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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2002-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala
package reflect.internal.util
/** This object provides utility methods to extract elements
* from Strings.
*
* @author Martin Odersky
* @version 1.0
*/
trait StringOps {
def oempty(xs: String*) = xs filterNot (x => x == null || x == "")
def ojoin(xs: String*): String = oempty(xs: _*) mkString " "
def longestCommonPrefix(xs: List[String]): String = {
if (xs.isEmpty || xs.contains("")) ""
else xs.head.head match {
case ch =>
if (xs.tail forall (_.head == ch)) "" + ch + longestCommonPrefix(xs map (_.tail))
else ""
}
}
def decompose(str: String, sep: Char): List[String] = {
def ws(start: Int): List[String] =
if (start == str.length) List()
else if (str.charAt(start) == sep) ws(start + 1)
else {
val end = str.indexOf(sep, start)
if (end < 0) List(str.substring(start))
else str.substring(start, end) :: ws(end + 1)
}
ws(0)
}
def words(str: String): List[String] = decompose(str, ' ')
def splitWhere(str: String, f: Char => Boolean, doDropIndex: Boolean = false): Option[(String, String)] =
splitAt(str, str indexWhere f, doDropIndex)
def splitAt(str: String, idx: Int, doDropIndex: Boolean = false): Option[(String, String)] =
if (idx == -1) None
else Some((str take idx, str drop (if (doDropIndex) idx + 1 else idx)))
/** Returns a string meaning "n elements".
*/
def countElementsAsString(n: Int, elements: String): String =
n match {
case 0 => "no " + elements + "s"
case 1 => "one " + elements
case 2 => "two " + elements + "s"
case 3 => "three " + elements + "s"
case 4 => "four " + elements + "s"
case _ => "" + n + " " + elements + "s"
}
/** Turns a count into a friendly English description if n<=4.
*/
def countAsString(n: Int): String =
n match {
case 0 => "none"
case 1 => "one"
case 2 => "two"
case 3 => "three"
case 4 => "four"
case _ => "" + n
}
}
object StringOps extends StringOps { }
|
