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				5	<title>Object Teams Introduction</title>
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				10	<td align="right">next: <a href="guide/develop.html">OTDT User Guide</a></td></tr>
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				13	<div id="content" style="margin-left:0px;padding-top:5px;">
				14	<p class="center">»<i>Programming with roles and beyond.</i>«</p>
				15	<div class="headl">
				16	<div class="headr">
				17	<h1>Why Object Teams?</h1>
				18	</div>
				19	</div>
				20	<div class="intro">
				21	<div class="line"></div>
				22	<div class="term">Team spirit for objects</div>
				23	<div class="termdesc">
				24	Building complex systems from isolated objects often yields poor
				25	structure which readily decays during system evolution.
				26	Objects should <b>team-up</b> in order to co-operate and jointly
				27	deliver complex behaviors.
				28	Objects play specific <b>roles</b> within a given Team.
				29	</div>
				30	<div class="line"></div>
				31	<div class="term">Context based dispatch</div>
				32	<div class="termdesc">
				33	Object behavior is controled by the currently active
				34	<b>context</b> of execution. Contexts are reified into
				35	<b>Team instances</b>, which may be used to mediate
				36	between roles and maintain state of the collaboration.
				37	</div>
				38	<div class="line"></div>
				39	<div class="term">Modules larger than classes</div>
				40	<div class="termdesc">
				41	On the road to re-use of modules larger than classes two
				42	approaches compete: <b>frameworks</b> and <b>components</b>.
				43	For many applications white box frameworks are too fragile and
				44	black box components to rigid.
				45	Object Teams provide a middle road which balances
				46	<b>encapsulation</b> and <b>adaptability</b>.
				47	</div>
				48	<div class="line"></div>
				49	</div>
				50
				51	<div class="headl">
				52	<div class="headr">
				53	<h1>Key Features of Object Teams</h1>
				54	</div>
				55	</div>
				56	<ul>
				57	<li>
				58	<div class="black">
				59	Weaving of aspect code into existing classes (no source code needed).
				60	</div>
				61	</li>
				62	<li>
				63	<div class="black">
				64	Teams are modules that encapsulate the interaction of
				65	a set of role objects.
				66	</div>
				67	<ul>
				68	<li>
				69	<div class="darkblue">
				70	Teams can be type-checked in a modular way.
				71	</div>
				72	</li>
				73	<li>
				74	<div class="darkblue">
				75	Roles are automatically managed by their enclosing
				76	Team instance.
				77	</div>
				78	</li>
				79	</ul>
				80	</li>
				81	<li>
				82	<div class="black">
				83	Teams can be refined using inheritance.
				84	</div>
				85	<ul>
				86	<li>
				87	<div class="darkblue">
				88	Collective refinement of role classes.
				89	</div>
				90	</li>
				91	<li>
				92	<div class="darkblue">
				93	Team refinement realizes type-safe covariance of
				94	role signatures.
				95	</div>
				96	</li>
				97	</ul>
				98	</li>
				99	<li>
				100	<div class="black">
				101	Teams are instantiable first class entities.
				102	</div>
				103	<ul>
				104	<li>
				105	<div class="darkblue">
				106	Teams are aspects that can be
				107	activated/deactivated at run-time.
				108	</div>
				109	</li>
				110	<li>
				111	<div class="darkblue">
				112	Roles may refer to their enclosing Team.
				113	</div>
				114	</li>
				115	</ul>
				116	</li>
				117	<li>
				118	<div class="black">
				119	Explicit connectors bind an abstract Team definition
				120	to a base package.
				121	</div>
				122	<ul>
				123	<li>
				124	<div class="darkblue">
				125	Binding happens a-posteriori, i.e., no modification
				126	in the base package is required.
				127	</div>
				128	</li>
				129	<li>
				130	<div class="darkblue">
				131	Team binding is specified in a declarative style.
				132	</div>
				133	</li>
				134	<li>
				135	<div class="darkblue">
				136	Bindings may specify different kinds of adaptations.
				137	</div>
				138	</li>
				139	</ul>
				140	</li>
				141	<li>
				142	<div class="black">
				143	Object Teams require a minimal number of new
				144	language constructs to be learned for a maximum of modularity and
				145	composability.
				146	</div>
				147	</li>
				148	</ul>
				149	</div>
				150	</body>
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