如何在golang中椭圆截断文本？

Question

我希望能够干净地剪切大于一定数量字符的段落，而不会在中间剪切一个单词。所以例如这个：一个早已确立的事实是，读者在查看页面布局时会被页面的可读内容分散注意力。使用 Lorem Ipsum 的重点在于它具有或多或少的正态分布字母，而不是使用“这里的内容，这里的内容”，使它看起来像可读的英语。应该变成：读者会被可读的内容分散注意力，这是一个早已确立的事实......这是我想出的功能： func truncateText(s string, max int) string {    if len(s) > max {        r := 0        for i := range s {            r++            if r > max {                return s[:i]            }        }    }    return s}但它只是粗暴地削减了文本。我想知道如何修改（或用更好的解决方案替换它）以椭圆地剪切文本？

Answer 1

切片字符串可能会出现问题，因为切片适用于字节，而不是符文。然而，范围适用于符文：

lastSpaceIx:=-1

len:=0

for i,r:=range str {

  if unicode.IsSpace(r) {

     lastSpaceIx=i

  }

  len++

  if len>=max {

    if lastSpaceIx!=-1 {

        return str[:lastSpaceIx]+"..."

    }

    // If here, string is longer than max, but has no spaces

  }

}

// If here, string is shorter than max

Answer 2

范围是完全没有必要的；就像现在一样，您的整个功能可能只是：

func truncateText(s string, max int) string {

    return s[:max]

}

这太简单了，它甚至不应该是一个函数；但当然它也会切断你说你不想要的单词。因此，您可以：

func truncateText(s string, max int) string {

    if max > len(s) {

        return s

    }

    return s[:strings.LastIndex(s[:max]," ")]

}

或者，如果您想使用多个字符作为单词边界而不仅仅是空格：

func truncateText(s string, max int) string {

    if max > len(s) {

        return s

    }

    return s[:strings.LastIndexAny(s[:max]," .,:;-")]

}

Answer 3

要根据空格等进行拆分，可以使用 regex ：

func splitString(str string) []string {

    re := regexp.MustCompile("[\\s\\n\\t\\r ]+") //split according to \s, \t, \r, \t and whitespace. Edit this regex for other 'conditions'

    split := re.Split(str, -1)

    return split

}

func main() {

    var s = "It is a long\nestablished fact that a reader\nwill\nbe distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English."

    var maxLen = 40

    arr := splitString(s)

    totalLen := 0

    finalStr := ``

    for _, each := range arr {

        if (totalLen + len(each) > maxLen) {

            fmt.Print(strings.TrimSpace(finalStr) + `...`)

            break

        }

        totalLen += len(each)

        finalStr += each + ` `

    }

}

//老2

您可以执行以下操作：将字符串拆分为切片并循环遍历切片，直到字符串的总长度高于最大允许长度。

    var s = "It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English."

    var maxLen = 30

    arr := strings.SplitAfter(s, ` `)

    totalLen := 0

    finalStr := ``

    for _, each := range arr {

        if (totalLen + len(each) > maxLen) {

            fmt.Print(strings.TrimSpace(finalStr) + `...`)

            break

        }

        totalLen += len(each)

        finalStr += each

    }

这是一个早已确立的事实……

//旧的错误答案

您必须使用字符串和切片：

    var s = "It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English."

    newS := s[:30 - 3] 

    newS += `...`

    fmt.Print(newS)

结果 ：It is a long established fa...