From: Junio C Hamano <gitster@pobox.com>
Date: Mon, 16 May 2016 21:18:32 GMT
Subject: Re: [RFC PATCH 0/4] pathspec labels [WAS: submodule groups]
Message-ID: <xmqqlh391z2v.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <CAGZ79kZyPvAFG1TjSm76LuDLpch=7iuL_-8LYqysSESFQj-YjQ@mail.gmail.com>

Stefan Beller <sbeller@google.com> writes:

> This is another case for using ':' instead of '='.
> So I think ':' is better for this future enhancement.
>
> Also this future enhancement may ask for
>
>       git ls-files ":(attr:label=foo)"
>
> or
>
>       git ls-files ":(attr:-label)"
>
> so the user can circumvent the warn and ignore strategy. :(

That is exactly what we want, I would say, if we want to accept
"arbitrary set of attributes with their states".

The "warn and ignore" comes only from "with '(:label=X Y Z)', we
inspect attributes X, Y and Z and insist them to be set to true; it
is a configuration error to set the label to anything but a string",
and accepting "arbitrary set of attributes with their states" makes
it moot (as I said earlier in $gmane/294776).

So are we leaning towards ":(attr:<state>)", where <state> is one of

    var=value
    var
    -var
    !var

now?  It makes the pathspec magic parser a bit more complex (and I
am not sure if we have to worry too much about quoting "value" part
to allow arbitrary sequence of bytes), though.