Noob question, when using xml zippers, is there a way to create programmatically a root node? Can't seem to find one

I tried: (data-xml/element :root {} (map zip/node (dzx/xml-> family-loc :resource)))

but no luck

https://clojuredocs.org/clojure.zip/xml-zip

(xml-zip root) Returns a zipper for xml elements (as from xml/parse), given a root element

does that not work?

no I mean, I have already the bits and pieces from the zippers, I want to combine stuff together, but I need a root

oh you have a forest of nodes?

and need to combine them?

yep I am trying now -> (zip/make-node family-loc (dx/element :root {} {}) (dzx/xml-> family-loc :resource))

the above makes it almost right, if only there was only one contect vector and not a vec of vec

(apply data-xml/element :root {} (map (.....))?

aaaand....the winner is: (zip/make-node family-loc (dx/element :root) (map zip/node (dzx/xml-> family-loc :resource)))

why doesn't this work:

(let [func #(println "raboof")
      jb   (defrecord Foo []
             org.quartz.Job
             (execute [_ _] (func)))]
... ;stuff
)
=> CompilerException java.lang.RuntimeException: Unable to resolve symbol: func in this context, compiling:(/tmp/form-init7561963032470631764.clj:4:29) 

why do I see here

(s/with-gen get-objectNumbers
 (fn [] (gen/sample (gen '/string-from-regex #"[A-Z]{2}-[A-Z]-\d{1,4}")))) 

this message : Unmatched delimiter: )

I checked several times and all the ) seems to match

@vandr0iy maybe because defrecord generate class and must be compiled before func appears. you can try reify instead of defrecord

'/string-from-regex <- typo?

@delaguardo unfortunately, that's not an option - quartz, in order to schedule a task, must define a class that implements the org.quartz.Job interface with the stuff to do to be placed in the execute method; then, whenever it wants to schedule that job it extends that class... friggin Java """""design patterns"""""

@vandr0iy thanks

I was a typo and a forgotten namespace import

I have this spec : (s/def ::objectNumber (s/and string? #(re-matches #"[A-Z]{2}-[A-Z]-\d{1,4}" %)))

and this generator :

(s/with-gen ::objectNumber
 (fn [] (gen/sample (gen'/string-from-regex #"[A-Z]{2}-[A-Z]-\d{1,4}"))))  

which produces this output :

[clojure.spec$and_spec_impl$reify__13956 
 17955548 
 "clojure.spec$and_spec_impl$reify__13956@111fadc"]  

which looks good to me

but when I do : (s/exercise ::objectNumber)

I see this output : ExceptionInfo Couldn't satisfy such-that predicate after 100 tries

Can someone give me a hint what is going wrong ?

@roelofw the generator is randomly producing strings and then checking that they conform to your spec. Given enough time it would generate some that do but it gives up after 100 tries. You need to write a custom generator for that spec as it's too specific for the generic one to cope with. Try reading this: http://clojure.org/guides/spec#_custom_generators

BTW scroll up from that heading in the page and you will see an example of a similar exception and an explanation of why it happened.

yep, that is why I tried to write a custom generator with the help of test.chuck

so my custom generator is not doing what its supposed to do

back to that part and read it another time

Haven't used test.chuck so I suggest you read the readme and try some very simple examples first. Might give you a clue. Always start by simplifying the problem and take it step at a time.

oke, I will, I checked the anymous function and that one worked fine

so I think I did something wrong with the with-gen part

seancorfield said I have to use this template : (s/with-gen my-spec (fn [] the-generator)) `

I think my-spec is here : ::objectNumber

and the generator schould be (gen/sample (gen'/string-from-regex #"([A-Z]{2}-[A-Z]-\d{1,4})"))

back to the manual

last question

I have this

(s/def ::objectNumber2
 (s/with-gen ::objectNumber
  (fn [] (gen/sample (gen'/string-from-regex #"([A-Z]{2}-[A-Z]-\d{1,4})"))))) 

is now ::objectNumber2 the name of the generator ?

I'm keeping a registry of processes in an atom. However, you're not supposed to perform side-effects in a swap!, so this code is no good:

(swap! processes #(if (get % id) % (assoc % id (create-process! id))))

When I do (s/exercise ::objectNumber) or (s/exercise ::objectNumber2) I see this message : AssertionError Assert failed: Second arg to such-that must be a generator

so I wonder what is here the name of the generator :

(s/def ::objectNumber2
 (s/with-gen ::objectNumber
  (fn [] (gen/sample (gen'/string-from-regex #"([A-Z]{2}-[A-Z]-\d{1,4})"))))) 

I suspect ::objectNumber2 but that one also error out

@magnars what do you want to do exactly ?

@roelof I want to start one and only one process (specifically a core.async go-loop) per id.

@magnars maybe start with the if then ?

Moving the if outside the swap! would only add another race condition to the mix.

hmm, then I have at this moment, no idea

Thanks for giving it some thought anyways. 🙂

YW

@roelof gen/sample takes a generator and returns some samples generated from it. It does not return a generator. The anonymous fn needs to return a generator.

oke, back to the manual how to do that

@madstap any tips/hints

I think I missed this part : #(s/gen ?

@roelof hint: gen'/string-from-regex does return a generator

@roelof "I think I missed this part : #(s/gen ?" No, s/gen is for getting a generator from a spec. You already have the generator from the call to string-from-regex.

Thanks for the tip. This is working :

(s/def ::objectNumber
 (s/with-gen ::objectNumber
  (fn [] (gen'/string-from-regex #"([A-Z]{2}-[A-Z]-\d{1,4})")))) 

the custom generator should not use sample

(sorry, reading backchat out of order - looks like you’re there)

another problem : when I do (s/explain :artObject/response (get-data-detail-page ( get-artObject ( read-json-data "SK-C-5" )))

I see this error : RuntimeException EOF while reading, starting at line 1

I tried this (get-data-detail-page ( get-artObject ( read-json-data "SK-C-5" )))

and that worked fine

That first snippet is missing a closing paren

@roelof ^

thanks, I overlooked it when I was checking that one

@magnars Here's an idea for how you can accomplish what you want: 1. Try to add the process id to processes with a unique number as value. 2. Outside the swap!, create the process, if the process id was added. 3. Exchange the random number with the result from create-process!.

Can I make a spec that I want to have a number between let's say 1900 - 2017 ?

@henriklundahl: thanks, that sounds like it would work. 👍

@roelof: (s/int-in 1900 2018)

he, I thought you were not on slack this weekend

with a little help I got the generator works for objectNumber and most of the specs

@belucid : how is the show going ? I know this is offtopic

@seancorfield how is the show going ? I know this is offtopic

I'm not at my computer. On my phone. Short replies. Show starts in a few hours, 100 miles from home 😸

oke, success and I take care that on Monday my github is up-to-date

Alright I’ve got a silly question

Trying to open package manager with M-x by pressing command + x

(in Emacs)

Taking me to the last character of my buffer but not opening the command window as I would hope

M-x is option-x or alt-x (on Mac). The command-x key is S-x in Emacs speak.

Turns out it’s the option key 😁

@seancorfield thank you sir!

I have made this function

(s/fdef get-objectNumbers
 :args (s/cat :response :artObject/response)
 :ret (s/coll-of ::objectNumber)) 

and made this generator :

(s/def ::objectNumber
 (s/with-gen ::objectNumber
  (fn [] (gen'/string-from-regex #"([A-Z]{2}-[A-Z]-\d{1,4})")))) 

now I want to test it so I did : (stest/check 'get-objectNumbers)

but then I see this as output ()

when I do this : (stest/check ::objectNumber)

I get as message : IllegalArgumentException Don't know how to create ISeq from: clojure.lang.Keyword

Can anyone give me a hint which part I do not understand of the clojure spec guide

stest/check works on "vars (functions) named by symbols" which is why that second call fails — ::objectNumber is a keyword, not a symbol.

Try

(stest/check `get-objectNumbers)

(stest/check ‘paintings2.api-get/get-objectNumbers)

(don’t forget to keep your GitHub repo up-to-date @roelof so folks can always see your latest code, when you need help)

the first one gives this as answer :

({:clojure.spec.test.check/ret {:num-tests 1000, 
                                :seed 1483727820434, 
                                :result true}, 
  :sym paintings2.api-get/get-objectNumbers, 
  :spec [clojure.spec$fspec_impl$reify__14282 
         7640208 
         "clojure.spec$fspec_impl$reify__14282@749490"]})   

which seems good

the second one gives almost the same :

({:clojure.spec.test.check/ret {:num-tests 1000, 
                                :seed 1483727903786, 
                                :result true}, 
  :sym paintings2.api-get/get-objectNumbers, 
  :spec [clojure.spec$fspec_impl$reify__14282 
         7640208 
         "clojure.spec$fspec_impl$reify__14282@749490"]})  

:thumbsup::skin-tone-2: Often easiest to call (stest/summarize-results (stest/check ‘my-ns/my-fn)) to get sane results back. Failures produce very large output otherwise.

For example:

user=> (require '[clojure.spec :as s])
nil
user=> (require '[clojure.spec.test :as stest])
nil
user=> (defn foo [n] (inc n))
#'user/foo
user=> (s/fdef foo :args (s/cat :n int?) :ret int?)
user/foo
user=> (stest/summarize-results (stest/check 'user/foo))
{:sym user/foo}
{:total 1, :check-passed 1}
user=> (defn foo [n] "Boom!")
#'user/foo
user=> (s/fdef foo :args (s/cat :n int?) :ret int?)
user/foo
user=> (stest/summarize-results (stest/check 'user/foo))
{:spec (fspec :args (cat :n int?) :ret int? :fn nil),
 :sym user/foo,
 :failure
 {:clojure.spec/problems
  [{:path [:ret], :pred int?, :val "Boom!", :via [], :in []}],
  :clojure.spec.test/args (0),
  :clojure.spec.test/val "Boom!",
  :clojure.spec/failure :check-failed}}
{:total 1, :check-failed 1}

@seancorfield thanks, that produces this : {:check-passed 1, :total 1}

so it seems my get-objectNumbers works well

my first test written in spec 🙂

Does this :num-tests 1000, means there are 1000 tests done

then the test are very fast

Yes, for small, simple functions, generative testing is pretty quick.

Behind the scenes, it is generating 1,000 pieces of data that conforms to the :args spec and then calling the function for each piece, and then verifying the :ret (and :fn) spec.

(this is part of clojure.test.check behind the scenes — adapted from Haskell’s QuickCheck — and the real power behind clojure.spec for testing)

thanks for the explanation. That was one of the things I liked about haskell QuickCheck

This weekend I can now write the last fdef and test everything 🙂

and then think about how to make it work. I see a pagination with page-numbers

and my first project is done 🙂

Is it normal with proto-repl that it takes multiple minutes to get in a state where I can work on it

I have this file ( https://github.com/rwobben/paintings/blob/master/src/clj/paintings2/api_get.clj ) in my project and if I start up repl it looks like proto-repl is not responding at all

This is happening since I added a spec test

Sounds like you still have some of the “reload” options enabled?

See ProtoREPL > Settings https://www.dropbox.com/s/zzarlw8z1qlhqxx/Screenshot%202017-01-06%2011.46.06.png?dl=0

I have these all disabled

I just checked it

Whats the recommended way of actually using your function specs. Do you just use instrument? Is there a way to actually check the :fn and :ret portions, or is there something else?

I use instrument to test the input parameters , this uses only the :args part

after that I write the rest and use (stest/summarize-results (stest/check namespace/function)) to test if the function does what I expect. Herefore I only use the :args` and :ret part because I have very small functions

how would you specify that both arguments are both extend a protocol, and have the same type just using :args

@adamkowalski I hope this makes something clear for you

like if I want to write an append function, that can work with two vectors, lists, sets, or hash maps

but I want them to be the same type

pairs of vecs, etc...

That question I cannot help you, Im also learning spec and tests

I guess I could put it as a precondition right? just say that they must have the same type

I think you can put that in the fn . but I can be mistaken as I said earlier im also learning specs and spec testing

I hope some more experienced person in spec can answer that

im sorry I cannot help you more

(s/fdef append
        :args (s/cat :a coll? :b coll?)
        :fn (fn [{:keys [args ret]}]
              (let [{:keys [a b]} args]
                (= (type a) (type b) (type ret))))
        :ret coll?)

thats what I was thinking

but instrument doesn’t seem to check either fn or ret

correct, as far as I know instrument looks only at the `:args

instrument is as far as I know be used to check if the right parameters are used

@adamkowalski to specify a relationship between args, just s/and an additional predicate to the :args spec

like (s/fdef append :args (s/and (s/cat :a coll? :b coll?) (fn [{:keys [a b]}] (= (type a) (type b)))))

if you want to specify a relationship between args and ret, then that needs to be in :fn

putting it in :args has the benefit of being checked by instrument

oh yeah that makes things a lot easier

thanks for the tip

I have another question however

Could specs potentially replace protocols? Or I mean, can they provide the same functionality that they can provide?

Instead of specifying that something extends a protocol, could you just continually compose specs and accomplish something similar

@alexmiller Are you a atom user ?

why does this throw an exception? (def c (chan 10)) (>!! c 20) (alts!! [(timeout 2000) c])

. Unhandled java.lang.NoSuchMethodError clojure.core.async$do_alts$fn__12286.<init>(Ljava/lang/Object;Ljava/lang/Object;ILjava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)V

@roelof no

@rgorrepati I can’t repro that - I get [20 #object[clojure.core.async.impl.channels.ManyToManyChannel 0x2026efb8 “clojure.core.async.impl.channels.ManyToManyChannel@2026efb8”]] - a value and the channel c

@alexmiller Interesting..

@alexmiller sorry, may be something weird with my nrepl