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# enumerateTags(in:unit:scheme:options:using:)

Enumerates a block over the tagger’s string, given a range, token unit, and tag scheme.

```
@nonobjc func enumerateTags(in range: Range<String.Index>, unit: NLTokenUnit, scheme: NLTagScheme, options: NLTagger.Options = [], using block: (NLTag?, Range<String.Index>) -> Bool)
```

## Parameters

`range`

The range of the string you want the tagger to analyze.

`unit`

The linguistic unit of scale you’re interested in, such as [`NLTokenUnit.word`](/documentation/NaturalLanguage/NLTokenUnit/word), [`NLTokenUnit.sentence`](/documentation/NaturalLanguage/NLTokenUnit/sentence), [`NLTokenUnit.paragraph`](/documentation/NaturalLanguage/NLTokenUnit/paragraph), or [`NLTokenUnit.document`](/documentation/NaturalLanguage/NLTokenUnit/document).

`scheme`

The tag scheme the tagger uses to tag the string, such as [`language`](/documentation/NaturalLanguage/NLTagScheme/language) or [`script`](/documentation/NaturalLanguage/NLTagScheme/script). This scheme determines which types of [`NLTag`](/documentation/NaturalLanguage/NLTag) the method passes to your block. For other tag schemes, see [`NLTagScheme`](/documentation/NaturalLanguage/NLTagScheme).

`options`

The set of linguistic tagger options to use, such as [`omitWhitespace`](/documentation/NaturalLanguage/NLTagger/Options/omitWhitespace). For all available options, see [`NLTagger.Options`](/documentation/NaturalLanguage/NLTagger/Options).

`block`

The block this method uses to iterate over the tagger’s [`string`](/documentation/NaturalLanguage/NLTagger/string) property. The block has the following parameters:

- tag: The tag of the token.
- tokenRange: The range of the token.
- stop: A reference to a Boolean value. The block can set the value to `true` to stop further processing of the set. The `stop` argument is an out-only argument. You should only ever set this Boolean to `true` within the block.

## Discussion

Use this method to iterate your block over the given range of a string. The method divides up the string with the given [`NLTokenUnit`](/documentation/NaturalLanguage/NLTokenUnit) and [`NLTagScheme`](/documentation/NaturalLanguage/NLTagScheme) and then calls your block. For example, use the [`lexicalClass`](/documentation/NaturalLanguage/NLTagScheme/lexicalClass) tag scheme to identify which tokens are parts of speech, types of whitespace, or types of punctuation. Use the [`lemma`](/documentation/NaturalLanguage/NLTagScheme/lemma) tag scheme to identify the stem form of each word token, if known.

> Important:
> This method enumerates over the ranges of all tokens that intersect the specified range.

---

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