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<ppdoc>
<copyright>
Copyright (c) 2001 by Addison Wesley Longman. This
material may be distributed only subject to the terms and
conditions set forth in the Open Publication License, v1.0 or
later (the latest version is presently available at
http://www.opencontent.org/openpub/).
</copyright>
<class name="Symbol" super="Object" type="class">
<p/>
A <classname>Symbol</classname> object represents a Ruby name and is generated
automatically using the <tt>:name</tt> literal syntax. The same <classname>Symbol</classname>
object will be created for a given name string for the duration of a
program's execution, regardless of the context or meaning of that
name. Thus if <tt>Fred</tt> is a constant in one context, a method in
another, and a class in a third, the <classname>Symbol</classname> <tt>:Fred</tt> will be
the same object in all three contexts.
<p/>
<codefragment>
<fullcode><![CDATA[ module One
class Fred
end
$f1 = :Fred
end
module Two
Fred = 1
$f2 = :Fred
end
def Fred()
end
$f3 = :Fred
$f1.id
$f2.id
$f3.id
]]></fullcode><rubycode>
<tr>
<td colspan="3"><tt>module<nbsp/>One</tt></td>
</tr>
<tr>
<td colspan="3"><tt><nbsp/><nbsp/>class<nbsp/>Fred</tt></td>
</tr>
<tr>
<td colspan="3"><tt><nbsp/><nbsp/>end</tt></td>
</tr>
<tr>
<td colspan="3"><tt><nbsp/><nbsp/>$f1<nbsp/>=<nbsp/>:Fred</tt></td>
</tr>
<tr>
<td colspan="3"><tt>end</tt></td>
</tr>
<tr>
<td colspan="3"><tt>module<nbsp/>Two</tt></td>
</tr>
<tr>
<td colspan="3"><tt><nbsp/><nbsp/>Fred<nbsp/>=<nbsp/>1</tt></td>
</tr>
<tr>
<td colspan="3"><tt><nbsp/><nbsp/>$f2<nbsp/>=<nbsp/>:Fred</tt></td>
</tr>
<tr>
<td colspan="3"><tt>end</tt></td>
</tr>
<tr>
<td colspan="3"><tt>def<nbsp/>Fred()</tt></td>
</tr>
<tr>
<td colspan="3"><tt>end</tt></td>
</tr>
<tr>
<td colspan="3"><tt>$f3<nbsp/>=<nbsp/>:Fred</tt></td>
</tr>
<tr>
<td><tt>$f1.id</tt></td>
<td>»</td>
<td><tt>2299150</tt></td>
</tr>
<tr>
<td><tt>$f2.id</tt></td>
<td>»</td>
<td><tt>2299150</tt></td>
</tr>
<tr>
<td><tt>$f3.id</tt></td>
<td>»</td>
<td><tt>2299150</tt></td>
</tr>
</rubycode>
<p/>
</codefragment>
<p/>
<methods type="instance">
<method name="id2name" ref="id2name">
<callseq>
<obj>sym</obj>.id2name <returns><obj>aString</obj></returns>
</callseq>
<desc>
<p/>
Returns the name corresponding to <obj>sym</obj>.
<p/>
<codefragment>
<fullcode><![CDATA[ :fred.id2name
]]></fullcode><rubycode>
<tr>
<td><tt>:fred.id2name</tt></td>
<td>»</td>
<td><tt>"fred"</tt></td>
</tr>
</rubycode>
<p/>
</codefragment>
<p/>
</desc>
</method>
<p/>
<method name="inspect" ref="inspect">
<callseq>
<obj>sym</obj>.inspect <returns><obj>aString</obj></returns>
</callseq>
<desc>
<p/>
Returns the representation of <obj>sym</obj> as a symbol literal.
<p/>
<codefragment>
<fullcode><![CDATA[ :fred.inspect
]]></fullcode><rubycode>
<tr>
<td><tt>:fred.inspect</tt></td>
<td>»</td>
<td><tt>":fred"</tt></td>
</tr>
</rubycode>
<p/>
</codefragment>
<p/>
</desc>
</method>
<p/>
<method name="to_i" ref="to_i">
<callseq>
<obj>sym</obj>.to_i <returns><obj>aFixnum</obj></returns>
</callseq>
<desc>
<p/>
Returns an integer that is unique for each symbol within a
particular execution of a program.
<p/>
</desc>
</method>
<p/>
<method name="to_s" ref="to_s">
<callseq>
<obj>sym</obj>.to_s <returns><obj>aString</obj></returns>
</callseq>
<desc>
<p/>
Synonym for <cim><file>symbol</file><front>Symbol</front><back>id2name</back><mref>id2name</mref></cim>.
<p/>
</desc>
</method>
<p/>
</methods>
<p/>
</class>
</ppdoc>
|
