Re: [PATCH] pretty: Add %(trailer:X) to display single trailer

From: Jeff King <peff@peff.net>
To: Anders Waldenborg <anders@0x63.nu>
Cc: Olga Telezhnaya <olyatelezhnaya@gmail.com>,
	git@vger.kernel.org, gitster@pobox.com
Subject: Re: [PATCH] pretty: Add %(trailer:X) to display single trailer
Date: Thu, 1 Nov 2018 14:42:19 -0400	[thread overview]
Message-ID: <20181101184219.GA2918@sigill.intra.peff.net> (raw)
In-Reply-To: <87a7mtlnzr.fsf@0x63.nu>

On Thu, Nov 01, 2018 at 12:01:28AM +0100, Anders Waldenborg wrote:

> Jeff King writes:
> 
> > On the other hand, if the rule were not "this affects the next
> > placeholder" but had a true ending mark, then we could make a real
> > parse-tree out of it, and format chunks of placeholders. E.g.:
> >
> >   %(format:lpad=30,filename)%(subject) %(authordate)%(end)
> >
> > would pad and format the whole string with two placeholders. I know that
> > going down this road eventually involves reinventing XML, but I think
> > having an actual tree structure may not be an unreasonable thing to
> > shoot for.
> 
> Yes. I'm thinking that with [] for formatting specifiers and () for
> placeholders, {} would be available for nesting. E.g:
> 
>    %[lpad=30,mangle]{%(subject) %ad%}

Hmm. That's kind of ugly, but probably not really any uglier than any of
the things I showed. And it has the advantage that we could implement
%[] now, and later extend it (well, I guess we'd want to make sure that
"%[lpad=30]{foo}" does not treat the curly braces literally, since we'd
eventually make them syntactically significant).

> I'm planning to work on the initial "trailer:key=" part later this
> week. Maybe I can play around with different formatting options and see
> how it affects the parser.

Great! Thanks for working on this.

-Peff