From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 10 May 2018 06:43:30 GMT
Subject: Re: [PATCH v5 5/7] builtin/grep.c: add '--column' option to 'git-grep(1)'
Message-ID: <xmqqk1scj9il.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <4640b041-f66c-3c1f-1329-baa4580df5cc@web.de>

René Scharfe <l.s.r@web.de> writes:

> Am 10.05.2018 um 02:04 schrieb Junio C Hamano:
> ...
>>      $ git grep -v second
>>      $ git grep --not -e second
>> 
>> may hit all lines in this message (except for the obvious two
>> lines), but we cannot say which column we found a hit.  I am
>> wondering if it is too grave a sin to report "the whole line is what
>> satisfied the criteria given" and say the match lies at column #1.

And if we are planning to use this to implement '-o', then I'd
suggest that we'd say the matched part of the line is the whole
thing (i.e. so is column #1, eo is at the eol).

>> By doing so, obviously we can sidestep the whole "this mode is
>> sometimes incompatible" and "I need to compute a lot to see if the
>> given expression is compatible or not" issues.
>
> FWIW, Silver Searcher 2.1.0 does just that:
>
> 	$ echo a | ag --column -v b
> 	1:a
>
> ripgrep 0.8.1 as well:
>
> 	$ echo a | rg --column -v b
> 	1:1:a

Thanks for additional datapoints.