randomly-fn reads the commands first (that's why you need a macro in the
first place) so it prints 1 2 and 3 straight away. If you really need a
function, use lambdas (as in #(print 1) #(print 2) #(print 3))

2012/5/2 金山 <si262...@gmail.com>

> I defined a macro like this:
> (defmacro randomly [& exprs]
>  (let [len (count exprs)
>        ind (rand-int len)
>        conditions (map #(list '= ind %) (range len))]
>    `(cond ~@(interleave conditions exprs))))
>
> and then defined a function :
> (defn randomly-fn [& exprs]
>     (randomly exprs))
>
> I think there may be a mistake because of the randomly-fn didn't work
> as expected.
>
> (randomly-fn (print 1) (print 2) (print 3))
>
> expected:
> 1 or 2 or 3.
> but returned:
> 123
>
> where is the mistake?
>
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