http://dev.clojure.org/jira This file is an XML representation of an issue en-us 4.4 649 25-07-2011 http://dev.clojure.org/jira/browse/ALGOM-7 algo.monads <p>One of the monad laws is that (m-bind (m-result v) f) should be the same as (f v). However, this is not the case in maybe-m:</p> <p>user=&gt; (with-monad maybe-m (m-bind (m-result nil) nil?))<br/> nil</p> <p>user=&gt; (nil? nil)<br/> true</p> <p>The crux of the problem is that in algo.monad's maybe-m, there is no way to wrap a nil in a Just-like container.</p> ALGOM-7

maybe-m breaks the monad laws.

Defect Major Open Unresolved Konrad Hinsen Seth J. Gold Sat, 15 Sep 2012 15:00:36 -0500 Sat, 15 Sep 2012 15:27:03 -0500 0 2 <p>Just realized that that demonstration doesn't actually work, because the function passed to m-bind is supposed to return a monadic value. Here's a better one:</p> <p>user=&gt; (with-monad maybe-m (m-bind (m-result nil) (comp m-result nil?)))<br/> nil<br/> user=&gt; (with-monad maybe-m ((comp m-result nil?) nil))<br/> true</p> Global Rank