elisp/env.el

   1 (defun mal-env (&optional outer binds exprs)
   2   (let ((env (vector 'env (vector (make-hash-table :test 'eq) outer))))
   3     (while binds
   4       (let ((key (pop binds)))
   5         (if (eq key '&)
   6             (let ((key (pop binds))
   7                   (value (mal-list exprs)))
   8               (mal-env-set env key value)
   9               (setq binds nil
  10                     exprs nil))
  11           (let ((value (pop exprs)))
  12             (mal-env-set env key value)))))
  13     env))
  14
  15 (defun mal-env-set (env key value)
  16   (let ((data (aref (aref env 1) 0)))
  17     (puthash key value data)))
  18
  19 (defun mal-env-find (env key)
  20   (let* ((data (aref (aref env 1) 0))
  21          (value (gethash key data)))
  22     (if (not value)
  23         (let ((outer (aref (aref env 1) 1)))
  24           (when outer
  25             (mal-env-find outer key)))
  26       value)))
  27
  28 (defun mal-env-get (env key)
  29   (let ((value (mal-env-find env key)))
  30     (if (not value)
  31         (error "'%s' not found" key)
  32       value)))