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.
