Changelog for singletons-2.6

Changelog for singletons project











Fix bug #116, thus allowing locally-declared symbols to be used in GHC 7.10.



Update testsuite to work with th-desugar-1.5.2. No functional changes.


This is a maintenance release to support building (but not testing, due to GHC bug #10058) with 7.10. This release also targets th-desugar-1.5. Some types changed (using th-desugar's new DsMonad instead of Quasi), but clients generally won't need to make any changes, unless they, too, generalize over Quasi.


This is a complete rewrite of the package.

This release can be seen as a "technology preview". More features are coming soon.

This version drops GHC 7.6 support.


Template Haskell names are now more hygienic. In other words, singletons won't try to gobble up something happened to be named Sing in your project. (Note that the Template Haskell names are not completely hygienic; names generated during singleton generation can still cause conflicts.)

If a function to be promoted or singletonized is missing a type signature, that is now an error, not a warning.

Added a new external module Data.Singletons.TypeLits, which contain the singletons for GHC.TypeLits. Some convenience functions are also provided.

The extension EmptyCase is no longer needed. This caused pain when trying to support both GHC 7.6.3 and 7.8.


Fix export list of Data.Singletons.TH, again again.

Add SEq instances for Nat and Symbol.


Fix export list of Data.Singletons.TH, again.


Fix export list of Data.Singletons.TH.


Make compatible with GHC HEAD, but HEAD reports core lint errors sometimes.

Change module structure significantly. If you want to derive your own singletons, you should import Data.Singletons.TH. The module Data.Singletons now exports functions only for the use of singletons.

New modules Data.Singletons.Bool, ...Maybe, ...Either, and ...List are just like their equivalents from Data., except for List, which is quite lacking in features.

For singleton equality, use Data.Singletons.Eq.

For propositional singleton equality, use Data.Singletons.Decide.

New module Data.Singletons.Prelude is meant to mirror the Haskell Prelude, but with singleton definitions.

Streamline representation of singletons, resulting in exponential speedup at execution. (This has not been rigorously measured, but the data structures are now exponentially smaller.)

Add internal support for TypeLits, because the TypeLits module no longer exports singleton definitions.

Add support for existential singletons, through the toSing method of SingKind.

Remove the SingE class, bundling its functionality into SingKind. Thus, the SingRep synonym has also been removed.

Name change: KindIs becomes KProxy.

Add support for singletonizing calls to error.

Add support for singletonizing empty data definitions.


Make compatible with GHC HEAD, but HEAD reports core lint errors sometimes.


Bug fix to make singletons compatible with GHC 7.6.1.

Added git info to cabal file.


Update to work with latest version of GHC (7.7.20130114).

Now use branched type family instances to allow for promotion of functions with overlapping patterns.

Permit promotion of functions with constraints by omitting constraints.


Update to work with latest version of GHC (7.7.20121031).

Removed use of Any to simulate kind classes; now using KindOf and OfKind from GHC.TypeLits.

Made compatible with GHC.TypeLits.


Added this changelog

Update to work with latest version of GHC (7.6.1). (There was a change to Template Haskell).

Moved library into Data.Singletons.


Update to work with latest version of GHC. (There was a change to Template Haskell).

Updated dependencies in cabal to include the newer version of TH.


Initial public release