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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2009, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala.collection.immutable
import generic._
trait Map[A, +B] extends Iterable[(A, B)]
with collection.Map[A, B]
with ImmutableMapTemplate[A, B, Map[A, B]] { self =>
override def empty: Map[A, B] = Map.empty
override def mapBuilder[A, B]: Builder[(A, B), Map[A, B]] = Map.newBuilder[A, B]
/** Add a key/value pair to this map.
* @param key the key
* @param value the value
* @return A new map with the new binding added to this map
*/
override def updated [B1 >: B](key: A, value: B1): Map[A, B1]
def + [B1 >: B](kv: (A, B1)): Map[A, B1]
/** A hash method compatible with <code>equals</code>
*/
override def hashCode() =
(Map.hashSeed /: this) (_ * 41 + _.hashCode)
/** The same map with a given default function !!! todo: move to general maps? */
def withDefault[B1 >: B](d: A => B1): Map[A, B1] = new Map.WithDefault[A, B1](this, d)
/** The same map with a given default value */
def withDefaultValue[B1 >: B](d: B1): Map[A, B1] = new Map.WithDefault[A, B1](this, x => d)
}
object Map extends ImmutableMapFactory[Map] {
private val hashSeed = "Map".hashCode
type Coll = Map[_, _]
implicit def builderFactory[A, B]: BuilderFactory[(A, B), Map[A, B], Coll] = new BuilderFactory[(A, B), Map[A, B], Coll] { def apply(from: Coll) = from.mapBuilder[A, B] }
def empty[A, B]: Map[A, B] = FlexMap.empty
class WithDefault[A, +B](underlying: Map[A, B], d: A => B) extends Map[A, B] {
override def size = underlying.size
def get(key: A) = underlying.get(key)
def elements = underlying.elements
override def empty = new WithDefault(underlying.empty, d)
override def updated[B1 >: B](key: A, value: B1): WithDefault[A, B1] = new WithDefault[A, B1](underlying.updated[B1](key, value), d)
def + [B1 >: B](kv: (A, B1)): WithDefault[A, B1] = updated(kv._1, kv._2)
def - (key: A): WithDefault[A, B] = new WithDefault(underlying - key, d)
override def default(key: A): B = d(key)
}
}
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