bug#18202: 24.4.50; doc string of `next-error-buffer-p'

bug#18202: 24.4.50; doc string of `next-error-buffer-p'

[Drew Adams]

The doc string:

 Test if BUFFER is a `next-error' capable buffer.

 If AVOID-CURRENT is non-nil, treat the current buffer
 as an absolute last resort only.

 The function EXTRA-TEST-INCLUSIVE, if non-nil, is called in each buffer
 that normally would not qualify.  If it returns t, the buffer
 in question is treated as usable.

 The function EXTRA-TEST-EXCLUSIVE, if non-nil, is called in each buffer
 that would normally be considered usable.  If it returns nil,
 that buffer is rejected.

The doc string is very poor.

1. The first line should say that the predicate returns non-nil if
   BUFFER is a `next-error'-capable buffer.

2. The doc string should then give some indication of what that means
   (what it means for a buffer to be `next-error'-capable).

3. The description of AVOID-CURRENT says nothing.  It needs to say what
   the behavior is and how it affects the return value (if it does).
   "Treat the buffer" means nothing here, as does "as a last resort."

4. The other two paragraphs: What does it mean (a) for a buffer to
   "qualify" or "normally be considered usable" ("normally"?  What does
   that mean here?), and (b) for a buffer to be "usable" or "rejected"?
   Again, this text says nothing helpful.  It should say what the
   behavior is.

   Presumably, the last sentence in each of these paragraphs should say
   "If it returns [t|nil] then so does `next-error-buffer-p'."

There really is nothing good about this doc string.  

In GNU Emacs 24.4.50.1 (i686-pc-mingw32)
 of 2014-06-28 on ODIEONE
Bzr revision: 117431 rgm@gnu.org-20140628015517-eku6hj8mpgcvfnso
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --prefix=/c/Devel/emacs/snapshot/trunk
 --enable-checking=yes,glyphs 'CFLAGS=-O0 -g3'
 LDFLAGS=-Lc:/Devel/emacs/lib 'CPPFLAGS=-DGC_MCHECK=1
 -Ic:/Devel/emacs/include''

bug#18202: 24.4.50; doc string of `next-error-buffer-p'

[Lars Ingebrigtsen]

Drew Adams <drew.adams@oracle.com> writes:

> The doc string:
>
>  Test if BUFFER is a `next-error' capable buffer.
>
>  If AVOID-CURRENT is non-nil, treat the current buffer
>  as an absolute last resort only.
>
>  The function EXTRA-TEST-INCLUSIVE, if non-nil, is called in each buffer
>  that normally would not qualify.  If it returns t, the buffer
>  in question is treated as usable.
>
>  The function EXTRA-TEST-EXCLUSIVE, if non-nil, is called in each buffer
>  that would normally be considered usable.  If it returns nil,
>  that buffer is rejected.
>
> The doc string is very poor.
>
> 1. The first line should say that the predicate returns non-nil if
>    BUFFER is a `next-error'-capable buffer.

Fixed.

> 2. The doc string should then give some indication of what that means
>    (what it means for a buffer to be `next-error'-capable).

Hm...  No I think that's pretty evident.  It's a buffer in which the
command `next-error' makes sense.

> 3. The description of AVOID-CURRENT says nothing.  It needs to say what
>    the behavior is and how it affects the return value (if it does).
>    "Treat the buffer" means nothing here, as does "as a last resort."

Yes, that's odd.  Looking at the code, it just means that it returns nil
if given and BUFFER is the current buffer.  Fixed.

> 4. The other two paragraphs: What does it mean (a) for a buffer to
>    "qualify" or "normally be considered usable" ("normally"?  What does
>    that mean here?), and (b) for a buffer to be "usable" or "rejected"?
>    Again, this text says nothing helpful.  It should say what the
>    behavior is.
>
>    Presumably, the last sentence in each of these paragraphs should say
>    "If it returns [t|nil] then so does `next-error-buffer-p'."

Fixed.

> There really is nothing good about this doc string.  

It's an almost verbatim copy of the doc string from
`next-error-find-buffer', which explains why it's so odd.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no