hey guys, quick question: what is the clojure/spec.alpha project in github? is it an old version of clojure.spec?

I think it's the new version

yes, the fact that the readme mentions nothing about what it is doesn't help tbh (or how to use it; you have to dig into the google group announcement instead)

wait what! so if I update my version of Clojure then it would break 😞 ?

is it also like that for Cljs?

yes, you need to update your require calls and potentially clj.spec/invalid kw

dunno about cljs, but I guess so

This problem had me spinning for close to an hour

wasted quite some time on it too, even tho I knew what to do

is it possible to use spec to ensure that one spec'ed key in a map containing a number is larger than the value another spec'ed key?

starting with something like this:

(s/def :my.app/start int?)
(s/def :my.app/end int?)

(s/def :my.app/timer
  (s/keys :req [:my.app/start :my.app/end]))

Yes, you can do something like

(s/def :my.app/timer
  (s/and (s/keys :req [:my.app/start :my.app/end])
         #(<= (:my.app/start %) (:my.app/end %))))

thanks. that makes perfect sense.

s/def takes a keyword and a predicate (or composite of them)

Yeah, the 2nd arg is a spec, which can be specs from the spec namespace, sets, or really any function that returns truthy/falsey, or any combination.

The docs say spec, spec-name, predicate or regex-op

i got as far as Usage: (def k spec-form) and didn't bother to read down 😉

this is probably a dumb question, but when exercising a spec with a custom function (such as the <= above), is clojure generating ints at random and then only filtering out results that pass the spec? or is it truly generating valid specs on the first try?

in other words, how hard is it working to exercise the spec?

s/and uses the first spec as a generator, and the following specs as filters

as far as I remember

If you want something more intelligent, you'd have to provide the generator yourself

gotcha, thanks again

np

is the plan to move clojure.spec.alpha back to just clojure.spec after it's released?

I might just park at the version of clojure 1.9 I'm using until it goes back

https://groups.google.com/forum/#!msg/clojure/10dbF7w2IQo/ec37TzP5AQAJ <- @mattly, seems that the plan is to move back to a non-alpha namespace after

It is likely that 1.9 will release before spec is finalized (that is, 1.9 final will depend on clojure.spec.alpha). Being able to do so is the main reason we did the split.

ok, thanks

can someone help me understand why this is producing a vector of vectors rather than a single collection of numbers?

(s/def :test/coll (s/coll-of number?))
(s/exercise :test/coll)
=> ([[-2.0 -1 0 -2.0 -2.0 1.0 0 0.5 0 0 -0.5 -2.0 0.5 -0.5] [-2.0 -1 0 -2.0 -2.0 1.0 0 0.5 0 0 -0.5 -2.0 0.5 -0.5]]
     [[0 0 -3.0 -1 0 -1 -1 -0.75 -1 -1 0 -1 -2.0]...]

i would have expected just a list of collections

me too

i also get some NaNs

[[0 -4.0 0 26 1 -1.25 NaN] [0 -4.0 0 26 1 -1.25 NaN]]

does NaN pass number?

i don't even know how you'd represent NaN in clj...

it's an instance of Double

but i'm still more confused about the deeply nested collections

ah

read the docstring for s/exercise

it's not a coincidence that you have pairs of identical collections

pairs of generated and conformed values for a spec ahhh

it's generating ten collections of things satisfying number?, right?

@joshkh exercise generates values, and conforms them, then returns a collection of those pairs

you can also (gen/sample :test/coll) to just get the samples

that's the second time i've stared right past the docs today. time for a coffee. thanks guys.

or (map first (s/exercise :test/coll))

@mpenet I updated the spec.alpha readme a little

It's not pushed yet, right?

it is pushed

https://github.com/clojure/spec.alpha/blob/master/README.md

I was looking at core.specs.alpha :D mixed the two. I guess it might get a readme update as well there

oh, yeah. will do

A lot better, thanks

certainly better than nothing! I meant to come back to those, just forgot to do so after the release.