JSONRPC objects in Elisp

Emacs’s preferred way of representing JSON is via Lisp lists. In Eglot, the syntax of this list is the simplest possible (the one with fewer parenthesis), a plist (see Property Lists in GNU Emacs Lisp Reference Manual).

The plist may be arbitrarily complex, and generally containing other keyword-value property sub-plists corresponding to JSON sub-objects.

For representing the JSON leaf values true, false, null and {}, you can use the Lisp values t, :json-false, nil, and eglot-{}, respectively. JSON arrays are represented as Elisp vectors surrounded by square brackets (see Vectors in GNU Emacs Lisp Reference Manual).

For example, the plist

(:pylsp (:plugins (:jedi_completion (:include_params t
                                     :fuzzy t
                                     :cache_for ["pandas" "numpy"])
                   :pylint (:enabled :json-false)))
 :gopls (:usePlaceholders t))

is serialized by Eglot to the following JSON text:

{
  "pylsp": {
    "plugins": {
      "jedi_completion": {
        "include_params": true,
        "fuzzy": true,
        "cache_for": [ "pandas", "numpy" ]
      },
      "pylint": {
        "enabled": false
      }
    }
  },
  "gopls": {
    "usePlaceholders": true
  }
}