convert.clj -- babashka edn/json/yaml to edn/json/yaml converter

convert.clj

#!/usr/bin/env bb
;; convert.clj -- babashka edn/json/yaml to edn/json/yaml converter
;; Author: github.com/KGOH/
;; Source: gist.github.com/KGOH/50c0f66022fea2ac173518a143238058
;; Version: 2020.3

; Usage example:
; In Emacs: i.imgur.com/TIEDmga.mp4
; $ convert.clj edn <<< '{"foo": "bar"}'
; {:foo "bar"}
; $ convert.clj yaml <<< '{:foo "bar"}'
; {foo: "bar"}

; Emacs:
; (defun try-convert (out)
;   (shell-command-on-region
;    (region-beginning) (region-end)
;    (format "convert.clj %s " out)
;    nil "REPLACE" nil t))
; (defun convert-to-edn  () (interactive) (try-convert "edn"))
; (defun convert-to-json () (interactive) (try-convert "json"))
; (defun convert-to-yaml () (interactive) (try-convert "yaml"))

; And my spacemacs keybindings:
; (spacemacs/set-leader-keys
;   "oe" 'convert-to-edn
;   "oj" 'convert-to-json
;   "oy" 'convert-to-yaml)

(ns converter
  (:require [clojure.string :as str]
            [clojure.java.io :as io]
            [clojure.pprint :as pprint]
            [clojure.edn :as edn]
            [cheshire.core :as json]
            [clojure.walk :as walk]
            [clj-yaml.core :as yaml]))

(def vectorify
  "clj-yaml.core/parse-string returns lists instead of vectors"
  (partial walk/postwalk #(cond-> % (sequential? %) vec)))

(defn try-convert [out s]
  (let [parsers [(comp vectorify yaml/parse-string) edn/read-string]
        out-convert (case out
                      :edn  #(with-out-str (pprint/pprint %))
                      :json #(json/generate-string % {:pretty true})
                      :yaml yaml/generate-string
                      (constantly nil))]
    (some->> parsers
             (keep (fn [parser] (try (parser s) (catch Exception _))))
             first
             out-convert)))

(let [[out]     *command-line-args*
      [l :as s] (->> (io/reader *in*) line-seq)
      pad       (->> l (take-while #{\space}) str/join)]
  (print (or (cond-> (some->> s (str/join \newline) (try-convert (keyword out)) str/trim)
               (< 0 (count pad))
               (->> str/split-lines (map (partial str pad)) (str/join \newline)))
             s)))