This is a late reply to my own question but maybe it will be helpful to a future searcher.
http://blog.cognitect.com/blog/2016/10/5/interactive-development-with-clojurespec has an example that showed me more clearly how to use :fn. Specifically here's how I rewrote the spec: (s/fdef mapper :args (s/cat :t :fake.flowrs-tests/positive-integer? :b :fake.flowrs-tests/positive-integer?) :ret map? :fn (fn [{args :args ret :ret}] (= (:tacos ret) (vec (range (:t args)))) (= (:burritos ret) (vec (range (:b args)))))) (s/exercise-fn `mapper) has the same behavior as before -- it exercises the *implementation* of the function. But (stest/check `mapper) will return "Specification-based check failed" etc. when the implementation of mapper doesn't match. As for the other part of the question: turning the logical test of :fn into a function that can be run to generate the result, that would require quite a bit of code rewriting. A partial step is just to extract the :fn part of the code, and that can be done as follows: (:fn (apply hash-map (rest (s/form (get (s/registry) 'fake.flowrs/mapper))))) ;=> (clojure.core/fn [{args :args, ret :ret}] (clojure.core/= (:tacos ret) (clojure.core/vec (clojure.core/range (:t args)))) (clojure.core/= (:burritos ret) (clojure.core/vec (clojure.core/range (:b args))))) The function so-obtained can be evaluated, but it won't "do" the job of the mapper function without further code transformation. I'll leave it at that for now. -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
