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copied!<p>Monads and Macros operate at different levels of abstraction. </p> <p>I think of macros as "code monkeys": anytime I find myself writing a lot of boilerplate, I take a moment and think whether macros can help.</p> <p>Monads on the other hand are very powerful abstractions generally used in order to isolate and compose side effects in a purely functional setting. (I'm not an expert on Monads so take this with a grain of salt).</p> <p>The bottom line is that I think they are solving fundamentally different problems.</p> <p>If we take the example you provided, writing a Redis driver, any function accessing the network is a candidate for an abstraction through monads - in this case, both the IO and Maybe (or Either) monads. But not because of repetition, but rather because your functions have side effects.</p> <p>Now this is where Monads in clojure can get harder than it's worth: If you want to compose both monads, you need to use <a href="http://en.wikibooks.org/wiki/Haskell/Monad_transformers" rel="nofollow">monad transformers</a>. Obviously this is not enforced by clojure since it's a dynamic language so one can argue debugging composed monadic code in a dynamic language can be very hard. A static type system such as Haskell's would be of great help here.</p> <p>So while a redis driver can definitely be written in a monadic style, I believe the point Aaron is making in the presentation is avoiding repetition, and for that, I believe macros are a better fit in Clojure.</p> <p>I hope this is helpful.</p> <p><strong>EDIT</strong>:</p> <p>I should also node that monads in Clojure would be hardly useful without the Haskell inspired <em>do</em> notation which is essentially made possible by macros, providing further proof that macros are at a different level of abstraction. </p>

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