First-class map syntax (with compact-maps)

[ikitommi]

Currently, the primary syntax for defining Malli schemas is the hiccup syntax. Malli also supports map syntax and a symmetric round-trip between the two. This is ok, but the we should investigate if a more compact map presentation would make sense, as a first-class concept:

Current

(def Fruit
  [:enum {:title "fruit"
          :description "a possible fruits"
          :swagger/default "apple"}
   "pear" "lemon"])

(m/form Fruit)
;[:enum {:title "fruit"
;        :description "a possible fruits"
;        :swagger/default "apple"}
; "pear" "lemon"]

(mu/to-map-syntax Fruit)
;{:type :enum,
; :properties {:title "fruit"
;              :description "a possible fruits"
;              :swagger/default "apple"},
; :children ["pear" "lemon"]}

(-> Fruit mu/to-map-syntax mu/from-map-syntax m/form (= Fruit))
; => true

Idea

(m/form Fruit {:syntax :hiccup})
;[:enum {:title "fruit"
;        :description "a possible fruits"
;        :swagger/default "apple"}
; "pear" "lemon"]

(m/form Fruit {:syntax :map})
;{:type :enum,
; :properties {:title "fruit"
;              :description "a possible fruits"
;              :swagger/default "apple"},
; :children ["pear" "lemon"]}

(m/form Fruit {:syntax :map-compact})
;{:malli/type :enum
; :title "fruit"
; :description "a possible fruits"
; :swagger/default "apple"
; :malli/children ["pear" "lemon"]}

Parsed childs

the last one would be great for cases where the children have a special meaning (like :=>), could be derived from m/parse results.

so, instead of:

(m/form [:=> {:doc "fn"} :cat :nil] {:syntax :map})
; {:type :=>
;  :properties {:doc "fn"}
;  :children [{:type :cat}
;             {:type :nil}]}

it would be:

(m/form [:=> {:doc "fn"} :cat :nil] {:syntax :map-compact})
;{:malli/type :=>
; :doc "fn"
; :malli/input {:malli/type :cat}
; :malli/output {:malli/type :nil}}

like clj-fx.

[ikitommi]

.. eventually, we should only support one map-syntax. With that, m/schema could support both, e.g. the following would mean the same:

(m/schema
  {:malli/type :=>
   :doc "fn"
   :malli/input {:malli/type :cat}
   :malli/output {:malli/type :nil}})

(m/schema [:=> {:doc "fn"} :cat :nil])