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| <tr><td colspan="5" class="shortcuts"> |
| <a href="#glib-Quarks.synopsis" class="shortcut">Top</a> |
| | |
| <a href="#glib-Quarks.description" class="shortcut">Description</a> |
| </td></tr> |
| </table> |
| <div class="refentry" title="Quarks"> |
| <a name="glib-Quarks"></a><div class="titlepage"></div> |
| <div class="refnamediv"><table width="100%"><tr> |
| <td valign="top"> |
| <h2><span class="refentrytitle"><a name="glib-Quarks.top_of_page"></a>Quarks</span></h2> |
| <p>Quarks — a 2-way association between a string and a |
| unique integer identifier</p> |
| </td> |
| <td valign="top" align="right"></td> |
| </tr></table></div> |
| <div class="refsynopsisdiv" title="Synopsis"> |
| <a name="glib-Quarks.synopsis"></a><h2>Synopsis</h2> |
| <pre class="synopsis"> |
| #include <glib.h> |
| |
| typedef <a class="link" href="glib-Quarks.html#GQuark" title="GQuark">GQuark</a>; |
| <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="returnvalue">GQuark</span></a> <a class="link" href="glib-Quarks.html#g-quark-from-string" title="g_quark_from_string ()">g_quark_from_string</a> (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *string</code></em>); |
| <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="returnvalue">GQuark</span></a> <a class="link" href="glib-Quarks.html#g-quark-from-static-string" title="g_quark_from_static_string ()">g_quark_from_static_string</a> (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *string</code></em>); |
| const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a>* <a class="link" href="glib-Quarks.html#g-quark-to-string" title="g_quark_to_string ()">g_quark_to_string</a> (<em class="parameter"><code><a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> quark</code></em>); |
| <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="returnvalue">GQuark</span></a> <a class="link" href="glib-Quarks.html#g-quark-try-string" title="g_quark_try_string ()">g_quark_try_string</a> (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *string</code></em>); |
| const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a>* <a class="link" href="glib-Quarks.html#g-intern-string" title="g_intern_string ()">g_intern_string</a> (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *string</code></em>); |
| const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a>* <a class="link" href="glib-Quarks.html#g-intern-static-string" title="g_intern_static_string ()">g_intern_static_string</a> (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *string</code></em>); |
| </pre> |
| </div> |
| <div class="refsect1" title="Description"> |
| <a name="glib-Quarks.description"></a><h2>Description</h2> |
| <p> |
| Quarks are associations between strings and integer identifiers. |
| Given either the string or the <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> identifier it is possible to |
| retrieve the other. |
| </p> |
| <p> |
| Quarks are used for both Datasets and Keyed Data Lists. |
| </p> |
| <p> |
| To create a new quark from a string, use <a class="link" href="glib-Quarks.html#g-quark-from-string" title="g_quark_from_string ()"><code class="function">g_quark_from_string()</code></a> or |
| <a class="link" href="glib-Quarks.html#g-quark-from-static-string" title="g_quark_from_static_string ()"><code class="function">g_quark_from_static_string()</code></a>. |
| </p> |
| <p> |
| To find the string corresponding to a given <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a>, use |
| <a class="link" href="glib-Quarks.html#g-quark-to-string" title="g_quark_to_string ()"><code class="function">g_quark_to_string()</code></a>. |
| </p> |
| <p> |
| To find the <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> corresponding to a given string, use |
| <a class="link" href="glib-Quarks.html#g-quark-try-string" title="g_quark_try_string ()"><code class="function">g_quark_try_string()</code></a>. |
| </p> |
| <p> |
| Another use for the string pool maintained for the quark functions |
| is string interning, using <a class="link" href="glib-Quarks.html#g-intern-string" title="g_intern_string ()"><code class="function">g_intern_string()</code></a> or |
| <a class="link" href="glib-Quarks.html#g-intern-static-string" title="g_intern_static_string ()"><code class="function">g_intern_static_string()</code></a>. An interned string is a canonical |
| representation for a string. One important advantage of interned |
| strings is that they can be compared for equality by a simple |
| pointer comparision, rather than using <code class="function">strcmp()</code>. |
| </p> |
| </div> |
| <div class="refsect1" title="Details"> |
| <a name="glib-Quarks.details"></a><h2>Details</h2> |
| <div class="refsect2" title="GQuark"> |
| <a name="GQuark"></a><h3>GQuark</h3> |
| <pre class="programlisting">typedef guint32 GQuark; |
| </pre> |
| <p> |
| A GQuark is a non-zero integer which uniquely identifies a |
| particular string. A GQuark value of zero is associated to <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a>. |
| </p> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_quark_from_string ()"> |
| <a name="g-quark-from-string"></a><h3>g_quark_from_string ()</h3> |
| <pre class="programlisting"><a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="returnvalue">GQuark</span></a> g_quark_from_string (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *string</code></em>);</pre> |
| <p> |
| Gets the <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> identifying the given string. If the string does |
| not currently have an associated <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a>, a new <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> is created, |
| using a copy of the string. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>string</code></em> :</span></p></td> |
| <td>a string. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>the <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> identifying the string, or 0 if <em class="parameter"><code>string</code></em> is |
| <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a>. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_quark_from_static_string ()"> |
| <a name="g-quark-from-static-string"></a><h3>g_quark_from_static_string ()</h3> |
| <pre class="programlisting"><a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="returnvalue">GQuark</span></a> g_quark_from_static_string (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *string</code></em>);</pre> |
| <p> |
| Gets the <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> identifying the given (static) string. If the |
| string does not currently have an associated <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a>, a new <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> |
| is created, linked to the given string. |
| </p> |
| <p> |
| Note that this function is identical to <a class="link" href="glib-Quarks.html#g-quark-from-string" title="g_quark_from_string ()"><code class="function">g_quark_from_string()</code></a> except |
| that if a new <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> is created the string itself is used rather |
| than a copy. This saves memory, but can only be used if the string |
| will <span class="emphasis"><em>always</em></span> exist. It can be used with |
| statically allocated strings in the main program, but not with |
| statically allocated memory in dynamically loaded modules, if you |
| expect to ever unload the module again (e.g. do not use this |
| function in GTK+ theme engines). |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>string</code></em> :</span></p></td> |
| <td>a string. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>the <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> identifying the string, or 0 if <em class="parameter"><code>string</code></em> is |
| <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a>. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_quark_to_string ()"> |
| <a name="g-quark-to-string"></a><h3>g_quark_to_string ()</h3> |
| <pre class="programlisting">const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a>* g_quark_to_string (<em class="parameter"><code><a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> quark</code></em>);</pre> |
| <p> |
| Gets the string associated with the given <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>quark</code></em> :</span></p></td> |
| <td>a <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a>. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>the string associated with the <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a>. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_quark_try_string ()"> |
| <a name="g-quark-try-string"></a><h3>g_quark_try_string ()</h3> |
| <pre class="programlisting"><a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="returnvalue">GQuark</span></a> g_quark_try_string (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *string</code></em>);</pre> |
| <p> |
| Gets the <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> associated with the given string, or 0 if string is |
| <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a> or it has no associated <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a>. |
| </p> |
| <p> |
| If you want the GQuark to be created if it doesn't already exist, |
| use <a class="link" href="glib-Quarks.html#g-quark-from-string" title="g_quark_from_string ()"><code class="function">g_quark_from_string()</code></a> or <a class="link" href="glib-Quarks.html#g-quark-from-static-string" title="g_quark_from_static_string ()"><code class="function">g_quark_from_static_string()</code></a>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>string</code></em> :</span></p></td> |
| <td>a string. |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>the <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> associated with the string, or 0 if <em class="parameter"><code>string</code></em> is |
| <a class="link" href="glib-Standard-Macros.html#NULL:CAPS" title="NULL"><code class="literal">NULL</code></a> or there is no <a class="link" href="glib-Quarks.html#GQuark" title="GQuark"><span class="type">GQuark</span></a> associated with it. |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_intern_string ()"> |
| <a name="g-intern-string"></a><h3>g_intern_string ()</h3> |
| <pre class="programlisting">const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a>* g_intern_string (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *string</code></em>);</pre> |
| <p> |
| Returns a canonical representation for <em class="parameter"><code>string</code></em>. Interned strings can |
| be compared for equality by comparing the pointers, instead of using <code class="function">strcmp()</code>. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>string</code></em> :</span></p></td> |
| <td>a string |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> a canonical representation for the string |
| |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <p class="since">Since 2.10</p> |
| </div> |
| <hr> |
| <div class="refsect2" title="g_intern_static_string ()"> |
| <a name="g-intern-static-string"></a><h3>g_intern_static_string ()</h3> |
| <pre class="programlisting">const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="returnvalue">gchar</span></a>* g_intern_static_string (<em class="parameter"><code>const <a class="link" href="glib-Basic-Types.html#gchar" title="gchar"><span class="type">gchar</span></a> *string</code></em>);</pre> |
| <p> |
| Returns a canonical representation for <em class="parameter"><code>string</code></em>. Interned strings can |
| be compared for equality by comparing the pointers, instead of using <code class="function">strcmp()</code>. |
| <a class="link" href="glib-Quarks.html#g-intern-static-string" title="g_intern_static_string ()"><code class="function">g_intern_static_string()</code></a> does not copy the string, therefore <em class="parameter"><code>string</code></em> must |
| not be freed or modified. |
| </p> |
| <div class="variablelist"><table border="0"> |
| <col align="left" valign="top"> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>string</code></em> :</span></p></td> |
| <td>a static string |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> a canonical representation for the string |
| |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <p class="since">Since 2.10</p> |
| </div> |
| </div> |
| </div> |
| <div class="footer"> |
| <hr> |
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