I&#39;ve briefly gone through the Ur demo at <a href="http://impredicative.com/ur/demo/">http://impredicative.com/ur/demo/</a><div><br></div><div>Ur looks very impressive, so the natural question I&#39;m asking myself is:  How does it stack up against haskell frameworks, and why can&#39;t Ur be implemented in Haskell?  </div>

<div><br></div><div>I&#39;m thinking mainly of the safety guarantees, not necessarily the performance guarantees, GC-less execution, or even non-lazy evaluation.</div><div><br></div><div>And I can&#39;t answer those.. any takers?</div>

<div><br></div><div>Alexander</div>