字符串到UCS-2

时间:2015-05-31 10:56:15

标签: go

我想在Go我的python计划中进行翻译,将unicode字符串转换为UCS-2 HEX字符串。

在python中,它非常简单:

u"Bien joué".encode('utf-16-be').encode('hex')
-> 004200690065006e0020006a006f007500e9

我是Go的初学者,我找到的最简单的方法是:

package main

import (
    "fmt"
    "strings"
)

func main() {
    str := "Bien joué" 
    fmt.Printf("str: %s\n", str)

    ucs2HexArray := []rune(str)
    s := fmt.Sprintf("%U", ucs2HexArray)
    a := strings.Replace(s, "U+", "", -1)
    b := strings.Replace(a, "[", "", -1)
    c := strings.Replace(b, "]", "", -1)
    d := strings.Replace(c, " ", "", -1)
    fmt.Printf("->: %s", d)
}

str: Bien joué
->: 004200690065006E0020006A006F007500E9
Program exited.

我认为它显然效率不高。怎么能改进呢?

谢谢

3 个答案:

答案 0 :(得分:3)

将此转换功能化,然后您可以轻松改进转换算法。例如,

package main

import (
    "fmt"
    "strings"
    "unicode/utf16"
)

func hexUTF16FromString(s string) string {
    hex := fmt.Sprintf("%04x", utf16.Encode([]rune(s)))
    return strings.Replace(hex[1:len(hex)-1], " ", "", -1)
}

func main() {
    str := "Bien joué"
    fmt.Println(str)
    hex := hexUTF16FromString(str)
    fmt.Println(hex)
}

输出:

Bien joué
004200690065006e0020006a006f007500e9

注意:

你说“将unicode字符串转换为UCS-2字符串”,但你的Python示例使用UTF-16:

u"Bien joué".encode('utf-16-be').encode('hex')
  

The Unicode Consortium

     

UTF-16 FAQ

     

Q: What is the difference between UCS-2 and UTF-16?

     

答:UCS-2是过时的术语,指的是Unicode   在代理代码点和之前执行到Unicode 1.1   UTF-16被添加到该标准的2.0版本中。这个词现在应该   要避免。

     

UCS-2没有描述与UTF-16不同的数据格式,因为   两者都使用完全相同的16位代码单元表示。然而,   UCS-2不解释代理代码点,因此不能   习惯于一致地代表补充字符。

     

有时在过去,一个实现被标记为“UCS-2”   表示它不支持补充字符,也不支持   将代理代码点对解释为字符。这样的   实现不会处理字符属性的处理,   补充字符的代码点边界,整理等。

答案 1 :(得分:3)

对于除了简单的短输入之外的任何事情(甚至可能是那时),我会使用golang.org/x/text/encoding/unicode包转换为UTF-16(如@peterSo和@JimB指出,与过时的UCS略有不同 - 2)。

使用此(以及unicode/utf16包)的优势(超过golang.org/x/text/transform)是您获得BOM支持,大或小端,以及您可以编码/解码短字符串或字节,但您也可以将其作为过滤器应用于io.Readerio.Writer,以便在处理数据时转换数据,而不是预先处理所有数据(例如,对于您不需要的大量数据流把它全部记在内存中。)

E.g:

package main

import (
    "bytes"
    "fmt"
    "io"
    "io/ioutil"
    "log"
    "strings"

    "golang.org/x/text/encoding/unicode"
    "golang.org/x/text/transform"
)

const input = "Bien joué"

func main() {
    // Get a `transform.Transformer` for encoding.
    e := unicode.UTF16(unicode.BigEndian, unicode.IgnoreBOM)
    t := e.NewEncoder()
    // For decoding, allows a Byte Order Mark at the start to
    // switch to corresponding Unicode decoding (UTF-8, UTF-16BE, or UTF-16LE)
    // otherwise we use `e` (UTF-16BE without BOM):
    t2 := unicode.BOMOverride(e.NewDecoder())
    _ = t2 // we don't show/use this

    // If you have a string:
    str := input
    outstr, n, err := transform.String(t, str)
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("string:   n=%d, bytes=%02x\n", n, []byte(outstr))

    // If you have a []byte:
    b := []byte(input)
    outbytes, n, err := transform.Bytes(t, b)
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("bytes:    n=%d, bytes=%02x\n", n, outbytes)

    // If you have an io.Reader for the input:
    ir := strings.NewReader(input)
    r := transform.NewReader(ir, t)
    // Now just read from r as you normal would and the encoding will
    // happen as you read, good for large sources to avoid pre-encoding
    // everything. Here we'll just read it all in one go though which negates
    // that benefit (normally avoid ioutil.ReadAll).
    outbytes, err = ioutil.ReadAll(r)
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("reader: len=%d, bytes=%02x\n", len(outbytes), outbytes)

    // If you have an io.Writer for the output:
    var buf bytes.Buffer
    w := transform.NewWriter(&buf, t)
    _, err = fmt.Fprint(w, input) // or io.Copy from an io.Reader, or whatever
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("writer: len=%d, bytes=%02x\n", buf.Len(), buf.Bytes())
}

// Whichever of these you need you could of
// course put in a single simple function. E.g.:

// NewUTF16BEWriter returns a new writer that wraps w
// by transforming the bytes written into UTF-16-BE.
func NewUTF16BEWriter(w io.Writer) io.Writer {
    e := unicode.UTF16(unicode.BigEndian, unicode.IgnoreBOM)
    return transform.NewWriter(w, e.NewEncoder())
}

// ToUTFBE converts UTF8 `b` into UTF-16-BE.
func ToUTF16BE(b []byte) ([]byte, error) {
    e := unicode.UTF16(unicode.BigEndian, unicode.IgnoreBOM)
    out, _, err := transform.Bytes(e.NewEncoder(), b)
    return out, err
}

给出:

string:   n=10, bytes=004200690065006e0020006a006f007500e9
bytes:    n=10, bytes=004200690065006e0020006a006f007500e9
reader: len=18, bytes=004200690065006e0020006a006f007500e9
writer: len=18, bytes=004200690065006e0020006a006f007500e9

答案 2 :(得分:-1)

标准库具有内置的utf16.Encode()https://golang.org/pkg/unicode/utf16/#Encode)功能。