darcs patch: Add liftField and maybeField to ParseUti... (and 1 more)

[Bertram Felgenhauer]

Isaac Jones wrote:
> Duncan Coutts <duncan.coutts at worc.ox.ac.uk> writes:
> >> - fix the handling of 'x-' fields - with the previous patch cabal would
> >>   complain about these as unknown in most contexts
> 
> Right, it shouldn't ever complain / warn about x-fields, right?

Indeed. I had missed that parseBInfoField handled those.

> Cool.  I'm OK with it, but worried about Simon's patch that does the
> same thing.  Simon, can you tease out that patch in short order and
> compare it side-by-side w/ Bertram's?  Should we just go ahead and
> apply Bertram's?

I'm happy either way.  It's not an urgent change, it just seemed to be the
right thing to do, in order to add new library stanzas.

> So this is done w/ a field rather than a flag to configure, but it
> sounds more like a configure option in most cases, no?  Shouldn't this
> be up to the user more than the package author?  It should be a pretty
> rare package that's meant to be hidden by default.

I wanted this for lambdabot - it's a stand-alone application, but it's
plugin-based; one of the plugin's utilities (runplugs) has an auxillary
module (ShowQ) that's arguably not useful for general use. To install
it properly, a hidden package seemed to be the right thing.

And after refactoring the parsing of the package description adding
support for that to Distribution.Simple is a very simple change to Cabal.

> We could always have both a field and a configure flag.

That makes sense to me, actually.

regards,

Bertram