On 31/07/2014 15:31, Edward Z. Yang wrote:
We need to rethink the shadowing behaviour. It is designed to handle
the case where we have the same PackageId (name + version) in two
different DBs (e.g. global and local). Shadowing takes the topmost one
of these (e.g. local, or rightmost -package-db
> We need to rethink the shadowing behaviour. It is designed to handle
> the case where we have the same PackageId (name + version) in two
> different DBs (e.g. global and local). Shadowing takes the topmost one
> of these (e.g. local, or rightmost -package-db flag). We can relax this
> requ
Sorry for not replying to this earlier. I think after our meeting the
other day we agreed to keep the existing algorithm but document it
better. Here's a stab at describing the spec:
1. compute the set of valid packages, where a package is valid if
- all its dependencies are valid
- it is
Good question. I think package environments are the right answer here:
GHCi should come preloaded with some special global package environment.
Edward
Excerpts from John Lato's message of 2014-07-25 00:52:12 +0100:
> How would this work with ghci? If I'm understanding correctly, the
> proposal
How would this work with ghci? If I'm understanding correctly, the
proposal means users could no longer do:
$ ghci SomeFile.hs
and have it work without manually specifying all -package flags. Did I
miss something?
I think it would work in conjuction with the package environments stuff,
provi
Excerpts from Edward Z. Yang's message of 2014-07-24 15:57:05 +0100:
> - It assumes *-hide-all-packages* at the beginning. This scheme
> probably works less well without that: now we need some consistent
> view of the database to start with.
Actually, thinking about this, this dovetails nicel
-devs [mailto:ghc-devs-boun...@haskell.org] On Behalf Of
| Edward Z.Yang
| Sent: 24 July 2014 15:57
| To: ghc-devs
| Subject: Changing the -package dependency resolution algorithm
|
| Right now, GHC has a very complex and hard to explain algorithm for
| picking packages from the package database whe
Right now, GHC has a very complex and hard to explain algorithm for
picking packages from the package database when you give it a pile of
-package/-package-id/-{hide,ignore,trust,distrust}-package flags.
Roughly, it currently does something like this.
1. Concatenate all of the package databases in
