t;&gt; v.x = 3
&gt;&gt;&gt; v.y = 4
&gt;&gt;&gt; v.z = -13
&gt;&gt;&gt; ...
&gt;&gt;&gt; del v
</pre></div>

<p>
Similarly, in Perl5 you may want the interface to work like this:</p>

<div class="targetlang"><pre>
$v = new Vector;
$v-&gt;{x} = 3;
$v-&gt;{y} = 4;
$v-&gt;{z} = -13;

</pre></div>
<p>
Finally, in Tcl :
</p>

<div class="targetlang"><pre>
Vector v
v configure -x 3 -y 4 -z -13

</pre></div>

<p>
When proxy classes are used, two objects are really at work--one in
the scripting language, and an und