Re: address@hidden: EVAL and mouse selection in *Completions*]

[martin rudalics]

> I thought your try-completion-old was a better, more comprehensive
> solution than mine. But I agree the name is poor. Why not call it
> PC-try-completion?

OK

> Also, shouldn't it return STRING, rather than "",
> for an exact match?

It should, indeed, thanks.  Please look at the attached patch.  Johan,
please have another look at this too.

> With regards to the partial completion erasing buffer thing, I don't
> know if we need to tweak completion-base-size, apply the complex fix,
> or both.

I removed this part from my patch.  Could people please try whether
Chong's `completion-base-size' fix solves this part of the symbol
completion problem.

*** complete.el Tue Jan 23 07:40:00 2007
--- complete.el Wed Mar  7 11:21:16 2007
***************
*** 383,388 ****
--- 383,411 ----
      (let ((completion-ignore-case nil))
        (test-completion str table pred))))

+ ;; The following function is an attempt to work around two problems:
+ 
+ ;; (1) When complete.el was written, (try-completion "" '(("") (""))) used to
+ ;; return the value "".  With a change from 2002-07-07 it returns t which 
caused
+ ;; `PC-lisp-complete-symbol' to fail with a "Wrong type argument: sequencep, 
t"
+ ;; error.  `PC-try-completion' returns STRING in this case.
+ 
+ ;; (2) (try-completion "" '((""))) returned t before the above-mentioned 
change.
+ ;; Since `PC-chop-word' operates on the return value of `try-completion' this
+ ;; case might have provoked a similar error as in (1).  `PC-try-completion'
+ ;; returns "" instead.  I don't know whether this is a real problem though.
+ 
+ ;; Since `PC-try-completion' is not a guaranteed to fix these bugs reliably, 
you
+ ;; should try to look at the following discussions when you encounter 
problems:
+ ;; - emacs-pretest-bug ("Partial Completion" starting 2007-02-23),
+ ;; - emacs-devel ("[address-of-OP: Partial completion]" starting 2007-02-24),
+ ;; - emacs-devel ("[address-of-OP: EVAL and mouse selection in *Completions*]"
+ ;;   starting 2007-03-05).
+ (defun PC-try-completion (string alist &optional predicate)
+   "Like `try-completion' but return STRING instead of t."
+   (let ((result (try-completion string alist predicate)))
+     (if (eq result t) string result)))
+ 
  (defun PC-do-completion (&optional mode beg end)
    (or beg (setq beg (minibuffer-prompt-end)))
    (or end (setq end (point-max)))
***************
*** 623,630 ****

            ;; Check if next few letters are the same in all cases
            (if (and (not (eq mode 'help))
!                    (setq prefix (try-completion (PC-chunk-after basestr skip)
!                                                   poss)))
                (let ((first t) i)
                  ;; Retain capitalization of user input even if
                  ;; completion-ignore-case is set.
--- 646,653 ----

            ;; Check if next few letters are the same in all cases
            (if (and (not (eq mode 'help))
!                    (setq prefix (PC-try-completion
!                                  (PC-chunk-after basestr skip) poss)))
                (let ((first t) i)
                  ;; Retain capitalization of user input even if
                  ;; completion-ignore-case is set.
***************
*** 662,668 ****
                              (setq skip (concat skip
                                                 (regexp-quote prefix)
                                                 PC-ndelims-regex)
!                                   prefix (try-completion
                                            (PC-chunk-after
                                             ;; not basestr, because that does
                                             ;; not reflect insertions
--- 685,691 ----
                              (setq skip (concat skip
                                                 (regexp-quote prefix)
                                                 PC-ndelims-regex)
!                                   prefix (PC-try-completion
                                            (PC-chunk-after
                                             ;; not basestr, because that does
                                             ;; not reflect insertions
***************
*** 996,1002 ****
                (cond
                 ((not completion-table) nil)
                 ((eq action 'lambda) (test-completion str2 completion-table 
nil))
!                ((eq action nil) (try-completion str2 completion-table nil))
                 ((eq action t) (all-completions str2 completion-table nil)))))
      ad-do-it))
  
--- 1019,1025 ----
                (cond
                 ((not completion-table) nil)
                 ((eq action 'lambda) (test-completion str2 completion-table 
nil))
!                ((eq action nil) (PC-try-completion str2 completion-table nil))
                 ((eq action t) (all-completions str2 completion-table nil)))))
      ad-do-it))