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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2007, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala.collection.immutable
import Predef.Pair
/** This class implements immutable maps with exactly three entries
* @author Martin Oderskty
* @version 1.0, 019/01/2007
*/
@serializable
class Map3[A, +B](key1: A, value1: B, key2: A, value2: B, key3: A, value3: B) extends Map[A, B] {
def size = 3
def get(key: A): Option[B] =
if (key == key1) Some(value1)
else if (key == key2) Some(value2)
else if (key == key3) Some(value3)
else None
def elements = Iterator.fromValues(
(key1, value1), (key2, value2), (key3, value3))
def empty[C]: Map[A, C] = new EmptyMap[A, C]
def update [B1 >: B](key: A, value: B1): Map[A, B1] =
if (key == key1) new Map3(key1, value, key2, value2, key3, value3)
else if (key == key2) new Map3(key1, value1, key2, value, key3, value3)
else if (key == key3) new Map3(key1, value1, key2, value2, key3, value)
else new Map4(key1, value1, key2, value2, key3, value3, key, value)
def - (key: A): Map[A, B] =
if (key == key1) new Map2(key2, value2, key3, value3)
else if (key == key2) new Map2(key1, value1, key3, value3)
else if (key == key3) new Map2(key1, value1, key2, value2)
else this
}
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