Emacs, namespaces and defuns

The only thing I don't like about Emacs is the lack of namespaces, so I'm wondering if I can implement them on my own.

This is my first attempt, and it's obvious that I can't just replace every match of a name with its prefixed version, but what should I check? I can check for bindings with (let) then mark the entire subtree, but what if somebody creates a (my-let) function that uses let? Is my effort destined to fail? :(

Also, why are my defuns failing to define the f开发者_高级运维unction? Do I have to run something similar to intern-symbol on every new token?

Thanks!

Since this is the first google result for elisp namespaces...

There's a minimalist implementation of namespaces called fakespace which you can get on elpa, which does basic encapsulation. I'm working on something ambitious myself, which you can check out here.

To handle things like my-let or my-defun, you need to macroexpand those definitions, e.g. with macroexpand-all.

For the failure to define the functions, you need to use intern instead of make-symbol (because make-symbol always creates a new distinct fresh uninterned symbol).

Adding namespaces will take more than prefixing the identifiers with the namespace names. The interpreter has to be able to tell the namespaces. Some tinkering must go into the interpreter as well. That might need to go through a thorough discussion at gnu.emacs.sources and/or #emacs at irc.freenode.org.

This is a fixed version of the code from @vpit3833 to provide namespace support (using the hint from @Stefan). It’s too good to leave around half-fixed :)

;; Simple namespace definitions for easier elisp writing and clean
;; access from outside. Pythonesque elisp :)
;; 
;; thanks to vpit3833 → http://6e5e5ae9206fa093.paste.se/

(defmacro namespace (prefix &rest sexps)
  (let* ((naive-dfs-map
          (lambda (fun tree)
            (mapcar (lambda (n) (if (listp n) (funcall naive-dfs-map fun n)
                                  (funcall fun n))) tree)))
         (to-rewrite (loop for sexp in sexps
                           when (member (car sexp)
                                        '(defvar defmacro defun))
                           collect (cadr sexp)))
         (fixed-sexps (funcall naive-dfs-map
                               (lambda (n) (if (member n to-rewrite)
                                               (intern
                                                (format "%s-%s" prefix n)) n))
                               sexps)))
    `(progn ,@fixed-sexps)))

;; (namespace test
;;            (defun three () 3)
;;            (defun four () (let ((three 4)) three))
;;            (defun + (&rest args) (apply #'- args)))

;; (test-+ 1 2 3)

(provide 'namespace)