bug#37538: [PATCH] Add docstring for `tags-complete-tags-table-file'.

[Hong Xu <hong@topbug.net>]

On 9/28/19 1:11 AM, Eli Zaretskii wrote:
>> From: Hong Xu <hong@topbug.net>
>> Date: Sat, 28 Sep 2019 00:59:21 -0700
>>
>> * lisp/progmodes/etags.el (tags-complete-tags-table-file): Add docstring.
> 
> Thanks.  A comment below.
> 
>> -(defun tags-complete-tags-table-file (string predicate what) ; Doc string?
>> +(defun tags-complete-tags-table-file (string predicate what)
>> +  "Complete file names in the current tags table.
>> +The meaning of the arguments are the same as the function form of
>> +COLLECTION as explained in Info node `(elisp) Programmed
>> +Completion'."
> 
> The first line of the doc string should mention the arguments.  And we
> should explain STRING and WHAT there, because those aren't passed to
> all-completions and try-completion.
> 

Please see my update below. I'm writing in this concise form because `(elisp) Programmed Completion' has a lot of explanation and I don't think we should repeat them here.

diff --git a/lisp/progmodes/etags.el b/lisp/progmodes/etags.el
index a03516100087..2770baa7067c 100644
--- a/lisp/progmodes/etags.el
+++ b/lisp/progmodes/etags.el
@@ -1843,13 +1843,18 @@ tags-query-replace
     delimited)
    (fileloop-continue))
  
-(defun tags-complete-tags-table-file (string predicate what) ; Doc string?
+(defun tags-complete-tags-table-file (string predicate what)
+  "Complete STRING from file names in the current tags table.
+The meaning of the arguments are the same as the function form of
+COLLECTION as explained in Info node `(elisp) Programmed
+Completion', except that if WHAT does not equal t, it is treated
+as if it were nil."
    (save-excursion
      ;; If we need to ask for the tag table, allow that.
      (let ((enable-recursive-minibuffers t))
        (visit-tags-table-buffer))
      (if (eq what t)
-       (all-completions string (tags-table-files) predicate)
+        (all-completions string (tags-table-files) predicate)
        (try-completion string (tags-table-files) predicate))))
  
  ;;;###autoload
-- 
2.20.1