mirror of https://github.com/docker/cli.git
63 lines
2.2 KiB
Markdown
63 lines
2.2 KiB
Markdown
# Unicode Text Segmentation for Go
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[](https://godoc.org/github.com/rivo/uniseg)
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[](https://goreportcard.com/report/github.com/rivo/uniseg)
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This Go package implements Unicode Text Segmentation according to [Unicode Standard Annex #29](http://unicode.org/reports/tr29/) (Unicode version 12.0.0).
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At this point, only the determination of grapheme cluster boundaries is implemented.
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## Background
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In Go, [strings are read-only slices of bytes](https://blog.golang.org/strings). They can be turned into Unicode code points using the `for` loop or by casting: `[]rune(str)`. However, multiple code points may be combined into one user-perceived character or what the Unicode specification calls "grapheme cluster". Here are some examples:
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|String|Bytes (UTF-8)|Code points (runes)|Grapheme clusters|
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|Käse|6 bytes: `4b 61 cc 88 73 65`|5 code points: `4b 61 308 73 65`|4 clusters: `[4b],[61 308],[73],[65]`|
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|🏳️🌈|14 bytes: `f0 9f 8f b3 ef b8 8f e2 80 8d f0 9f 8c 88`|4 code points: `1f3f3 fe0f 200d 1f308`|1 cluster: `[1f3f3 fe0f 200d 1f308]`|
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|🇩🇪|8 bytes: `f0 9f 87 a9 f0 9f 87 aa`|2 code points: `1f1e9 1f1ea`|1 cluster: `[1f1e9 1f1ea]`|
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This package provides a tool to iterate over these grapheme clusters. This may be used to determine the number of user-perceived characters, to split strings in their intended places, or to extract individual characters which form a unit.
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## Installation
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```bash
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go get github.com/rivo/uniseg
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```
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## Basic Example
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```go
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package uniseg
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import (
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"fmt"
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"github.com/rivo/uniseg"
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)
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func main() {
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gr := uniseg.NewGraphemes("👍🏼!")
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for gr.Next() {
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fmt.Printf("%x ", gr.Runes())
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}
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// Output: [1f44d 1f3fc] [21]
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}
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```
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## Documentation
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Refer to https://godoc.org/github.com/rivo/uniseg for the package's documentation.
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## Dependencies
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This package does not depend on any packages outside the standard library.
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## Your Feedback
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Add your issue here on GitHub. Feel free to get in touch if you have any questions.
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## Version
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Version tags will be introduced once Golang modules are official. Consider this version 0.1.
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