Incidentally (and more as a curiosity than anything else)<div><div><br></div><div>Prelude&gt; :t uncurry . flip . curry $ id</div><div>uncurry . flip . curry $ id :: (b, a) -&gt; (a, b)</div><br><div class="gmail_quote">On Wed, Jul 7, 2010 at 1:54 PM, Yitzchak Gale <span dir="ltr">&lt;<a href="mailto:gale@sefer.org">gale@sefer.org</a>&gt;</span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Patrick LeBoutillier wrote:<br>
&gt; is there... perhaps a builtin function to flip a pair:<br>
&gt;  (a, b) -&gt; (b, a)<br>
<br>
The function<br>
<br>
swap (x, y) = (y, x)<br>
<br>
will be added to Data.Tuple in the next release<br>
of the base libraries. In the meantime, it is easy<br>
enough to define it yourself, and then, of course<br>
<br>
rlookup x = lookup x . map swap<br>
<br>
Or, you could use the find function from Data.List<br>
and write:<br>
<br>
rlookup x = find ((== x) . snd)<br>
<br>
Regards,<br>
Yitz<br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>          Alex R<br>
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