Case-sensitivity in regular expressions and sparse trees for tags

Case-sensitivity in regular expressions and sparse trees for tags

[Chris Randle]

Hi Gerrit

Forgive me if I've misunderstood regular expressions in Emacs or
Org-mode in some fundamental way!

I have some tags which begin "CD" followed by a number. For example

* Tagged Heading  :CD123:

When I ask for a sparse tree of all tags beginning with "CD", I do

'C-c / T'

And ask for tags of

{^CD.*}

This doesn't return any of the tagged headlines, but this does:

{^cd.*}

Is this a bug, or my misunderstanding? Obviously this is no
show-stopper, I just make sure that all my regexp searches are in lower
case, but thought I'd check.

-- 
Chris Randle
Windows XP SP3 - GNU Emacs 22.1.1 - Org-mode 6.06b

Re: Case-sensitivity in regular expressions and sparse trees for tags

[Carsten Dominik]

Hi Chris,

On Sep 17, 2008, at 9:38 PM, Chris Randle wrote:

> Hi Gerrit
>
> Forgive me if I've misunderstood regular expressions in Emacs or
> Org-mode in some fundamental way!
>
> I have some tags which begin "CD" followed by a number. For example
>
> * Tagged Heading  :CD123:
>
> When I ask for a sparse tree of all tags beginning with "CD", I do
>
> 'C-c / T'
>
> And ask for tags of
>
> {^CD.*}
>
> This doesn't return any of the tagged headlines, but this does:
>
> {^cd.*}
>
> Is this a bug, or my misunderstanding? Obviously this is no
> show-stopper, I just make sure that all my regexp searches are in  
> lower
> case, but thought I'd check.

It may be a bug, and a misunderstanding.

1. I do downcase all tage before they are tested in the matcher.
2. This seems to indicate that I do want the matching to be case- 
insensitive.
3. I do set case-fold-search to nil, which seems to contradict (2)


For now, I recommend to write all regexps with lower case letters.  I  
need to try to remember why I did not set case-fold-search.

Thanks for the report.

- Carsten


>
>
> -- 
> Chris Randle
> Windows XP SP3 - GNU Emacs 22.1.1 - Org-mode 6.06b
>
>
>
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Re: Case-sensitivity in regular expressions and sparse trees for tags

[Carsten Dominik]

On Sep 18, 2008, at 5:43 PM, Carsten Dominik wrote:

> Hi Chris,
>
> On Sep 17, 2008, at 9:38 PM, Chris Randle wrote:
>
>> Hi Gerrit
>>
>> Forgive me if I've misunderstood regular expressions in Emacs or
>> Org-mode in some fundamental way!
>>
>> I have some tags which begin "CD" followed by a number. For example
>>
>> * Tagged Heading  :CD123:
>>
>> When I ask for a sparse tree of all tags beginning with "CD", I do
>>
>> 'C-c / T'
>>
>> And ask for tags of
>>
>> {^CD.*}
>>
>> This doesn't return any of the tagged headlines, but this does:
>>
>> {^cd.*}
>>
>> Is this a bug, or my misunderstanding? Obviously this is no
>> show-stopper, I just make sure that all my regexp searches are in  
>> lower
>> case, but thought I'd check.
>
> It may be a bug, and a misunderstanding.
>
> 1. I do downcase all tage before they are tested in the matcher.
> 2. This seems to indicate that I do want the matching to be case- 
> insensitive.
> 3. I do set case-fold-search to nil, which seems to contradict (2)
>
>
> For now, I recommend to write all regexps with lower case letters.   
> I need to try to remember why I did not set case-fold-search.

I am pushing a fix today which will mkae sure that tags matching is  
truly case insensitive.  So that should make your old regexp work again.

- Carsten