Hi Oleg,<br><br><div class="gmail_quote">On Tue, Jun 21, 2011 at 09:35,  <span dir="ltr">&lt;<a href="mailto:oleg@okmij.org">oleg@okmij.org</a>&gt;</span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">

<br>
I have implemented type-level TYPEREP (along with a small library for<br>
higher-order functional programming at the type level).  Overlapping<br>
instances may indeed be avoided. The library does not use functional<br>
dependencies either.<br>
<br>
        <a href="http://okmij.org/ftp/Haskell/TTypeable/" target="_blank">http://okmij.org/ftp/Haskell/TTypeable/</a><br></blockquote><div><br>At a first glance, I think your TYPEOF encodes less information about types than the new generics Rep. By &quot;less&quot; I mean that one could get that information from Rep (which is derived automatically).<br>

<br>Our generics do not, however, encode a type-level natural per type. This greatly simplifies type-level type equality. But I am still doubtful of the runtime performance of your code; also, the 
need to define a duplicate of the class (MonadState&#39; in your example) 
bloats the code significantly.<br><br><br>Cheers,<br>Pedro<br></div></div><br>