Just had a chance to play around with spec. Looks like this is going to destroy a lot of problem space :) Thanks.
Probably a bug: (s/exercise (s/and set? (s/coll-of (s/with-gen keyword? #(gen/elements [:s1 :s2 :s3])) #{}))) ;-> ([#{} #{}] [#{} #{}] [#{} #{}] [#{:o-85:1ywl} #{:o-85:1ywl}] [#{} #{}] [#{} #{}] [#{} #{}] [#{:_Qi.Qj?dtMZh_s*3.x.sTxm9-E.NHr!?b5f0Ir2.u.+bof*-P.r.m_y**e0ntq.W+*.+?Urxe+Xp+/Q} #{:_Qi.Qj?dtMZh_s*3.x.sTxm9-E.NHr!?b5f0Ir2.u.+bof*-P.r.m_y**e0ntq.W+*.+?Urxe+Xp+/Q}] [#{} #{}] [#{} #{}]) Reverse argument order to s/and and it works. On Monday, May 23, 2016 at 4:12:29 PM UTC+2, Rich Hickey wrote: > > Introducing clojure.spec > > I'm happy to introduce today clojure.spec, a new core library and support > for data and function specifications in Clojure. > > Better communication > > Clojure is a dynamic language, and thus far we have relied on > documentation or external libraries to explain the use and behavior of > functions and libraries. But documentation is difficult to produce, is > frequently not maintained, cannot be automatically checked and varies > greatly in quality. Specs are expressive and precise. Including spec in > Clojure creates a lingua franca with which we can state how our programs > work and how to use them. > > More leverage and power > > A key advantage of specifications over documentation is the leverage they > provide. In particular, specs can be utilized by programs in ways that docs > cannot. Defining specs takes effort, and spec aims to maximize the return > you get from making that effort. spec gives you tools for leveraging specs > in documentation, validation, error reporting, destructuring, > instrumentation, test-data generation and generative testing. > > Improved developer experience > > Error messages from macros are a perennial challenge for new (and > experienced) users of Clojure. specs can be used to conform data in macros > instead of using a custom parser. And Clojure's macro expansion will > automatically use specs, when present, to explain errors to users. This > should result in a greatly improved experience for users when errors occur. > > More robust software > > Clojure has always been about simplifying the development of robust > software. In all languages, dynamic or not, tests are essential to quality > - too many critical properties are not captured by common type systems. > spec has been designed from the ground up to directly support generative > testing via test.check https://github.com/clojure/test.check. When you > use spec you get generative tests for free. > > Taken together, I think the features of spec demonstrate the ongoing > advantages of a powerful dynamic language like Clojure for building robust > software - superior expressivity, instrumentation-enhanced REPL-driven > development, sophisticated testing and more flexible systems. I encourage > you to read the spec rationale and overview http://clojure.org/about/spec. > Look for spec's inclusion in the next alpha release of Clojure, within a > day or so. > > Note that spec is still alpha, and some details are likely to change. > Feedback welcome. > > I hope you find spec useful and powerful! > > Rich > > -- 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.