to-pull-expression

pull_util.clj

(ns pull-util)

(defn to-pull-expression
  "Naively build pull expression from given tree. Doesn't work with refs
   that are represented by idents (keywords), e.g. enums, at the moment."
  [tree]
  (letfn [(card-many-ref? [v]
            (and (sequential? v)
                 (every? map? v)))
          (branch? [v]
            (or (map? v) (card-many-ref? v)))]
    (let [{branch-kvps true
           leaf-kvps false} (group-by (fn [[_ v]] (branch? v)) tree)
          map-spec (into {} (map (fn [[k v]]
                                   (let [sub-exp (if (sequential? v)
                                                   (vec (mapcat to-pull-expression v))
                                                   (to-pull-expression v))]
                                     [k sub-exp])))
                         branch-kvps)
          leaves (into [] (map first) leaf-kvps)]
      (if (seq map-spec)
        (conj leaves map-spec)
        leaves))))