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 <html>
 <head>
 <title>Developers guide for Apache Commons "Collections" Package</title>
 </head>
 <body bgcolor="white">


 <div align="center">
 <h1>The Apache Commons <em>Collections</em> Package</h1>
 <h2>Developers Guide</h2>
 <a href="#Introduction">[Introduction]</a>
 <a href="#CollectionInterfaces">[Collection Interfaces]</a>
 <a href="#CollectionImplementations">[Collection Implementations]</a>
 <a href="#UtilityClasses">[Utility Classes]</a>
 <a href="#CodingStandards">[Coding Standards]</a>
 <br />
 <br />
 </div>


 <a name="Introduction"></a>
 <h3>1.  INTRODUCTION</h3>

 <p>The <em>Collections</em> package contains a set of Java classes that extend
 or augment the Java Collections Framework. This developers guide seeks to set
 out rules for the naming of classes and methods within the package. The purpose
 of this, as with all naming standards, is to improve the coherency and
 consistency of the whole API.</p>

 <p>The philosophy of the naming standards is to follow those of
 java.util.Collections.</p>


 <a name="CollectionInterfaces"></a>
 <h3>2.  COLLECTION INTERFACES</h3>

 <p>Collection interfaces are new types of collections not included in Java.
 Examples include <code>Bag</code> and <code>SortedBag</code>. These interfaces
 shall:</p>
 <ul>
 <li>be top level interfaces</li>
 <li>have a name that describes their purpose</li>
 </ul>


 <a name="CollectionImplementations"></a>
 <h3>3.  COLLECTION IMPLEMENTATIONS</h3>

 <p>Collection implementation are new implementations of collection interfaces.
 Examples include <code>DoubleOrderedMap</code> and <code>DefaultMapBag</code>.
 These interfaces shall:</p>
 <ul>
 <li>be top level classes</li>
 <li>have a name that ends with the collection type being implemented</li>
 <li>have a name that describes their implementation</li>
 <li>contain no public inner classes</li>
 <li>only contain the collection implementation, and any methods specific to
 that implementation</li>
 </ul>


 <a name="UtilityClasses"></a>
 <h3>4.  UTILITY CLASSES</h3>

 <p>Utility classes provide additional functionality around an interface and
 its basic implementations. Examples include CollectionUtils and ListUtils.</p>

 <p>Each class shall follow the naming pattern XxxUtils where Xxx relates to the
 object being returned by the class, for example <code>ListUtils</code> and
 <code>BagUtils</code>. Variations on a theme (<code>SortedBag</code> as opposed
 to <code>Bag</code>) will be dealt with in one Utils class. Each Utils class
 shall:</p>

 <ul>
 <li>be a single, static method based, class</li>
 <li>have a name consisting of the interface name plus 'Utils'</li>
 <li>deal with one collection interface and its variations</li>
 <li>provide methods that decorate the interface with additional
 functionality</li>
 <li>provide methods that perform useful utility functions on that
 interface</li>
 </ul>

 <p>Where the method in a Utils class is a decorator, the name shall consist of
 an adjective followed by the collection type.  Typically such adjective is
 formed by appending an -ed suffix (meaning "having"/"characterized by") to the
 word describing the type of decorator.  For example,
 <code>synchronizedMap(Map)</code> or <code>predicatedSet(Set)</code>.
 Occasionally, such construct is awkward and a more suitable adjective can be
 used instead.  For example, <code>lazyList</code>,
 <code>unmodifiableList</code>.</p>

 <p>These decorators should be implemented either as non-public, static,
 inner classes, or as public classes in a subpackage. If a subpackage is used,
 the constructors should be protected and a public static decorate() method
 provided on each class for construction.</p>

 <a name="CodingStandards"></a>
 <h3>5. CODING STANDARDS</h3>

 <p>Commons Collections follows similar style rules to many other Java open source
 projects, and the Sun conventions. Some specific conventions are:</p>

 <ul>
 <li>No tabs, 4 space indentations</li>
 <li>Curly brackets open at line end</li>
 <li>Else, catch and finally statements after the closing bracket</li>
 <li>Single space after keyword such as if</li>
 <li>Two spaces between parameter name and description in @param</li>
 <li>Generally copy the style of the surrounding code</li>
 </ul>

 <p>And remember, the commons-dev mailing list is there for any discussions
 or queries about patches or new additions to collections.</p>

 </body>
 </html>
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	this work for additional information regarding copyright ownership.
	The ASF licenses this file to You under the Apache License, Version 2.0
	(the "License"); you may not use this file except in compliance with
	the License. You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
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	See the License for the specific language governing permissions and
	limitations under the License.
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	<html>
	<head>
	<title>Developers guide for Apache Commons "Collections" Package</title>
	</head>
	<body bgcolor="white">


	<div align="center">
	<h1>The Apache Commons <em>Collections</em> Package</h1>
	<h2>Developers Guide</h2>
	<a href="#Introduction">[Introduction]</a>
	<a href="#CollectionInterfaces">[Collection Interfaces]</a>
	<a href="#CollectionImplementations">[Collection Implementations]</a>
	<a href="#UtilityClasses">[Utility Classes]</a>
	<a href="#CodingStandards">[Coding Standards]</a>
	<br />
	<br />
	</div>


	<a name="Introduction"></a>
	<h3>1. INTRODUCTION</h3>

	<p>The <em>Collections</em> package contains a set of Java classes that extend
	or augment the Java Collections Framework. This developers guide seeks to set
	out rules for the naming of classes and methods within the package. The purpose
	of this, as with all naming standards, is to improve the coherency and
	consistency of the whole API.</p>

	<p>The philosophy of the naming standards is to follow those of
	java.util.Collections.</p>


	<a name="CollectionInterfaces"></a>
	<h3>2. COLLECTION INTERFACES</h3>

	<p>Collection interfaces are new types of collections not included in Java.
	Examples include <code>Bag</code> and <code>SortedBag</code>. These interfaces
	shall:</p>
	<ul>
	<li>be top level interfaces</li>
	<li>have a name that describes their purpose</li>
	</ul>


	<a name="CollectionImplementations"></a>
	<h3>3. COLLECTION IMPLEMENTATIONS</h3>

	<p>Collection implementation are new implementations of collection interfaces.
	Examples include <code>DoubleOrderedMap</code> and <code>DefaultMapBag</code>.
	These interfaces shall:</p>
	<ul>
	<li>be top level classes</li>
	<li>have a name that ends with the collection type being implemented</li>
	<li>have a name that describes their implementation</li>
	<li>contain no public inner classes</li>
	<li>only contain the collection implementation, and any methods specific to
	that implementation</li>
	</ul>


	<a name="UtilityClasses"></a>
	<h3>4. UTILITY CLASSES</h3>

	<p>Utility classes provide additional functionality around an interface and
	its basic implementations. Examples include CollectionUtils and ListUtils.</p>

	<p>Each class shall follow the naming pattern XxxUtils where Xxx relates to the
	object being returned by the class, for example <code>ListUtils</code> and
	<code>BagUtils</code>. Variations on a theme (<code>SortedBag</code> as opposed
	to <code>Bag</code>) will be dealt with in one Utils class. Each Utils class
	shall:</p>

	<ul>
	<li>be a single, static method based, class</li>
	<li>have a name consisting of the interface name plus 'Utils'</li>
	<li>deal with one collection interface and its variations</li>
	<li>provide methods that decorate the interface with additional
	functionality</li>
	<li>provide methods that perform useful utility functions on that
	interface</li>
	</ul>

	<p>Where the method in a Utils class is a decorator, the name shall consist of
	an adjective followed by the collection type. Typically such adjective is
	formed by appending an -ed suffix (meaning "having"/"characterized by") to the
	word describing the type of decorator. For example,
	<code>synchronizedMap(Map)</code> or <code>predicatedSet(Set)</code>.
	Occasionally, such construct is awkward and a more suitable adjective can be
	used instead. For example, <code>lazyList</code>,
	<code>unmodifiableList</code>.</p>

	<p>These decorators should be implemented either as non-public, static,
	inner classes, or as public classes in a subpackage. If a subpackage is used,
	the constructors should be protected and a public static decorate() method
	provided on each class for construction.</p>

	<a name="CodingStandards"></a>
	<h3>5. CODING STANDARDS</h3>

	<p>Commons Collections follows similar style rules to many other Java open source
	projects, and the Sun conventions. Some specific conventions are:</p>

	<ul>
	<li>No tabs, 4 space indentations</li>
	<li>Curly brackets open at line end</li>
	<li>Else, catch and finally statements after the closing bracket</li>
	<li>Single space after keyword such as if</li>
	<li>Two spaces between parameter name and description in @param</li>
	<li>Generally copy the style of the surrounding code</li>
	</ul>

	<p>And remember, the commons-dev mailing list is there for any discussions
	or queries about patches or new additions to collections.</p>

	</body>
	</html>