;; -*- lexical-binding: t; -*-

(require 'cl-lib)
(require 'mal/types)
(require 'mal/reader)
(require 'mal/printer)


(defun READ (input)
  (read-str input))

(defun EVAL (input)
  input)

(defun PRINT (input)
  (pr-str input t))

(defun rep (input)
  (PRINT (EVAL (READ input))))

(defun readln (prompt)
  ;; C-d throws an error
  (ignore-errors (read-from-minibuffer prompt)))

(defun println (format-string &rest args)
  (princ (if args
             (apply 'format format-string args)
           format-string))
  (terpri))

(defmacro with-error-handling (&rest body)
  `(condition-case err
       (progn ,@body)
     (end-of-token-stream
      ;; empty input, carry on
      )
     (unterminated-sequence
      (princ (format "Expected '%c', got EOF\n"
                     (cl-case (cadr err)
                       (string ?\")
                       (list   ?\))
                       (vector ?\])
                       (map    ?})))))
     (error ; catch-all
      (println (error-message-string err)))))

(defun main ()
  (let (input)
    (while (setq input (readln "user> "))
      (with-error-handling
       (println (rep input))))
    ;; print final newline
    (terpri)))

(main)