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| <td class="top"><a href="index.html" rel="contents">↑ Table of Contents ↑</a></td> |
| <td class="next"><a href="s2.3.2.b.html" rel="next">§2.3.2.(b) Super in the context of declared lifting >></a></td> |
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| <div class="breadcrumb"><a class="nav" href="s2.html" rel="section">§2 Role Binding</a> > <a class="nav" href="s2.3.html" rel="section">§2.3 Lifting</a> > <a class="nav" href="s2.3.2.html" rel="section">§2.3.2 Declared lifting</a></div> |
| <div class="subsect depth4" id="s2.3.2.a"> |
| <h4 class="subsect">§2.3.2.(a) <span class="title">Parameters with declared lifting</span><a class="img" href="s2.3.2.a.html" |
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| <p>A non-static team-level method or constructor may declare a parameter with two types |
| in order to explicitly denote a place of <strong>lifting</strong>. Using the syntax |
| |
| </p> |
| <div class="listing plain"><pre><b>public</b> <b>void</b> m (BaseClass <em>as</em> RoleClass param) { <i>stmts</i> }</pre></div> |
| <p>a liftable parameter can be declared, provided the second type |
| (<code>RoleClass</code>) is a role of (<code>playedBy</code>) the first type (<code>BaseClass</code>). |
| Furthermore, the role type must be a role of the enclosing team class defining the given method. |
| The role type must be given by its simple (i.e., unqualified) name. |
| <br /> |
| Such a signature requires the caller to provide a base object (here <code>BaseClass</code>), but |
| the callee receives a role object (here <code>RoleClass</code>). |
| In fact, the client sees a signature in which the "<code>as RoleClass</code>" part is omitted. |
| <br /> |
| Compatibility between caller and callee sides is achieved by an implicitly inserted lifting translation. |
| A signature using declared lifting is only valid, if the requested lifting is possible |
| (see <a href="s2.3.3.html" title="§2.3.3 Smart lifting" class="sect">§2.3.3</a> and <a href="s2.3.4.html" title="§2.3.4 Binding ambiguities" |
| class="sect">§2.3.4</a> for details). |
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| <div class="breadcrumb"><a class="nav" href="s2.html" rel="section">§2 Role Binding</a> > <a class="nav" href="s2.3.html" rel="section">§2.3 Lifting</a> > <a class="nav" href="s2.3.2.html" rel="section">§2.3.2 Declared lifting</a></div> |
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| width="88" /></a><address>© Stephan Herrmann, Christine Hundt, Marco Mosconi</address> |
| OT/J version 1.3 — last modified: 2010-05-18 |
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