Re: Opening and Closing a buffer in elisp, and elisp regexp

[Anselm Helbig]

hi brett, 

> [writing some elisp to extract urls from an erc buffer and select
>  them for opening in another buffer]

just some short comments on your code.

> (defun get-last-urls (count)
>   "Build a list of the <count> most recent urls in the buffer"
>   (let ((urls '()))
>     (save-excursion
>       (while (or (< (length urls) count) (< (point) 0))
                                           ^^^^^^^^^^^^^
                                           point can never be smaller than 1!

you should include the search in your while condition like this

        (while (and (< (length urls) count)          
                    (search-backward-regexp "<\\(http://.*\\)\\>" nil t))
                                                                      ^- ignore 
errors!

>         (search-backward-regexp "<\\(http://.*\\)\\>")
>         (add-to-list 'urls (match-string 0))))
                                           ^- this should be 1, 0
                                              means the entire match,
                                              not the parenthesized expression
>     urls))
> 
> (defun handle-url-select ()
>   "Open the URL, close buffer - this doesn't completely work yet"
>   (progn
>     (browse-url (thing-at-point 'url))
>     (with-current-buffer buf (kill-buffer buf))))
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      this wont work. this code tries to make the buffer designated by
      `buf' current, if `buf' is unbound this will throw an error.
      use (kill-buffer (current-buffer)) instead. OTOH, (bury-buffer)
      might serve you just as well. 
 
use M-x re-builder. use M-x ielm. use the online documentation (C-h f,
C-h v, C-h i, ...). use eldoc-mode. if all else fails, have a look at
edebug. 

there may be better java-ides out there, but there's no better IDE for
elisp than emacs. 8-)

happy hacking!

anselm