Meaning of version tags in cabal files
I noticed that cabal will parse, but ignore, version tags. For example, the two lines appear to be equivalent in how a package gets built: Version: 1.1Version: 1.1-alternate Arguably this is not the right thing to do, as it changes the semantics of versions. For example, I can install version 1.1 of a package without replacing version 1.0, but if I try to install version 1.0-alternate, I will actually replace version 1.0. I'm not against discarding version tags, but I'd like to know if there's a rationale for _silently_ discarding them. -heatsink _________________________________________________________________ Hotmail: Trusted email with Microsoft’s powerful SPAM protection. http://clk.atdmt.com/GBL/go/196390706/direct/01/
red5_2:
I noticed that cabal will parse, but ignore, version tags. For example, the two lines appear to be equivalent in how a package gets built:
Version: 1.1 Version: 1.1-alternate
Arguably this is not the right thing to do, as it changes the semantics of versions. For example, I can install version 1.1 of a package without replacing version 1.0, but if I try to install version 1.0-alternate, I will actually replace version 1.0.
I'm not against discarding version tags, but I'd like to know if there's a rationale for _silently_ discarding them.
Version tags are not supported by Cabal or Hackage or any of the Haskell tools, afaik. See the package version policy for the conventions we follow: http://www.haskell.org/haskellwiki/Package_versioning_policy
On Mon, 2010-01-18 at 21:41 +0000, C Rodrigues wrote:
I noticed that cabal will parse, but ignore, version tags.
Yes.
Arguably this is not the right thing to do, as it changes the semantics of versions.
It's precisely because the semantics of version tags is so useless (and inconsistent) that we stopped using them.
I'm not against discarding version tags, but I'd like to know if there's a rationale for _silently_ discarding them.
We've not yet removed tag from the parser for backwards compatibility. Clearly what we should do is add a big warning (or simply error) that such tags are no longer supported. I hope in time to get Data.Version changed to eliminate the tags entirely. Duncan
participants (3)
-
C Rodrigues -
Don Stewart -
Duncan Coutts