Add a new function registerInState to EraTransition

... which allows to inject transition configuration data in the given
`NewEpochState`.

This change allows the Ledger to define this logic in this component
without needing to do it in the Consensus layer. In this way, we
improve the separation of concerns.

Author: dnadales

eras/allegra/impl/src/Cardano/Ledger/Allegra/Transition.hs

@@ -22,6 +22,8 @@ instance Crypto c => EraTransition (AllegraEra c) where
 
   mkTransitionConfig () = AllegraTransitionConfig
 
+  registerInState = registerInitialFundsThenStaking
+
   tcPreviousEraConfigL =
     lens atcShelleyTransitionConfig (\atc pc -> atc {atcShelleyTransitionConfig = pc})
 

eras/alonzo/impl/src/Cardano/Ledger/Alonzo/Transition.hs

@@ -41,6 +41,8 @@ instance Crypto c => EraTransition (AlonzoEra c) where
 
   mkTransitionConfig = AlonzoTransitionConfig
 
+  registerInState = registerInitialFundsThenStaking
+
   tcPreviousEraConfigL =
     lens atcMaryTransitionConfig (\atc pc -> atc {atcMaryTransitionConfig = pc})
 

eras/babbage/impl/src/Cardano/Ledger/Babbage/Transition.hs

@@ -23,6 +23,8 @@ instance Crypto c => EraTransition (BabbageEra c) where
 
   mkTransitionConfig () = BabbageTransitionConfig
 
+  registerInState = registerInitialFundsThenStaking
+
   tcPreviousEraConfigL =
     lens btcAlonzoTransitionConfig (\btc pc -> btc {btcAlonzoTransitionConfig = pc})
 

eras/conway/impl/src/Cardano/Ledger/Conway/Transition.hs

@@ -72,6 +72,15 @@ class EraTransition era => ConwayEraTransition era where
 
   tcConwayGenesisL :: Lens' (TransitionConfig era) (ConwayGenesis (EraCrypto era))
 
+registerDRepsThenDelegs ::
+  ConwayEraTransition era =>
+  TransitionConfig era ->
+  NewEpochState era ->
+  NewEpochState era
+registerDRepsThenDelegs cfg =
+  -- NOTE: The order of registration does not matter.
+  registerDelegs cfg . registerInitialDReps cfg
+
 instance Crypto c => EraTransition (ConwayEra c) where
   data TransitionConfig (ConwayEra c) = ConwayTransitionConfig
     { ctcConwayGenesis :: !(ConwayGenesis c)
@@ -81,6 +90,10 @@ instance Crypto c => EraTransition (ConwayEra c) where
 
   mkTransitionConfig = ConwayTransitionConfig
 
+  registerInState cfg =
+    registerDRepsThenDelegs cfg
+      . registerInitialFundsThenStaking cfg
+
   tcPreviousEraConfigL =
     lens ctcBabbageTransitionConfig (\ctc pc -> ctc {ctcBabbageTransitionConfig = pc})
 

eras/mary/impl/src/Cardano/Ledger/Mary/Transition.hs

@@ -23,6 +23,8 @@ instance Crypto c => EraTransition (MaryEra c) where
 
   mkTransitionConfig () = MaryTransitionConfig
 
+  registerInState = registerInitialFundsThenStaking
+
   tcPreviousEraConfigL =
     lens mtcAllegraTransitionConfig (\mtc pc -> mtc {mtcAllegraTransitionConfig = pc})
 

eras/shelley/impl/src/Cardano/Ledger/Shelley/Transition.hs

@@ -25,6 +25,7 @@ module Cardano.Ledger.Shelley.Transition (
   mkShelleyTransitionConfig,
   createInitialState,
   registerInitialFunds,
+  registerInitialFundsThenStaking,
   registerInitialStaking,
   toShelleyTransitionConfigPairs,
   protectMainnet,
@@ -85,6 +86,16 @@ class
     TransitionConfig (PreviousEra era) ->
     TransitionConfig era
 
+  registerInState ::
+    -- | Extract data from the given transition configuration and store it in the given state.
+    --
+    -- FIXME: Are there any other contextual consideration we need to comment on here?
+    --
+    -- FIXME: Perhaps 'injectInState' is a more fitting name?
+    TransitionConfig era ->
+    NewEpochState era ->
+    NewEpochState era
+
   -- | In case when a previous era is available, we should always be able to access
   -- `TransitionConfig` for the previous era, from within the current era's
   -- `TransitionConfig`
@@ -130,6 +141,16 @@ class
 tcNetworkIDG :: EraTransition era => SimpleGetter (TransitionConfig era) Network
 tcNetworkIDG = tcShelleyGenesisL . to sgNetworkId
 
+registerInitialFundsThenStaking ::
+  EraTransition era =>
+  TransitionConfig era ->
+  NewEpochState era ->
+  NewEpochState era
+registerInitialFundsThenStaking cfg =
+  -- We must first register the initial funds, because the stake
+  -- information depends on it.
+  registerInitialStaking cfg . registerInitialFunds cfg
+
 instance Crypto c => EraTransition (ShelleyEra c) where
   newtype TransitionConfig (ShelleyEra c) = ShelleyTransitionConfig
     { stcShelleyGenesis :: ShelleyGenesis c
@@ -139,6 +160,8 @@ instance Crypto c => EraTransition (ShelleyEra c) where
   mkTransitionConfig =
     error "Impossible: There is no EraTransition instance for ByronEra"
 
+  registerInState = registerInitialFundsThenStaking
+
   tcPreviousEraConfigL = notSupportedInThisEraL
 
   tcTranslationContextL =

libs/cardano-ledger-api/src/Cardano/Ledger/Api/Transition.hs

@@ -21,6 +21,7 @@ module Cardano.Ledger.Api.Transition (
   tcInitialFundsL,
   tcInitialStakingL,
   createInitialState,
+  registerInState,
   registerInitialFunds,
   registerInitialStaking,
   registerInitialDReps,