irrelevant package

Duncan Coutts duncan.coutts at worc.ox.ac.uk
Tue Jun 14 08:02:36 EDT 2005


On Mon, 2005-06-13 at 16:06 +0100, Simon Marlow wrote:
> This is "fixed" in newer versions of Cabal.
> 
> However, you are heading for problems here.  When you install a package
> P that includes a module M, you prevent the user from having any modules
> called M unless they say '-hide-package P' (see previous discussions on
> this subject).
> 
> For this reason, we strongly recommend using hierarchical module names.
> 
> At the moment, Cabal "exposes" all the packages it imports.  Perhaps we
> should have an option to install an unexposed package, to allow
> installation of packages that contain non-hierarchical module names.
> Isaac - what do you think?

But remember that any exposed dependent package of P effectively exposes
package P anyway. So it's not the case that you can install an unexposed
package and assume that it'll all be ok. Any package installed later can
come along and expose your package and you're back to the problem that
no programs/libs with your module M can now be complied (without several
-hide-package flags).

Duncan



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