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

Scala example source code file (WrappedArrayBuilder.scala)

This example Scala source code file (WrappedArrayBuilder.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, builder, classmanifest, int, int, wrappedarray, wrappedarray, wrappedarraybuilder, wrappedarraybuilder

The Scala WrappedArrayBuilder.scala source code

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



package scala.collection
package mutable

import generic._
import scala.reflect.ClassManifest

/** A builder class for arrays.
 *  
 *  @tparam A         type of elements that can be added to this builder.
 *  @param manifest   class manifest for objects of type `A`.
 *  
 *  @since 2.8
 */
class WrappedArrayBuilder[A](manifest: ClassManifest[A]) extends Builder[A, WrappedArray[A]] {

  private var elems: WrappedArray[A] = _
  private var capacity: Int = 0
  private var size: Int = 0

  private def mkArray(size: Int): WrappedArray[A] = {
    val newelems = manifest.newWrappedArray(size)
    if (this.size > 0) Array.copy(elems.array, 0, newelems.array, 0, this.size)
    newelems
  }

  private def resize(size: Int) {
    elems = mkArray(size)
    capacity = size
  }
  
  override def sizeHint(size: Int) {
    if (capacity < size) resize(size)
  }

  private def ensureSize(size: Int) {
    if (capacity < size) {
      var newsize = if (capacity == 0) 16 else capacity * 2
      while (newsize < size) newsize *= 2
      resize(newsize)
    }
  } 
  
  def +=(elem: A): this.type = {
    ensureSize(size + 1)
    elems(size) = elem
    size += 1
    this
  }

  def clear() {
    size = 0
  }

  def result() = {
    if (capacity != 0 && capacity == size) elems 
    else mkArray(size)
  }

  // todo: add ++=
}

Other Scala examples (source code examples)

Here is a short list of links related to this Scala WrappedArrayBuilder.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.