[PATCH 2 of 2] templatekw: add a {negrev} keyword

[Jordi Gutiérrez Hermoso]

On Thu, 2018-01-18 at 21:05 +0900, Yuya Nishihara wrote:
> On Wed, 17 Jan 2018 22:14:30 -0500, Jordi Gutiérrez Hermoso wrote:
> > # HG changeset patch
> > # User Jordi Gutiérrez Hermoso <jordigh at octave.org>
> > # Date 1516243120 18000
> > #      Wed Jan 17 21:38:40 2018 -0500
> > # Node ID cbf1d676a938e78d40cd3504dd916f787bcb47ee
> > # Parent  701f8a9defdc09bb63f2596e2fc426f2e78da313
> > templatekw: add a {negrev} keyword
> > 
> > Revision numbers are getting much maligned for two reasons: they
> > are
> > too long in large repos and users get confused by their local-only
> > nature. It just occurred to me that negative revision numbers avoid
> > both of those problems. Since negative revision numbers change
> > whenever the repo changes, it's much more obvious that they are a
> > local-only convenience. Additionally, for the recent commits that
> > we
> > usually care about the most, negative revision numbers are always
> > near
> > zero.
> > 
> > This commit adds a negrev templatekw to more easily expose negative
> > revision numbers. It's not easy to reliably produce this output
> > with
> > existing keywords due to hidden commits or without a significant
> > slowdown due to computing a complicated template expression.
> 
> Isn't it "{rev - revset("tip")|stringify - 1}" ? Well, the stringify
> looks strange, but not terrible.

That's incorrect if tip is hidden. And much noticeably slower.