So it seconds my initial point: you can&#39;t store the size because it has no sense.<br><br><div class="gmail_quote">2011/5/25 Ketil Malde <span dir="ltr">&lt;<a href="mailto:ketil@malde.org">ketil@malde.org</a>&gt;</span><br>

<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div class="im">&quot;Richard O&#39;Keefe&quot; &lt;<a href="mailto:ok@cs.otago.ac.nz">ok@cs.otago.ac.nz</a>&gt; writes:<br>


<br>
&gt;&gt; Then tell me, why does calculating the length of a (Haskell)<br>
&gt;&gt; list has O(n) complexity.<br>
<br>
&gt; Because it is a rather rare operation and the cost of doing<br>
&gt; this would be far higher than you think.<br>
<br>
</div>I suspect that if you store the length non-strictly, it would build up<br>
thunks, causing a stack overflow when evaluated.  If it is strict, it<br>
would make a lot of operations that are O(1) today into O(n) operations.<br>
<div class="im"><br>
-k<br>
--<br>
If I haven&#39;t seen further, it is by standing in the footprints of giants<br>
<br>
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