To further clarify, you can and should turn on spec’s instrumentation *during testing* (and interactive development) to get contract-system style inter-function call checking. To the extent those tests are themselves generative (e.g. spec’s) the coverage and ranges will be good.
As to whether an fn-returning function, *when instrumented*, should return instrumentation-wrapped fns, I don’t know. I’d be concerned about tracking them lest you can never unstrument them. > On May 25, 2016, at 5:57 PM, Rich Hickey <richhic...@gmail.com> wrote: > > In my mind, fspec is no different than fdef. > > With fdef you specify what a function does. How do we know it works? - > generative testing. Wrappers only check individual calls. > > Now you say your function returns a fn, and provides an fspec (same as fdef, > a trio of specs) for that. How do we know the returned fn (which is often > implemented anonymously, not a named thing we could fdef) works? It’s not a > different question so it has the same answer - generative testing. > > spec is about making sure your programs _work_ *ahead of time* by using > generative testing, and leaving only application-domain required checks > active at runtime (i.e. checking your program would otherwise do manually). > > Contracts are about making sure your _broken programs fail_ as soon as > possible at *(production?) runtime*, and do so at considerable runtime cost. > If you only activate them during testing then quality depends the coverage > and ranges of your test suite (usually poor). > > spec is not a contract system. > > Rich > >> On May 25, 2016, at 4:05 PM, Ambrose Bonnaire-Sergeant >> <abonnaireserge...@gmail.com> wrote: >> >> Rich, >> >> Can you talk about the design process behind fspec? >> >> What tradeoffs were in mind for fspec performing gen testing rather >> than a traditional function contract wrapper a la racket/contract? >> >> Thanks, >> Ambrose >> >> On Mon, May 23, 2016 at 5:20 PM, Rich Hickey <richhic...@gmail.com> wrote: >> I did most of the design of spec in a (paper) notebook. >> >> The rationale tries to capture the salient driving forces. >> >> If there is a specific question you have I’d be happy to answer. >> >> Rich >> >>> On May 23, 2016, at 4:11 PM, Ivan Reese <ivanre...@gmail.com> wrote: >>> >>> Is there anywhere we can read anything about the design process behind >>> clojure.spec? I took a look at dev.clojure.org / JIRA, but I haven't yet >>> found anything on the topic. >>> >>> -- >>> 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. >> >> -- >> 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. >> >> >> -- >> 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. > -- 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.
