Given any functor you can get a monad for free! <div><br></div><div>data Free f a = Either a (f (Free f a))</div><div><br></div><div>Not sure about unfree, but there are cofree comonads that are pretty closely related, and give you a comonad given a functor:</div>
<div><br></div><div>data Cofree f a = (a, f (Cofree f a))<br><div><br></div><div>I'm sure the more categorically minded can tell you way more.</div><div><br></div><div>Hope this helps,</div><div>Dan</div><div><br><div class="gmail_quote">
2010/2/27 Günther Schmidt <span dir="ltr"><<a href="mailto:gue.schmidt@web.de">gue.schmidt@web.de</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Hello,<br>
<br>
I see the term "free monad" quite a lot, but don't really see an explanation what a free monad is. What sets a monad free and why in this day and age are there unfree monads?<br>
<br>
Günther<br>
<br>
<br>
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