Errors as data compose, error messages not so much

errors_as_data.clj

;; spec errors are data, and as such are composable with all the rest
;; of Clojure. The forms below show getting to an interesting part
;; of an error in a larger data structure, taking advantage of
;; edn-reading, pretty-printing, *print-length* and threading macro.

;; It is difficult to maintain the compositionality shown here
;; once you convert error data into e.g. ASCII art.

(require
 '[clojure.edn :as edn]
 '[clojure.pprint :as pp])
(set! *print-length* 5)
(def error
  (edn/read-string
   {:readers {'error identity}}
   (slurp "https://gist.githubusercontent.com/jjl/d44c38984dce72c9d083975f7b475e5a/raw/38dd260fff8c6001ecceb978a351179e3c2d1ba5/gistfile1.txt")))
(-> error :data :explain :cljs.spec/problems first pp/pprint)

{:path [:paths],
 :pred string?,
 :val
 [[0 -10 -3.3333333333333335]
  [0 -9 -3]
  [0 -8 -2.6666666666666665]
  [0 -7 -2.3333333333333335]
  [0 -6 -2]
  ...],
 :via
 [:irresponsible.babylonians/ribbon-opts
  :irresponsible.babylonians/paths
  :irresponsible.babylonians/path],
 :in [:paths 0]}