Hi everyone,
I'm working my way through Practical Clojure's macro chapter, and I'd like
to check my understanding about one of the examples.
The book discusses writing a macro to randomly evaluate a form out of a list
of forms--essentially a cond that randomly selects which branch to evaluate.
The book's version looks like this:
(defmacro rand-expr-multi [& exprs]
`(let [ct# ~(count exprs)]
(case (rand-int ct#)
~@(interleave (range (count exprs)) exprs))))
My version looks like this:
(defmacro rand-expr-mulit [& exprs]
(let [n (rand-int (count exprs))]
(nth exprs n)))
Is there any difference between the two? I'm a little shaky on macro
expansion-time vs run-time, hygiene, etc.
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