| <!DOCTYPE html |
| PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "../xhtml1-strict.dtd"> |
| <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> |
| <head> |
| <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> |
| <link rel="stylesheet" type="text/css" href="../css/ot.css" /> |
| <link rel="stylesheet" type="text/css" href="../css/otjld.css" /> |
| <title>OT/J Language Definition v1.3</title> |
| </head> |
| <body class="otdt"> |
| <div id="content"> |
| <table class="nav"> |
| <tr> |
| <td class="back"><a id="top"></a><a href="s1.2.3.html" rel="prev"><< §1.2.3 Protected roles</a></td> |
| <td class="top"><a href="index.html" rel="contents">↑ Table of Contents ↑</a></td> |
| <td class="next"><a href="s1.2.5.html" rel="next">§1.2.5 File structure >></a></td> |
| </tr> |
| </table> |
| <div class="breadcrumb"><a class="nav" href="s1.html" rel="section">§1 Teams and Roles</a> > <a class="nav" href="s1.2.html" rel="section">§1.2 Role classes and objects</a></div> |
| <div class="sect depth3" id="s1.2.4"> |
| <h3 class="sect">§1.2.4 Type tests and casts<a class="img" href="s1.2.4.html" |
| title="PermaLink to §1.2.4 Type tests and casts"><img style="vertical-align:text-top;margin-left:5px;" src="../images/permalink.png" |
| alt="" /></a></h3> |
| <p>In accordance with <a href="s1.2.2.e.html" title="§1.2.2.(e) Conformance" class="sect">§1.2.2.(e)</a>, in OT/J |
| the <code>instanceof</code> operator and type casts have extended semantics for roles. |
| |
| </p> |
| <div class="subsect depth4" id="s1.2.4.a"> |
| <h4 class="subsect">(a) <span class="title">instanceof</span><a class="img" href="s1.2.4.a.html" title="PermaLink to (a) instanceof"><img style="vertical-align:text-top;margin-left:5px;" src="../images/permalink.png" |
| alt="" /></a></h4> |
| <p>For role types the <code>instanceof</code> operator yields true only if |
| both components of the type match: the dynamic role type must be compatible |
| to the given static type, and also type anchors must be the same instance. |
| |
| </p> |
| </div> |
| <div class="subsect depth4" id="s1.2.4.b"> |
| <h4 class="subsect">(b) <span class="title">Casting</span><a class="img" href="s1.2.4.b.html" title="PermaLink to (b) Casting"><img style="vertical-align:text-top;margin-left:5px;" src="../images/permalink.png" |
| alt="" /></a></h4> |
| <p>Casts may also fail if the casted expression is anchored to a different |
| team instance than the cast type. Such failure is signaled by a |
| <code>org.objectteams.RoleCastException</code>. |
| |
| </p> |
| </div> |
| <div class="subsect depth4" id="s1.2.4.c"> |
| <h4 class="subsect">(c) <span class="title">Class literal</span><a class="img" href="s1.2.4.c.html" title="PermaLink to (c) Class literal"><img style="vertical-align:text-top;margin-left:5px;" src="../images/permalink.png" |
| alt="" /></a></h4> |
| <p>A class literal of form <code>R.class</code> is dynamically bound to the class <code>R</code> |
| visible in the current instance context. Using a class literal for a role outside its |
| enclosing team instance (see <a href="s1.2.2.html" title="§1.2.2 Externalized roles" class="sect">§1.2.2</a>) requires the following syntax: |
| |
| </p> |
| <div class="listing plain"><pre>RoleClass<em><@teamAnchor></em><strong>.class</strong></pre></div> |
| </div> |
| </div> |
| <table class="nav"> |
| <tr> |
| <td class="back"><a href="s1.2.3.html" rel="prev"><< §1.2.3 Protected roles</a></td> |
| <td class="top"><a href="index.html" rel="contents">↑ Table of Contents ↑</a></td> |
| <td class="next"><a href="s1.2.5.html" rel="next">§1.2.5 File structure >></a></td> |
| </tr> |
| </table> |
| <div class="breadcrumb"><a class="nav" href="s1.html" rel="section">§1 Teams and Roles</a> > <a class="nav" href="s1.2.html" rel="section">§1.2 Role classes and objects</a></div> |
| </div> |
| <div id="footer"> |
| <hr /><a class="w3c img" href="http://jigsaw.w3.org/css-validator/check/referer" |
| shape="rect"><img src="../images/valid-css2-blue.png" alt="Valid CSS!" height="31" width="88" /></a><a class="w3c img" href="http://validator.w3.org/check?uri=referer" shape="rect"><img src="../images/valid-xhtml10-blue.png" alt="Valid XHTML 1.0 Strict" height="31" |
| width="88" /></a><address>© Stephan Herrmann, Christine Hundt, Marco Mosconi</address> |
| OT/J version 1.3 — last modified: 2010-05-18 |
| </div> |
| </body> |
| </html> |