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| <div class="breadcrumb"><a class="nav" href="s5.html" rel="section">§5 Team Activation</a> > <a class="nav" href="s5.4.html" rel="section">§5.4 Guard predicates</a></div> |
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| <h4 class="subsect">§5.4.(a) <span class="title">General syntax for guards</span><a class="img" href="s5.4.a.html" |
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| <p>A guard is declared using the keyword <code>when</code> followed by a |
| boolean expression in parentheses: |
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| <div class="listing plain"><pre><em><b>when</b> (</em><i>predicateExpression</i><em>)</em></pre></div> |
| <p>Depending on the kind of guard different objects are in scope using |
| special identifiers like <code>this</code>, <code>base</code>.<br /> |
| Any predicate expression that evaluates to <code>true</code> enables |
| the callin binding(s) to which it applies. |
| Evaluation to <code>false</code> disables the callin binding(s). |
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| OT/J version 1.3 — last modified: 2011-05-15 |
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