A dependent sum is a generalization of a
particular way of thinking about the Either
type. Either a b can be thought of as a
2-tuple (tag, value), where the value of the
tag determines the type of the value. In
particular, either tag = Left and value :: a
or tag = Right and value :: b.
This package allows you to define your own
dependent sum types by using your own "tag"
types.
Changes
Revision history for dependent-sum
0.7.1.0 - 2020-03-25
Shift version bounds for some to 1.0.1.* versions.
0.7.0.0 - 2020-03-24
Fix ChangeLog to include the breaking change in 0.6.2.1/0.6.2.2 and properly do major version bump to reflect the breaking change.
0.6.2.2 - 2020-03-23
Update GitHub repository in cabal metadata.
0.6.2.1 - 2020-03-21
(Breaking change) Removed modules Data.GADT.Compare, Data.GADT.Show, Data.Some and now re-export them from the some package. This forced some deprecations to be fully realized.
Update cabal meta-information (tested with GHC 8.8).
0.6.2.0 - 2019-08-04
Revert change that increased strictness of Data.Some.Some in 0.6.1
0.6.1.0 - 2019-08-04
Add legacy eqTagged and compareTagged functions. Fix deprecated OrdTag synonym (it was missing the Has' Eq constraint). To upgrade from dependent-sum <0.6, you will likely need to add enable the FlexibleContexts language extension, and possible others.
0.6 - 2019-03-21
Use constraints-extras ArgDict/Has’ to define the instances of Eq, Ord, Read and Show for DSum.
This obviates the need for the EqTag, OrdTag, ReadTag and ShowTag classes.
0.5.1.0
Add mkSome and mapSome to Data.Some.
Add GEq, GCompare, GShow, and GRead instances for Sum and Product (Except GRead (Product a b)).
Deprecate (:=) for (:~:) from Data.Type.Equality.
In GHC 7.8 and above, this is the same as (:~:).
But now we no longer support earlier GHCs, so there’s no point of the alias.
Remove support for GHC 7.x.
The git repositories for dependent-sum and dependent-sum-template are now the same, though the Haskell packages remain separate.
0.5.0.0
Make Some a newtype with associated pattern synonyms using unsafeCoerce
to avoid the GADT performance overhead. This shouldn’t affect users.
Deprecate the constructor name This in favor of Some.
