Ok, but this means I have to worry of the receiver&#39;s class before I send collect:, so as I don&#39;t fuck it all up.... and I don&#39;t want to think about that!!! See, if I want the collection of grades of the students, I would like to do this:<div>

<br></div><div>grades</div><div>^self students collect: [.aStudent | aStudent grades]</div><div><br></div><div>�regardless of whatever is the class of students... This does the trick for all the collections, except for Set. And I don�t know if students is an instance of Set, and I really don&#39;t want to think if it is or not. If I don&#39;t want repeated students and I create my collection as an instance of Set, an i.e.; I want to calculate the average, then I&#39;m screwed because the collection I get from the collect: wasn&#39;t the want that I wanted.�</div>

<div>So, I have to know previously that my collection is an instance of Set, or if it isn&#39;t, so as to know if I have to convert it first....</div><div><br><div><div>And if I use collect: as:, as you suggest, this means the collections are no longer polymorphic for me :( �</div>

<div>Sorry, maybe I&#39;m really stupid, but I don&#39;t know how that message solves best the problem than redefining collect: for Set. For the particular case I don&#39;t want the repeated objects (which AFAIK is not so common) I could send asSet.�<br>

<br><div class="gmail_quote">On 27 October 2011 11:05, Henrik Sperre Johansen <span dir="ltr">&lt;<a href="mailto:henrik.s.johansen@veloxit.no">henrik.s.johansen@veloxit.no</a>&gt;</span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">

<div class="im">On 27.10.2011 15:40, Clara Allende wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
I know, but our students don&#39;t :) So they ran into problems because the message send didn&#39;t answer what they were specting.... �because it makes sense that if I want to transform the objects in my collection, I might get repeated objects... Maybe I&#39;m not thinking in terms of consistency, I&#39;m just putting myself on student&#39;s shoes :P<br>


</blockquote></div>
The consistency rule to remember for #collect:/#select:/#reject: is that they will return a collection of the receiver&#39;s species.<br>
#collect:as: was added as a general answer to the situation your students ran into :)<br>
<br>
set := Set withAll: #(1 2 3 4 5 6 7 8).<br>
result := set collect: #even as: Bag.<br>
<br>
Cheers,<br>
Henry<br>
<br>
<br>
<br>
</blockquote></div><br><br clear="all"><div><br></div>-- <br><blockquote><div style="text-align:left">
</div><p style="text-align:center">&quot;<b>Most good programmers do programming not because they expect to get 
paid or get adulation by the public, but because it is fun to program.</b>&quot; <br></p><p style="text-align:center">Linus Torvalds</p>
</blockquote><br>
</div></div></div>