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Breadcrumbs go here --> <li><a href="modules.html">Modules</a></li> <li><a href="qtscript.html">QtScript</a></li> <li>QScriptEngine</li> </ul> </div> <div class="toolbuttons toolblock"> <ul> <li id="smallA" class="t_button">A</li> <li id="medA" class="t_button active">A</li> <li id="bigA" class="t_button">A</li> <li id="print" class="t_button"><a href="javascript:this.print();"> <span>Print</span></a></li> </ul> </div> </div> <div class="content mainContent"> <h1 class="title">Obsolete Members for QScriptEngine</h1> <p><b>The following class members are obsolete.</b> They are provided to keep old source code working. We strongly advise against using them in new code.</p> <p><ul><li><a href="qscriptengine.html">QScriptEngine class reference</a></li></ul></p> <h2>Public Functions</h2> <table class="alignedsummary"> <tr><td class="memItemLeft topAlign rightAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qscriptengine-obsolete.html#canEvaluate">canEvaluate</a></b> ( const QString & <i>program</i> ) const<tt> (obsolete)</tt></td></tr> </table> <h2>Related Non-Members</h2> <table class="alignedsummary"> <tr><td class="memItemLeft topAlign rightAlign"> QScriptValue </td><td class="memItemRight bottomAlign"><b><a href="qscriptengine-obsolete.html#qScriptValueFromValue">qScriptValueFromValue</a></b> ( QScriptEngine * <i>engine</i>, const T & <i>value</i> )<tt> (obsolete)</tt></td></tr> </table> <h2>Member Function Documentation</h2> <!-- $$$canEvaluate[overload1]$$$canEvaluateconstQString& --> <h3 class="fn"><a name="canEvaluate"></a><span class="type">bool</span> QScriptEngine::<span class="name">canEvaluate</span> ( const <span class="type"><a href="qstring.html">QString</a></span> & <i>program</i> ) const</h3> <p>Returns true if <i>program</i> can be evaluated; i.e. the code is sufficient to determine whether it appears to be a syntactically correct program, or contains a syntax error.</p> <p>This function returns false if <i>program</i> is incomplete; i.e. the input is syntactically correct up to the point where the input is terminated.</p> <p>Note that this function only does a static check of <i>program</i>; e.g. it does not check whether references to variables are valid, and so on.</p> <p>A typical usage of canEvaluate() is to implement an interactive interpreter for <a href="qtscript.html">QtScript</a>. The user is repeatedly queried for individual lines of code; the lines are concatened internally, and only when canEvaluate() returns true for the resulting program is it passed to <a href="qscriptengine.html#evaluate">evaluate</a>().</p> <p>The following are some examples to illustrate the behavior of canEvaluate(). (Note that all example inputs are assumed to have an explicit newline as their last character, since otherwise the <a href="qtscript.html">QtScript</a> parser would automatically insert a semi-colon character at the end of the input, and this could cause canEvaluate() to produce different results.)</p> <p>Given the input</p> <pre class="cpp"> <span class="keyword">if</span> (hello <span class="operator">&</span><span class="operator">&</span> world) print(<span class="string">"hello world"</span>);</pre> <p>canEvaluate() will return true, since the program appears to be complete.</p> <p>Given the input</p> <pre class="cpp"> <span class="keyword">if</span> (hello <span class="operator">&</span><span class="operator">&</span></pre> <p>canEvaluate() will return false, since the if-statement is not complete, but is syntactically correct so far.</p> <p>Given the input</p> <pre class="cpp"> <span class="number">0</span> <span class="operator">=</span> <span class="number">0</span></pre> <p>canEvaluate() will return true, but <a href="qscriptengine.html#evaluate">evaluate</a>() will throw a SyntaxError given the same input.</p> <p>Given the input</p> <pre class="cpp"> <span class="operator">.</span><span class="operator">/</span>test<span class="operator">.</span>js</pre> <p>canEvaluate() will return true, even though the code is clearly not syntactically valid <a href="qtscript.html">QtScript</a> code. <a href="qscriptengine.html#evaluate">evaluate</a>() will throw a SyntaxError when this code is evaluated.</p> <p>Given the input</p> <pre class="cpp"> foo<span class="operator">[</span><span class="string">"bar"</span><span class="operator">]</span></pre> <p>canEvaluate() will return true, but <a href="qscriptengine.html#evaluate">evaluate</a>() will throw a ReferenceError if <tt>foo</tt> is not defined in the script environment.</p> <p><b>See also </b><a href="qscriptengine.html#evaluate">evaluate</a>() and <a href="qscriptengine.html#checkSyntax">checkSyntax</a>().</p> <!-- @@@canEvaluate --> <h2>Related Non-Members</h2> <!-- $$$qScriptValueFromValue[overload1]$$$qScriptValueFromValueQScriptEngine*constT& --> <h3 class="fn"><a name="qScriptValueFromValue"></a><span class="type"><a href="qscriptvalue.html">QScriptValue</a></span> <span class="name">qScriptValueFromValue</span> ( <span class="type">QScriptEngine</span> * <i>engine</i>, const <span class="type">T</span> & <i>value</i> )</h3> <p>Creates a <a href="qscriptvalue.html">QScriptValue</a> using the given <i>engine</i> with the given <i>value</i> of template type <tt>T</tt>.</p> <p>This function is equivalent to <a href="qscriptengine.html#toScriptValue">QScriptEngine::toScriptValue</a>().</p> <p><b>Note:</b> This function was provided as a workaround for MSVC 6 which did not support member template functions. It is advised to use the other form in new code.</p> <p>This function was introduced in Qt 4.3.</p> <p><b>See also </b><a href="qscriptengine.html#toScriptValue">QScriptEngine::toScriptValue</a>() and <a href="qscriptvalue.html#qscriptvalue_cast">qscriptvalue_cast</a>().</p> <!-- @@@qScriptValueFromValue --> </div> </div> </div> <div class="ft"> <span></span> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2013 Digia Plc and/or its subsidiaries. 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