 
                          name = token;
                      

                      NSLog(@"tagger results:%@, %@", token, name);
                  ];

感谢任何关于如何在 Objective-C 中指定标签的建议。

【问题讨论】：

NSArray *tags = [NSLinguisticTagPersonalName, ...]... if (tag && [tags contains:tag]) NSString *name = [text substringWithRange:tokenRange]; NSLog("%@: %@", name, tag);?

好吧，我猜标签只是一个用来比较的数组，而不是你可以放入标签器的过滤器。

我不知道那个 API，但那似乎是 Swift 代码的作用。

【参考方案1】：

原始 Swift 代码：

let text = "The American Red Cross was established in Washington, D.C., by Clara Barton."
let tagger = NSLinguisticTagger(tagSchemes: [.nameType], options: 0)
tagger.string = text
let range = NSRange(location:0, length: text.utf16.count)
let options: NSLinguisticTagger.Options = [.omitPunctuation, .omitWhitespace, .joinNames]
let tags: [NSLinguisticTag] = [.personalName, .placeName, .organizationName]
tagger.enumerateTags(in: range, unit: .word, scheme: .nameType, options: options)  tag, tokenRange, stop in
    if let tag = tag, tags.contains(tag) 
        let name = (text as NSString).substring(with: tokenRange)
        print("\(name): \(tag)")
    

输出：

American Red Cross: NSLinguisticTag(_rawValue: OrganizationName)
Washington: NSLinguisticTag(_rawValue: PlaceName)
Clara Barton: NSLinguisticTag(_rawValue: PersonalName)

Objective-C 版本：

NSString* text = @"The American Red Cross was established in Washington, D.C., by Clara Barton.";
NSLinguisticTagger* tagger = [[NSLinguisticTagger alloc] initWithTagSchemes:@[NSLinguisticTagSchemeNameType] options:0];
tagger.string = text;
NSRange range = NSMakeRange(0, text.length);
NSLinguisticTaggerOptions options = NSLinguisticTaggerOmitPunctuation | NSLinguisticTaggerOmitWhitespace | NSLinguisticTaggerJoinNames;
NSArray* tags = @[NSLinguisticTagPersonalName, NSLinguisticTagPlaceName, NSLinguisticTagOrganizationName];
[tagger enumerateTagsInRange:range unit:NSLinguisticTaggerUnitWord scheme:NSLinguisticTagSchemeNameType options:options usingBlock:^(NSLinguisticTag  _Nullable tag, NSRange tokenRange, BOOL * _Nonnull stop) 
    if ([tags containsObject:tag]) 
        NSString* name = [text substringWithRange:tokenRange];
        NSLog(@"%@: %@", name, tag);
    
];

输出：

2018-09-12 09:51:00.323378-0700 App[2408:109005] American Red Cross: OrganizationName
2018-09-12 09:51:00.323755-0700 App[2408:109005] Washington: PlaceName
2018-09-12 09:51:00.323901-0700 App[2408:109005] Clara Barton: PersonalName