Hi all, When I wrote my simple extension, pure elisp code is ok. But I found it is hard to write complex elisp extension. Because when elisp predication failed (for example stringp) it hard to find out the failed predication place. (no file:function:line_number or backtrace) So my complex extension is elisp + c++ code and I make elisp as simple as possible. We can link c code to emacs binary, but I don't think it's a good solution. In xemacs, we can extend elisp by writing c/c++ shared library and load it dynamicly. If emacs has this feature, my complex emacs extension can be much simpler. Does there any other good way to extend emacs? How about other emacs-alike editor like Hemlock written in common lisp which can use many mature and complex common lisp library? Does anybody use it? I think xemacs's c/c++ shared library is more suitable. But it seems that xemacs had stop its development. following link is a simple extension of mine http://www.emacswiki.org/emacs/dir-list