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12.10.1 内联约束检查器</div>
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通常，调用一个没有随机变量的类的<span style="color: #0000FF">randomize</span>方法会导致这个方法作为一个检查器使用，也就是说它不会赋随机值，而是仅仅返回一个状态：如果所有的约束都被满足返回1，否则返回0。内联随机变量控制机制还可以用来强制<span style="color: #0000FF">randomize</span><span style="color: #800080">()</span>方法作为一个检查器使用。 </p>
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<span style="color: #0000FF">randomize</span>方法可以接受特殊的参数<span style="color: #FF0000">null</span>，它用来指示在调用期内没有随机变量。也就是说，所有的类成员均作为状态变量使用。这会导致<span style="color: #0000FF">randomize</span>方法作为一个检查器使用而不是作为一个产生器使用。一个检查器会计算所有的约束并简单地在所有的约束都被满足时返回1，否则返回0。例如，如果上面定义的类CA执行了下列的调用： </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00452"><pre class="Element12">success <span style="color: #800080">=</span> a<span style="color: #800080">.</span><span style="color: #0000FF">randomize</span><span style="color: #800080">(</span><span style="color: #FF0000">null</span><span style="color: #800080">);</span> <span style="color: #008000">// 没有随机变量</span></pre></div></div>
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那么，求解器将所有的变量作为状态变量使用，并仅仅检查约束是否满足，也就是检查当使用<span class="Element146">x</span>、<span class="Element146">y</span>、<span class="Element146">v</span>和<span class="Element146">w</span>的当前值的时候<span class="Element146"><span style="color: #800080">(</span>x <span style="color: #800080"><</span> v <span style="color: #800080">&&</span> y <span style="color: #800080">></span> w<span style="color: #800080">)</span></span>的关系是否为真。</p></div>
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