string - 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:

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.

应该变成:

It is a long established fact that a reader will be distracted by the readable content ...

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

slice 字符串可能会出现问题，因为 slice 适用于字节，而不是 rune 。然而，范围适用于 rune :

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