[Haskell] Re: Trying to install binary-0.4
igloo at earth.li
Wed Oct 17 15:28:07 EDT 2007
On Wed, Oct 17, 2007 at 01:28:45AM +0100, Duncan Coutts wrote:
> On Wed, 2007-10-17 at 00:35 +0100, Ian Lynagh wrote:
> > package foo:
> > module Foo where
> > data T
> > package bar:
> > module Bar where
> > bar :: T
> > package baz:
> > module Baz where
> > baz :: T -> ()
> > then
> > baz bar
> > might be a type error if I have multiple versions of foo installed and
> > bar and baz have been compiled against different versions.
> Sure, those are not compatible. But we can detect that just by looking
> at the dependencies of each package.
In general it is possible to have 2 different versions of a package in a
single program, though, e.g. bar and baz could internally use different
versions of a binary-tree package.
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