Re: Find tags with dot character

[Pascal Quesseveur]

>"SM" == Stefan Monnier <monnier@iro.umontreal.ca> writes:

  SM> In case of an error (or a C-g) during the execution of find-tag-default,
  SM> this will fail to restore the syntax-table to its original state, so
  SM> I recommend:

  SM>     (defun my-find-tag-default-opascal ()
  SM>       (unwind-protect
  SM>           (progn (modify-syntax-entry ?. "w")
  SM>                  (find-tag-default))
  SM>         (modify-syntax-entry ?. ".")))

OK.

> And in Delphi mode hook, I added:
>
> (setq find-tag-default-function 'my-find-tag-default-opascal)

  SM> This likely affects the variable globally, so maybe you'd want
  SM> to use `setq-local` instead.

Yes, thank you.

  SM> Your approach above will make thing worse in several important
  SM> use cases (e.g. when point is on "<var>.<method>" where we won't
  SM> find that tag anywhere (we'd have to lookup something like
  SM> "<class>.<method>" instead))

Yes, we need both.

  SM> is by default, but I think we'd welcome patches which try to
  SM> improve on this (e.g. by first trying with the dots and if that
  SM> fails try again without them).

I'm afraid I'm not expert enough to propose a modification of etags,
either etags the program or the etags handling in emacs. In addition i
use an old version of emacs (24.3) for delphi devlopment, where I
don't have the new opascal mode, only delphi-mode. I still tried and
produced those functions:

(defun my-find-tag-opascal-helper (prompt)
  "Helper to call find-tag and catch errors. I was unable to call
find-tag-interactive, so I used find-tag-tag without any
options."
  (condition-case err
      (let ((tagname (find-tag-tag prompt)))
        (find-tag tagname)
        t)
    (error (message "%s" (error-message-string err))
           nil)))

(defun my-find-tag-opascal()
  "First call find-tag using current find-tag-default-function,
and when no tags are found call find-tag again with
find-tag-default-function set to nil."
  (interactive)
  (let ((xp (point))
        (xb (current-buffer))
        tfunc)
    (unless (my-find-tag-opascal-helper "Find tag: ")
      (set-buffer xb)
      (goto-char xp)
      (setq tfunc find-tag-default-function)
      (setq-local find-tag-default-function nil)
      (unwind-protect
          (my-find-tag-opascal-helper "Tag not found. Retry with: ")
        (set-buffer xb)
        (setq-local find-tag-default-function tfunc)))))


-- 
Pascal Quesseveur
pquessev@gmail.com