Proposed ghc-pkg and cabal feature

Dan Knapp dankna at
Mon Mar 15 21:25:17 EDT 2010

I came up with an idea for a small feature that I believe would make
a useful addition to ghc-pkg and Cabal.  I'm willing to implement it
myself, but I have had some previous experiences with other projects
where I did some work and then the maintainers said "sorry, not
interested", so I want to gauge interest before I start.

I've already posted to glasgow-haskell-users, where Simon Marlow
was kind enough to respond; he suggested that before starting work
I should also get people's opinions here.

The feature itself is this:  Arbitrary key-value pairs in Cabal
package files and the installed-package database.  The use-case is for
an application supporting plugins to discover installed plugins
compatible with it, interrogating these fields through the GHC API.

For example, my content-management system FruitTart could enumerate
the list of installed packages looking for packages which export a
field "fruit-tart-plugin-interface-version" with a numeric value
matching the interface version it's expecting.

Once again, I'm not asking anyone to do this work for me - I'm eager
to get my hands dirty and do it myself.  I just want to find out what
the process would be to get it accepted, once it works.

Thanks in advance,

Dan Knapp
"An infallible method of conciliating a tiger is to allow oneself to
be devoured." (Konrad Adenauer)

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