Hey folks, can you help me to understand why I can't gen/generateor gen/sample:

(def email-regex #"^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,63}$")

(spec/def ::email-type (spec/and string? #(re-matches email-regex %)))
(spec/def ::uuid int?)
(spec/def ::first-name string?)
(spec/def ::last-name string?)
(spec/def ::email ::email-type)
(spec/def ::phone #"^\d{12}$")

(spec/def ::person (spec/keys :req [::first-name ::last-name ::email]
                              :opt [::phone]))
(gen/generate (spec/gen ::person))

Error: 
 Show: Project-Only All 
  Hide: Clojure Java REPL Tooling Duplicates  (13 frames hidden)

1. Unhandled clojure.lang.ExceptionInfo
   Couldn't satisfy such-that predicate after 100 tries.
   {:pred #function[clojure.spec.alpha/gensub/fn--1876],
    :gen
    {:gen #function[clojure.test.check.generators/such-that/fn--40141]},
    :max-tries 100}

Have you tried exercising your specs?

Couldn't satisfy such-that predicate after 100 tries

Thats the key part to the error message

I would just go through each def and see if they can produce a result

my bet is on email and phone

yes i would agree

If the predicate is too hard to er fufill? based on random string input, don't you usually just create a generator for those complicated predicates?

also i'm not all that sure how (spec/def ::phone #"^\d{12}$") works

If you exercised ::phone what would you get? thats a pattern isnt it :thinking_face:

Unable to construct gen at: []

Thats what i get

for (s/exercise ::phone)

Just saw now, the answers, will be right back after doing what you said 😄

So then I think for the email, its just as simple as, the string generator can't create a random entry that matches your regex

which makes sense right? as even after 100 times its going to be difficult to randomly create an email i think haha

https://clojure.org/guides/spec#_custom_generators

After trying to exercise each attribute, it appears that ::phone and ::email-type can't be exercised

@quieterkali Use https://clojuredocs.org/clojure.spec.alpha/with-gen to provide alternative generators

https://github.com/gfredericks/test.chuck has a generator for regex strings that I've found very useful.

I am trialling offloading some extra logic onto s/or and would like some collective opinion, if y'all were so kind. Suppose I have a spec defined like this:

(s/or :x :x/item
      :y :y/item)

(s/or [:additive :x] :x/item
      [:additive :x1] :x1/item
      [:multiplicative :y] :y/item)

(s/or {:type :additive
       :operand-type :x
       :precedence 1}
      :x/item

      {:type :additive
       :operand-type :x1
       :precedence 2}
      :x1/item

      {:type :multiplicative
       :operand-type :y}
      :y/item)