clojure.spec/keys requires input collections conform to clojure.core/map?

Question

I would like to use specs to validate Datomic entities. However, s/keys is too restrictive in that it requires input collections to conform to clojure.core/map? instead of some more primitive interface (for example clojure.lang.ILookup or clojure.lang.Associative).

Answer 1

Comment made by: alexmiller

s/keys uses IPersistentMap's Iterable support for iterating through all entries for validation. ILookup and Associative do not support iteration. So, that's why it is the way it is. But, understand the desire.

Answer 2

Comment made by: alexmiller

Datomic entities are seqable so maybe that's a potential path (would be slower for actual PHMs though).

Answer 3

Comment made by: odinodin

Thanks for following up. So any ideas or guidance on how to use clojure.spec with Datomic entities?

Answer 4

Comment made by: alexmiller

For now, you could use into to pour an entity into a PHM before validating. I hesitate to suggest it, but that could even be in the spec with a leading conformer.

Answer 5

Comment made by: alexmiller

Moving this into 1.9 for the moment just so we don't lose it. Not sure whether we can or will actually do anything with this though.

Answer 6

Comment made by: alexmiller

This is related to CLJ-2080 as it's the same basic issue of what {{map-of}} and {{every-kv}} actually expect as valid inputs, which is: something that seqs to map entries. We can't really write a predicate for it without an interface "ISeqsToMapEntries" (intentionally bad name) to indicate this. java.util.Map, IPersistentMap, etc imply this, but an object can seq to map entries without meeting all the constraints of those much broader interfaces. ILookup does not and should not imply this.

Answer 7

Reference: https://clojure.atlassian.net/browse/CLJ-2041 (reported by halgari)