SplitBefore does not match SplitAfter


~~~go
package main

import (
   "fmt"
   "github.com/monstercat/golib/string"
   "strings"
)

func main() {
   out := strings.SplitAfter("hello----world", "---")
   fmt.Printf("%q\n", out)
   out = strutil.SplitBefore("hello----world", "---")
   fmt.Printf("%q\n", out)
}
~~~

result:

~~~
["hello---" "-world"]
["hello" "-" "---world"]
~~~