Re: [PATCH/RFC] blame: accept multiple -L ranges

[Michael Haggerty <mhagger@alum.mit.edu>]

On 07/09/2013 09:31 PM, Junio C Hamano wrote:
> Thomas Rast <trast@inf.ethz.ch> writes:
> 
>> If you define it that way, the output of
>>
>>   git blame -L 4,6; git blame -L /A/,+20
>>
>> is significantly different from
>>
>>   git blame -L 4,6 -L /A/,+20
>>
>> Not just in the presentation or any possible coalescing, but in the
>> meaning of the ranges.
>>
>> Do you really want to make it that way?
> 
> Absolutely.  The primary reason I want to be able to specify two
> ranges at the same time is to follow two functions in a file that
> appear in separate places, and /A/ might not be unique.  When I want
> to say "I want to see from here to there, and then from here to
> there, and then from here to there", it would be very frustrating if
> "and then" resets what I mean by "here" every time and make these
> three evaluated independently.

It would be more general to support "follow the second match to /A/"
*independent* of whether the first match is also followed.  I think your
proposal only allows the second to be followed if the first is also
followed.  Therefore it seems to me that your wish is to add a
side-effect to one feature so that you can use it to obtain a simulacrum
of a second feature, instead of building the second feature directly.

Perhaps allow <start> and <end> to be a sequence of forms like

/A//A/,+20

    Start at the second occurrence of /A/ an continue for 20 lines

/A/+20,/B/

    Start 20 lines after the first match of /A/ until the subsequent
match of /B/

E.g., the body of function "foo" would be '/^int foo//^{/+1,/^}/-1'.
That should provide hours of amusement to baffled users ;-)

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu
http://softwareswirl.blogspot.com/