Re: [PATCH 2/5] Immediately return if scope is region but no region is active

[Carsten Dominik <carsten.dominik@gmail.com>]

On Aug 28, 2011, at 4:00 PM, David Maus wrote:

> Hi Carsten,
> 
> At Thu, 25 Aug 2011 07:43:48 +0200,
> Carsten Dominik wrote:
>> 
>> 
>> On 25.8.2011, at 06:25, David Maus wrote:
>> 
>>> * org.el (org-map-entries): Immediately return if scope is region but
>>> no region is active.
>>> ---
>>> lisp/org.el |  116 ++++++++++++++++++++++++++++++-----------------------------
>>> 1 files changed, 59 insertions(+), 57 deletions(-)
>>> 
>>> diff --git a/lisp/org.el b/lisp/org.el
>>> index b69b77c..27bad52 100644
>>> --- a/lisp/org.el
>>> +++ b/lisp/org.el
>>> @@ -13608,65 +13608,67 @@ with `org-get-tags-at'.  If your function gets properties with
>>> to t around the call to `org-entry-properties' to get the same speedup.
>>> Note that if your function moves around to retrieve tags and properties at
>>> a *different* entry, you cannot use these techniques."
>>> -  (let* ((org-agenda-archives-mode nil) ; just to make sure
>>> -	 (org-agenda-skip-archived-trees (memq 'archive skip))
>>> -	 (org-agenda-skip-comment-trees (memq 'comment skip))
>>> -	 (org-agenda-skip-function
>>> -	  (car (org-delete-all '(comment archive) skip)))
>>> -	 (org-tags-match-list-sublevels t)
>>> -	 matcher file res
>>> -	 org-todo-keywords-for-agenda
>>> -	 org-done-keywords-for-agenda
>>> -	 org-todo-keyword-alist-for-agenda
>>> -	 org-drawers-for-agenda
>>> -	 org-tag-alist-for-agenda)
>>> +  (unless (and (eq scope 'region)
>>> +	       (not (org-region-active-p)))
>> 
>> Would it be good to throw an error here?
>> 
>> (if (and (eq scope 'region) (not (org-region-active-p)))
>>    (error "No active region")
> 
> Not necessarily. I look at map-entries as a function that applies FUNC
> to a subset of all headlines. SCOPE, MATCH, and SKIP are selectors
> that narrow down the set of headlines.  First SCOPE is applied to the
> set containing all headlines, than MATCH is applied to the set of
> headlines selected by SCOPE, finally FUNC is applied to all headlines
> in the final subset if not SKIP.
> 
> If you look at `org-map-entries' this way then calling it with SCOPE
> 'region but no active region is not an error. How many headlines are
> in the active region if there is no active region? Exactly zero. Its
> the same with a SCOPE 'file but no headline in current file.
> 
> Applying SCOPE to the set of all headings produces the empty set
> and `org-map-entries' can simply leave because MATCH and SKIP wouldn't
> match anything.

Yes, I agree, I think you are right.  Thanks!

- Carsten