regex – 如何在scala中的单词后截断字符串

鉴于以下字符串……

"localhost:9000/one/two/three"

我想在单词二之后截断它并得到

"localhost:9000/one/two"

我已经实现了truncateBefore和truncateAfter方法,如下所示：

def truncateBefore(s: String,p: String) = {
  s.substring(s.indexOf(p) + p.length,s.length)
}

def truncateAfter(s: String,p: String) = {
  s.substring(0,s.indexOf(p) + p.length)
}

这些方法起作用并返回预期结果：

scala> truncateAfter("localhost:9000/one/two/three","three")
res1: String = localhost:9000/one/two

scala> truncateBefore("localhost:9000/one/two/three","three")
res2: String = /three

在scala中有更好的方法吗？最好用正则表达式？

解决方法

在第一个字面之后拆分,没有太多的正则表达式(双关语).

scala> implicit class `split after`(val s: String) {
     | def splitAfter(p: String): (String,String) = {
     |   val r = (Regex quote p).r
     |   r findFirstMatchIn s map (m => (s.substring(0,m.end),m.after.toString)) getorElse (s,"")
     | }}
defined class split$u0020after

scala> "abcfoodeffooghi" splitAfter "foo"
res2: (String,String) = (abcfoo,deffooghi)

scala> "abc*def" splitAfter "*"
res3: (String,String) = (abc*,def)