
Hi, Can we derive Data for Data.Version.Version? It would benefit Cabal. Thanks, David

+1 from me. I've had to use an orphan
Sent from my iPhone
On Mar 15, 2013, at 5:56 PM, David Lazar
Hi,
Can we derive Data for Data.Version.Version? It would benefit Cabal.
Thanks, David
_______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries

Hello *, As we're still in time to get this in before the GHC 7.8 freeze and this seems to be "the right thing" to do, are there any objections to implement this (specifically, adding a `deriving Data` to `base`s Data.Version for GHC 7.8.1)? Cheers, hvr On 2013-03-15 at 23:29:21 +0100, Edward A Kmett wrote:
+1 from me. I've had to use an orphan
Sent from my iPhone
On Mar 15, 2013, at 5:56 PM, David Lazar
wrote: Hi,
Can we derive Data for Data.Version.Version? It would benefit Cabal.
Thanks, David
_______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries
-- "Elegance is not optional" -- Richard O'Keefe

Please do! I've had to orphan that in a couple of projects.
-Edward
On Thu, Sep 12, 2013 at 7:24 AM, Herbert Valerio Riedel
Hello *,
As we're still in time to get this in before the GHC 7.8 freeze and this seems to be "the right thing" to do, are there any objections to implement this (specifically, adding a `deriving Data` to `base`s Data.Version for GHC 7.8.1)?
Cheers, hvr
On 2013-03-15 at 23:29:21 +0100, Edward A Kmett wrote:
+1 from me. I've had to use an orphan
Sent from my iPhone
On Mar 15, 2013, at 5:56 PM, David Lazar
wrote: Hi,
Can we derive Data for Data.Version.Version? It would benefit Cabal.
Thanks, David
_______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries
-- "Elegance is not optional" -- Richard O'Keefe

If the instances are hand-rolled in base, you'll need:
instance Data Version where
gfoldl k z (Version bs ts) = z Version `k` bs `k` ts
gunfold k z c = case constrIndex c of
1 -> k (k (z Version))
_ -> error "Data.Data.gunfold(Version)"
toConstr (Version _ _) = versionConstr
dataTypeOf _ = versionType
versionConstr :: ConstrversionConstr = mkConstr versionType "Version"
["versionBranch","versionTags"] Prefix
versionType :: DataTypeversionType = mkDataType "Data.Version.Version"
[versionConstr]
On Thu, Sep 12, 2013 at 7:24 AM, Herbert Valerio Riedel
Hello *,
As we're still in time to get this in before the GHC 7.8 freeze and this seems to be "the right thing" to do, are there any objections to implement this (specifically, adding a `deriving Data` to `base`s Data.Version for GHC 7.8.1)?
Cheers, hvr
On 2013-03-15 at 23:29:21 +0100, Edward A Kmett wrote:
+1 from me. I've had to use an orphan
Sent from my iPhone
On Mar 15, 2013, at 5:56 PM, David Lazar
wrote: Hi,
Can we derive Data for Data.Version.Version? It would benefit Cabal.
Thanks, David
_______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries
-- "Elegance is not optional" -- Richard O'Keefe
participants (4)
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David Lazar
-
Edward A Kmett
-
Edward Kmett
-
Herbert Valerio Riedel