`lasagna-pull` cannot pull all map keys or values

[flybot-nam-nguyenhoai]

Problem

When pulling data from a map, lasagna-pull requires all map keys to be provided up front. There is no way to discover all map keys or all map values. For example:

(def entity-map
  {#uuid "123456" {:attr1 :v1 :attr2 :v2}
   #uuid "234567" {:attr1 :v3 :attr2 :v4}})

;; There is no way to pull [#uuid "123456", #uuid "234567"] or [{:attr1 :v1}, {:attr1 :v3}].

Impact

It is difficult to work with index–entity maps in which indexes (keys) are generated dynamically, like entity-map above.

These maps are common when working with UI entities in re-frame.

Suggestion

• Implement patterns for pulling all map keys or values, similar to Specter’s MAP-KEYS and MAP-VALS, respectively.