Re: binary pkg "variants" ? [was: Re: Package split or package options?]

[Alistair Crooks <agc%pkgsrc.org@localhost>]

On Sat, Mar 29, 2014 at 11:21:04AM +0100, Thomas Klausner wrote:
> On Sat, Jan 18, 2014 at 03:28:52PM +0100, Anthony Mallet wrote:
> > Here are the 3 patches for pkgtools/pkg_install implementing the 
> > aforementioned
> > naming scheme in robotpkg. As such, the patches are supposed to be harmless,
> > i.e. pkgsrc/pkg_install will work exactly as before (but of course implement
> > the necessary bits for the new naming scheme, mostly affecting pkg_admin 
> > pmatch).
> > 
> > Patches 1 & 2 are just code refactoring, patch 3 implements the real stuff.
> > There is my git commit message in the patch, hopefully explaining what is
> > implemented.
> > 
> > http://www.netbsd.org/~tho/0001-pkgtools-pkg_install-Factorize-code-adding-a-version.patch
> 
> Ok, commit this after the branch.
> 
> > http://www.netbsd.org/~tho/0002-pkgtools-pkg_install-Do-not-reinvent-pkg_match-for-m.patch
> 
> Good too.
> 
> > http://www.netbsd.org/~tho/0003-pkgtools-pkg_install-Introduce-the-tags-package-suff.patch
> 
> >From the patch age I assume you've been running this for years, so commit 
> >this too please.

Personally, I have my doubts about this - I really have problems with
its scalability, and think, while it might work for one, or even two
options, it doesn't scale up beyond that.

> > Examples:
> > pkg_admin pmatch 'x>=1.0~a' x-1.0 ->false
> > pkg_admin pmatch 'x>=1.0~a' x-1.0~a ->true
> > pkg_admin pmatch 'x>=1.0~a' x-0.0~a ->false
> > 
> > pkg_admin pmatch 'x~!a' x-1.0~a ->false
> > pkg_admin pmatch 'x~!a' x-1.0 ->true
> > 
> > pkg_admin pmatch 'x~a+b' x-1.0 ->false
> > pkg_admin pmatch 'x~a+b' x-1.0~a ->false
> > 
> > pkg_admin pmatch 'x~*' x-1.0 ->true
> > pkg_admin pmatch 'x~*' x-1.0~a ->true
> > 
> > pkg_admin pmatch 'x~!*' x-1.0 ->true
> > pkg_admin pmatch 'x~!*' x-1.0~a ->false
> > 
> > etc.
> > 
> > Some remarks:
> > - The matching algorithm with patterns on boolean variables is in general a
> >   complex problem (known as SAT, I think), and the one implemented tries to
> >   keep things simple and intuitve. But it's not been formalized, so there 
> > must
> >   be some caveats ...
> > 
> > - As wiz@ already noted, the use of the not operator `!' might be replaced 
> > by a
> >   `^' to avoid quoting issues, and instead of using pkgname-version~options,
> >   one could also use pkgname~options-version?.

I have only ever seen ^ used as a negation or complement operator at
the start of character classes in regexps, which I think is an
esoteric case.  I also don't think that quoting should have any
bearing on this.
 
I'd prefer to see more discussion before anything gets committed.

Best,
Alistair