datomic-pullups

Merge Datomic Pull syntax via union and intersection.

Usage

(require '[lab79.datomic-pullups :as dp])

Given two pull patterns, e.g.:

(def pull1 [:foo :bar])
(def pull2 [:foo :qux :cow])

We can get the union of them:

(dp/compose-pull-patterns [pull1 pull2])
;;=>
(:foo :bar :qux :cow)

We can also get the intersection:

(dp/intersect-pull-patterns pull1 pull2)
;;=>
[:foo]

It works on deeply nested patterns too:

;; union
(dp/compose-pull-patterns
  [[{:user/access-groups
     [{:access-group/members
       [:person.id/ssn
        {:person/name [:person.name/family]}]}]}]
   [{:user/access-groups
     [{:access-group/members
       [{:person/name [:person.name/given]}]}]}]])
;; =>
(#:user{:access-groups
  (#:access-group{:members
    (:person.id/ssn #:person{:name (:person.name/family :person.name/given)})})})
;; intersection
(dp/intersect-pull-patterns
  [{:user/access-groups
     [{:access-group/members
       [:person.id/ssn
        {:person/name [:person.name/given :person.name/family]}]}]}]
   [{:user/access-groups
     [{:access-group/members
       [{:person/name [:person.name/given]}]}]}])
;; =>
[#:user{:access-groups
  [#:access-group{:members
    [#:person{:name [:person.name/given]}]}]}]

See the tests for more examples.

Limitations

It does not currently support the full range of Datomic syntax:

• does not explicitly support *

Limitations are captured in commented-out tests.

License

Copyright © 2017 Lab79, Inc.

Distributed under the MIT License.