golang 中的字符串转换和 Unicode

Question

我正在阅读 Go Essentials :

String in Go is an immutable sequence of bytes (8-bit byte values) This is different than languages like Python, C#, Java or Swift where strings are Unicode.

我正在玩以下代码:

s := "日本語"
b :=[]byte{0xe6, 0x97, 0xa5, 0xe6, 0x9c, 0xac, 0xe8, 0xaa, 0x9e}
fmt.Println(string(b) == s) // true

for i, runeChar := range b {
    fmt.Printf("byte position %d: %#U\n", i, runeChar)
}

//byte position 0: U+00E6 'æ'
//byte position 1: U+0097
//byte position 2: U+00A5 '¥'
//byte position 3: U+00E6 'æ'
//byte position 4: U+009C
//byte position 5: U+00AC '¬'
//byte position 6: U+00E8 'è'
//byte position 7: U+00AA 'ª'
//byte position 8: U+009E

for i, runeChar := range string(b) {
    fmt.Printf("byte position %d: %#U\n", i, runeChar)
}

//byte position 0: U+65E5 '日'
//byte position 3: U+672C '本'
//byte position 6: U+8A9E '語'

问题:

1. 当转换为字符串时，Golang 从哪里获取用于编码字节数组的 Unicode？ rune 是如何形成的？ Golang编译器在编译过程中是否从文本文件编码中获取Unicode？

2. 将 String 实现为字节数组而不是 Java 中的 utf-16 字符数组有哪些优点和缺点？

Answer 1

您引用的来源不可靠:Go Essentials: Strings .除其他事项外，没有提及 Unicode 代码点或 UTF-8 编码。

---

例如，

package main

import "fmt"

func main() {
    s := "日本語"
    fmt.Printf("Glyph:             %q\n", s)
    fmt.Printf("UTF-8:             [% x]\n", []byte(s))
    fmt.Printf("Unicode codepoint: %U\n", []rune(s))
}

Playground :https://play.golang.org/p/iaYd80Ocitg

输出:

Glyph:             "日本語"
UTF-8:             [e6 97 a5 e6 9c ac e8 aa 9e]
Unicode codepoint: [U+65E5 U+672C U+8A9E]

---

引用资料:

The Go Blog: Strings, bytes, runes and characters in Go

The Go Programming Language Specification

Unicode FAQ: UTF-8, UTF-16, UTF-32 & BOM

The Unicode Consortium