From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 28 Feb 2013 17:18:40 GMT
Subject: Re: [PATCH v8 2/5] blame: introduce $ as "end of file" in -L syntax
Message-ID: <7vk3psicgf.fsf@alter.siamese.dyndns.org>
In-Reply-To: <7973d90cfcd86a3c15776b8718ad6bd84ee7b4ac.1362069310.git.trast@student.ethz.ch>

Thomas Rast <trast@student.ethz.ch> writes:

> To save the user a lookup of the last line number, introduce $ as a
> shorthand for the last line.  This is mostly useful to spell "until
> the end of the file" as '-L<begin>,$'.

Doesn't "-L <begin>" or "-L <begin>," do that already?  If it were
to introduce "-L $-4," or "-L$-4,+2", I would understand why the
addition may be useful, but otherwise I do not think it adds much
value.

>
> Signed-off-by: Thomas Rast <trast@student.ethz.ch>
> ---
>  Documentation/line-range-format.txt | 6 ++++++
>  line-log.c                          | 8 ++++++++
>  2 files changed, 14 insertions(+)
>
> diff --git a/Documentation/line-range-format.txt b/Documentation/line-range-format.txt
> index 265bc23..9ce0688 100644
> --- a/Documentation/line-range-format.txt
> +++ b/Documentation/line-range-format.txt
> @@ -16,3 +16,9 @@ starting at the line given by <start>.
>  This is only valid for <end> and will specify a number
>  of lines before or after the line given by <start>.
>  +
> +
> +- `$`
> ++
> +A literal dollar sign can be used as a shorthand for the last line in
> +the file.
> ++
> diff --git a/line-log.c b/line-log.c
> index a24a86b..b167b00 100644
> --- a/line-log.c
> +++ b/line-log.c
> @@ -15,6 +15,14 @@ const char *parse_loc(const char *spec, nth_line_fn_t nth_line,
>  	regmatch_t match[1];
>  
>  	/*
> +	 * $ is a synonym for "the end of the file".
> +	 */
> +	if (spec[0] == '$') {
> +		*ret = lines;
> +		return spec + 1;
> +	}
> +
> +	/*
>  	 * Allow "-L <something>,+20" to mean starting at <something>
>  	 * for 20 lines, or "-L <something>,-5" for 5 lines ending at
>  	 * <something>.