[PATCH 3 of 8] match: add the abs() method

[Matt Mackall]

On Tue, 2014-12-23 at 19:55 -0500, Matt Harbison wrote:
> On Tue, 23 Dec 2014 17:01:25 -0500, Matt Mackall <mpm at selenic.com> wrote:
> 
> > On Tue, 2014-12-23 at 15:56 -0500, Matt Harbison wrote:
> >> # HG changeset patch
> >> # User Matt Harbison <matt_harbison at yahoo.com>
> >> # Date 1417223746 18000
> >> #      Fri Nov 28 20:15:46 2014 -0500
> >> # Node ID aa5998c14c5c8407869cc728e41940130e390ba3
> >> # Parent  04de3b9ae56e98740c83ee342b68d735b7e9ec73
> >> match: add the abs() method
> >>
> >> This is a utility to make it easier for subrepos to convert a file name  
> >> to the
> >> full path rooted at the top repository.  It can replace the various  
> >> path joining
> >> lambdas, and doesn't require the prefix to be passed into the method  
> >> that wishes
> >> to build such a path.  It will also allow making the manner in which  
> >> absolute
> >> subrepo paths are displayed on Windows consistent with the way absolute  
> >> repo
> >> paths are- i.e. with '/' as the separator, instead of the current mix  
> >> of '\'
> >> and '/'.
> >
> > This is not ideal. First, we _really_ need to stop using os methods in
> > core code, especially in furtherance of anything related to Windows:
> >
> > http://mercurial.selenic.com/wiki/WindowsUTF8Plan
> >
> > Second, the matcher currently doesn't use os at all, which should be an
> > alarm bell: it's intentionally completely OS-agnostic at present. This
> > is important because it's used against both working copy and in-history
> > paths.
> >
> > I like the idea of this abs() method, but trying to solve cross-OS slash
> > issues at the same time as you introduce it is tying a very heavy boat
> > anchor to it.
> >
> > Also, queuebot sends its regards.
> >
> 
> I cooked up something that uses vfs, but there is a new import cycle with  
> match -> scmutil -> match.  Obviously it isn't desirable, but I don't know  
> if it is acceptable.  We can probably move most of the match wrapper  
> methods to the match module (e.g. matchandpats(), etc).  But  
> scmutil.expandpats() also uses a match module method, and I'm not sure it  
> fits in the match module.
> 
> Thoughts?

I think you should just use naive prefix + "/" + path internal to match
and use util.localpath for display purposes.

-- 
Mathematics is the supreme nostalgia of our time.