Re: [Haskell-cafe] Package versioning policy - Harmless type changes?

Hi, Am Donnerstag, den 22.09.2011, 08:32 -0300 schrieb Felipe Almeida Lessa:

On Thu, Sep 22, 2011 at 7:37 AM, Heinrich Apfelmus wrote: Given that you are following the PVP, I would put the following constraint:

Build-depends: foo >= 0.1 && < 0.2

However, if someone with an older version of foo installed on their system tried to install my package, they would get a type error, since I haven't put a "Typeable a =>" context on my bar.

would you? I think you would use foo >= 0.1.3 && < 0.2, because 0.1.3 is allowed to have API additions that are not in 0.1.2, so if you develop your library against 0.1.3, there is no guarantee that foo was not empty in 0.1.2. Under this interpretation, removing a constraint should be equivalent to an API addition, hence rule 2 on http://www.haskell.org/haskellwiki/Package_versioning_policy#Version_numbers ought to apply. Greetings, Joachim -- Joachim "nomeata" Breitner mail@joachim-breitner.de | nomeata@debian.org | GPG: 0x4743206C xmpp: nomeata@joachim-breitner.de | http://www.joachim-breitner.de/