Implementing instances for monad transformer stacks can be tedious.
mtl defines each instance for each
transfomer, but this can be avoided.
Elevator let's you access instances of the underlying monad of a transformer.
Composing transformers with ComposeT brings instances into scope during the
initialization of a transformer stack.
Elevator can be used with DerivingVia to select a specific transformer to
derive instances for a transformer stack.
ComposeT composes transformers and accumulates instances in a transformer
stack.
Changes
Revision history for deriving-trans
0.9.1.0 12 Jul 2023
Support new optional dependency monad-logger >= 0.3.38.
Add MonadLogger and MonadLoggerIO instances to Elevator and ComposeT.
Add MonadLogger and MonadLoggerIO “base-case” instances for LoggingT, NoLoggingT and WriterLoggingT.
0.9.0.0 05 Jul 2023
Drop support for GHC < 9.6.
0.8.1.0 20 Feb 2023
Support new optional dependency logict >= 0.8.0.0.
Add MonadLogic instances to Elevator and ComposeT including a LogicT “base-case” instance.
Add MonadMask instances to Elevator and ComposeT including a CatchT “base-case” instance.
Add MonadPlus “base-case” instances for ExceptT, MaybeT, CatchT and LogicT.
0.8.0.0 31 Jan 2023
Update version boundaries of dependencies:
monad-control >= 1.0.3
monad-control-identity >= 0.2.0.0
transformers-base >= 0.4.6
primitive >= 0.7.1.0
unliftio-core >= 0.2.0.0
Add common instances to ComposeT:
Alternative (recursive and “base-case”)
MonadFail (recursive and “base-case”)
MonadFix (recursive; didn’t find any “base-case”)
MonadPlus (determined by Alternative)
MonadZip (recursive; didn’t find any “base-case”)
0.7.0.0 31 Jan 2023
Update required version bounds for exceptions to >= 0.10.5.
Remove redundant MonadIO constraints from instances StatefulGen, FrozenGen and RandomGenM.
Drop support for GHC < 9.2.
0.6.1.0 27 Jan 2023
Add optional dependency random >= 1.2.
Add StatefulGen, FrozenGen and RandomGenM instances to Elevator and ComposeT.
There are no “base-case” instances because there are no related transformers, just base monads.
0.6.0.0 23 Jan 2023
Update dependencies:
transformers >= 0.6
exceptions >= 0.4 (optional)
mtl >= 2.3 (optional)
primitive (optional)
resourcet >= 1.2 (optional)
unliftio (optional)
Add MonadAccum and MonadSelect instances to Elevator and ComposeT.
Add “base-case” instances for AccumT and SelectT.
Add “base-case” instances for the CPS versions of WriterT and RWST.
Remove Monad m constraint from “base-case” instance for ContT.
Add MonadResource instances to Elevator and ComposeT including a ResourceT “base-case” instance.
0.5.2.0 17 Jan 2023
Add optional dependency primitive.
Add MonadPrim instances to Elevator and ComposeT.
0.5.1.0 11 Jan 2023
Introduce cabal flags exceptions, mtl and unliftio.
These flags enable the dependency on additional optional packages, to reduce the requirement of orphan instances.
Add MonadUnliftIO instances to Elevator and ComposeT.
Add MonadThrow and MonadCatch instances to Elevator and ComposeT.
Add MonadThrow and MonadCatch “base-case” instances for CatchT to ComposeT.
