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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2002-2010, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala.collection
package immutable
import generic._
import mutable.Builder
import scala.util.matching.Regex
import scala.math.ScalaNumber
/**
* @since 2.8
*/
object StringLike {
// just statics for companion class.
private final val LF: Char = 0x0A
private final val FF: Char = 0x0C
private final val CR: Char = 0x0D
private final val SU: Char = 0x1A
}
import StringLike._
/**
* @since 2.8
*/
trait StringLike[+Repr] extends IndexedSeqLike[Char, Repr] with Ordered[String] {
self =>
/** Creates a string builder buffer as builder for this class */
protected[this] def newBuilder: Builder[Char, Repr]
/** Return element at index `n`
* @throws IndexOutofBoundsException if the index is not valid
*/
def apply(n: Int): Char = toString charAt n
def length: Int = toString.length
override def mkString = toString
/** return n times the current string
*/
def * (n: Int): String = {
val buf = new StringBuilder
for (i <- 0 until n) buf append toString
buf.toString
}
override def compare(other: String) = toString compareTo other
private def isLineBreak(c: Char) = c == LF || c == FF
/** <p>
* Strip trailing line end character from this string if it has one.
* A line end character is one of
* </p>
* <ul style="list-style-type: none;">
* <li>LF - line feed (0x0A hex)</li>
* <li>FF - form feed (0x0C hex)</li>
* </ul>
* <p>
* If a line feed character LF is preceded by a carriage return CR
* (0x0D hex), the CR character is also stripped (Windows convention).
* </p>
*/
def stripLineEnd: String = {
val len = toString.length
if (len == 0) toString
else {
val last = apply(len - 1)
if (isLineBreak(last))
toString.substring(0, if (last == LF && len >= 2 && apply(len - 2) == CR) len - 2 else len - 1)
else
toString
}
}
/** <p>
* Return all lines in this string in an iterator, including trailing
* line end characters.
* </p>
* <p>
* The number of strings returned is one greater than the number of line
* end characters in this string. For an empty string, a single empty
* line is returned. A line end character is one of
* </p>
* <ul style="list-style-type: none;">
* <li>LF - line feed (0x0A hex)</li>
* <li>FF - form feed (0x0C hex)</li>
* </ul>
*/
def linesWithSeparators: Iterator[String] = new Iterator[String] {
val str = self.toString
private val len = str.length
private var index = 0
def hasNext: Boolean = index < len
def next(): String = {
if (index >= len) throw new NoSuchElementException("next on empty iterator")
val start = index
while (index < len && !isLineBreak(apply(index))) index += 1
index += 1
str.substring(start, index min len)
}
}
/** Return all lines in this string in an iterator, excluding trailing line
* end characters, i.e. apply <code>.stripLineEnd</code> to all lines
* returned by <code>linesWithSeparators</code>.
*/
def lines: Iterator[String] =
linesWithSeparators map (line => new WrappedString(line).stripLineEnd)
/** Return all lines in this string in an iterator, excluding trailing line
* end characters, i.e. apply <code>.stripLineEnd</code> to all lines
* returned by <code>linesWithSeparators</code>.
*/
def linesIterator: Iterator[String] =
linesWithSeparators map (line => new WrappedString(line).stripLineEnd)
/** Returns this string with first character converted to upper case */
def capitalize: String =
if (toString == null) null
else if (toString.length == 0) ""
else {
val chars = toString.toCharArray
chars(0) = chars(0).toUpper
new String(chars)
}
/** Returns this string with the given <code>prefix</code> stripped. */
def stripPrefix(prefix: String) =
if (toString.startsWith(prefix)) toString.substring(prefix.length)
else toString
/** Returns this string with the given <code>suffix</code> stripped. */
def stripSuffix(suffix: String) =
if (toString.endsWith(suffix)) toString.substring(0, toString.length() - suffix.length)
else toString
/** <p>
* For every line in this string:
* </p>
* <blockquote>
* Strip a leading prefix consisting of blanks or control characters
* followed by <code>marginChar</code> from the line.
* </blockquote>
*/
def stripMargin(marginChar: Char): String = {
val buf = new StringBuilder
for (line <- linesWithSeparators) {
val len = line.length
var index = 0
while (index < len && line.charAt(index) <= ' ') index += 1
buf append
(if (index < len && line.charAt(index) == marginChar) line.substring(index + 1) else line)
}
buf.toString
}
/** <p>
* For every line in this string:
* </p>
* <blockquote>
* Strip a leading prefix consisting of blanks or control characters
* followed by <code>|</code> from the line.
* </blockquote>
*/
def stripMargin: String = stripMargin('|')
private def escape(ch: Char): String = "\\Q" + ch + "\\E"
@throws(classOf[java.util.regex.PatternSyntaxException])
def split(separator: Char): Array[String] = toString.split(escape(separator))
@throws(classOf[java.util.regex.PatternSyntaxException])
def split(separators: Array[Char]): Array[String] = {
val re = separators.foldLeft("[")(_+escape(_)) + "]"
toString.split(re)
}
/** You can follow a string with `.r', turning
* it into a Regex. E.g.
*
* """A\w*""".r is the regular expression for identifiers starting with `A'.
*/
def r: Regex = new Regex(toString)
def toBoolean: Boolean = parseBoolean(toString)
def toByte: Byte = java.lang.Byte.parseByte(toString)
def toShort: Short = java.lang.Short.parseShort(toString)
def toInt: Int = java.lang.Integer.parseInt(toString)
def toLong: Long = java.lang.Long.parseLong(toString)
def toFloat: Float = java.lang.Float.parseFloat(toString)
def toDouble: Double = java.lang.Double.parseDouble(toString)
private def parseBoolean(s: String): Boolean =
if (s != null) s.toLowerCase match {
case "true" => true
case "false" => false
case _ => throw new NumberFormatException("For input string: \""+s+"\"")
}
else
throw new NumberFormatException("For input string: \"null\"")
/* !!! causes crash?
def toArray: Array[Char] = {
val result = new Array[Char](length)
toString.getChars(0, length, result, 0)
result
}
*/
private def unwrapArg(arg: Any): AnyRef = arg match {
case x: ScalaNumber => x.underlying
case x => x.asInstanceOf[AnyRef]
}
/** <p>
* Uses the underlying string as a pattern (in a fashion similar to
* printf in C), and uses the supplied arguments to fill in the
* holes.
* </p>
* <p>
* The interpretation of the formatting patterns is described in
* <a href="" target="contentFrame" class="java/util/Formatter">
* <code>java.util.Formatter</code></a>, with the addition that
* classes deriving from ScalaNumber (such as scala.BigInt and
* scala.BigDecimal) are unwrapped to pass a type which Formatter
* understands.
* </p>
*
* @param args the arguments used to instantiating the pattern.
* @throws java.lang.IllegalArgumentException
*/
def format(args : Any*): String =
java.lang.String.format(toString, args map unwrapArg: _*)
/** <p>
* Like format(args*) but takes an initial Locale parameter
* which influences formatting as in java.lang.String's format.
* </p>
* <p>
* The interpretation of the formatting patterns is described in
* <a href="" target="contentFrame" class="java/util/Formatter">
* <code>java.util.Formatter</code></a>, with the addition that
* classes deriving from ScalaNumber (such as scala.BigInt and
* scala.BigDecimal) are unwrapped to pass a type which Formatter
* understands.
* </p>
*
* @param locale an instance of java.util.Locale
* @param args the arguments used to instantiating the pattern.
* @throws java.lang.IllegalArgumentException
*/
def format(l: java.util.Locale, args: Any*): String =
java.lang.String.format(l, toString, args map unwrapArg: _*)
}
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