Hi Alex, I could track down why explain stops
early. http://dev.clojure.org/jira/browse/CLJ-2013
On Wednesday, August 24, 2016 at 11:33:43 PM UTC+2, Leon Grapenthin wrote:
>
>
> On Tuesday, August 23, 2016 at 3:27:28 AM UTC+2, Alex Miller wrote:
>>
>> predicate: (cat :args (* :clojure.core.specs/binding-form) :varargs (?
>> (cat :amp #{(quote &)} :form :clojure.core.specs/binding-form))),
>>
>> the predicate that is actually failing in the spec, probably not
>> particularly helpful given the complexity (and recursiveness) of the
>> destructuring specs
>>
>>
>> Extra input
>>
>> this is the part of cat that I think could be made more explicit - could
>> be saying here that the value it had (above) was expected to match the next
>> part of the cat (binding-form). So that could say the equivalent of
>> "Expected binding-form but had non-matching value ..." and could even find
>> what parts of that value matched and maybe which didn't (the :or keys) such
>> that you'd have a more precise description. There is some more stuff Rich
>> and I have worked on around "hybrid maps" which is the case here with map
>> destructuring - it's particularly challenging to get a good error out of
>> that at the moment, but there's more that can be done.
>>
>>
> Thank you for doing the walkthrough. I observed this too and became
> sceptical why spec doesn't go further down the path and apparently stops at
> ::binding-form.
> I could isolate the problem a bit by changing the spec of ::arg-list and
> temporarily removing the :varargs branch.
>
> (s/def ::arg-list
> (s/and
> vector?
> (s/cat :args (s/* ::binding-form)
> ;; :varargs (s/? (s/cat :amp #{'&} :form ::binding-form))
> )))
>
> This leads to a much better message:
>
> (s/explain (:args (s/get-spec 'clojure.core/defn))
> '[foo [{:or {a/b 42}}]])
>
> In: [1 0] val: {:or #:a{b 42}} fails spec: :clojure.core.specs/local-name
> at: [:bs :arity-1 :args :args :sym] predicate: simple-symbol?
> In: [1 0 0] val: ([:or #:a{b 42}]) fails spec:
> :clojure.core.specs/seq-binding-form at: [:bs :arity-1 :args :args :seq]
> predicate: (cat :elems (* :clojure.core.specs/binding-form) :rest (? (cat
> :amp #{(quote &)} :form :clojure.core.specs/binding-form)) :as (? (cat :as
> #{:as} :sym :clojure.core.specs/local-name))), Extra input
> In: [1 0 :or a/b 0] val: a/b fails spec: :clojure.core.specs/or at: [:bs
> :arity-1 :args :args :map :or 0] predicate: simple-symbol?
> In: [1 0] val: {:or #:a{b 42}} fails spec: :clojure.core.specs/arg-list
> at: [:bs :arity-n :bodies :args] predicate: vector?
>
> The third one is the desired one and very precise - it seems to be usually
> the one with the largest :in path. The length of the :in path seems a good
> sorting criterium for reporting.
>
> However I was not able to track the issue further down. I also wasn't able
> to reproduce a more minimal case of this problem. It seems like a bug in
> how spec parses and must have something to do with s/cat and the :varargs
> branch.
>
--
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.
