alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Scala example source code file (DefaultMap.scala)

This example Scala source code file (DefaultMap.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Scala tags/keywords

a, a, b, b, b1, b1, defaultmap, map, map

The Scala DefaultMap.scala source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2011, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */



package scala.collection

import generic._

/** <p>
 *    A default map which implements the <code>+ and -
 *    methods of maps.<br/>
 *    Instances that inherit from <code>DefaultMap[A, B] still have to
 *    define:
 *  </p>
 *    <b>def get(key: A): Option[B]
 *    <b>def iterator: Iterator[(A, B)]
* <p> * It refers back to the original map. * </p> * <p> * It might also be advisable to override <code>foreach or * <code>size if efficient implementations can be found. * </p> * * @since 2.8 */ trait DefaultMap[A, +B] extends Map[A, B] { self => /** A default implementation which creates a new immutable map. */ override def +[B1 >: B](kv: (A, B1)): Map[A, B1] = { val b = Map.newBuilder[A, B1] b ++= this b += ((kv._1, kv._2)) b.result } /** A default implementation which creates a new immutable map. */ override def - (key: A): Map[A, B] = { val b = newBuilder b ++= this filter (key !=) b.result } }

Other Scala examples (source code examples)

Here is a short list of links related to this Scala DefaultMap.scala source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.