On 6/23/10 8:06 PM, Duncan Coutts wrote:
Consider an example where we want to avoid using two versions of a dependency:
The htar program depends on the tar and zlib packages. The tar and
zlib packages depend on bytestring. Both tar and zlib export functions
that use the type ByteString. The htar program takes composes
functions from the two packages together, passing a bytestring from
one to the other.
Okay, I hadn't considered this, though it seems like the real problem in
this situation is that someone violated the package version policy: if
tar is upgraded to use a newer, incompatible version of bytestring, then
it should have an appropriate version bump that causes htar to ignore
the new version and use the older version instead.
I am getting the impression from these discussions that what we really
need in the long term to solve a lot of these problems is to enforce the
package versioning policy.
Cheers,
Greg
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
