Remove unused functions (#1762)

Every function that is not used in this codebase has been removed, with
the few exceptions listed in the weeder roots.

A weeder check has been added to ensure no unused functions sneak back
in.

Anything that is actually really needed can either be readded from
history, or upstreamed to a library or form a new library so that it can
be discovered in hoogle.

---

<!-- Consider each and tick it off one way or the other -->
* [ ] CHANGELOG updated or not needed
* [ ] Documentation updated or not needed
* [ ] Haddocks updated or not needed
* [ ] No new TODOs introduced or explained herafter

.github/workflows/weeder.yaml

@@ -0,0 +1,33 @@
+name: Check code weeds
+
+on:
+  # We're using merge-chains; so this needs to run then.
+  merge_group:
+  pull_request:
+
+jobs:
+  weeder:
+    name: Check code weeds
+    runs-on: ubuntu-latest
+    steps:
+    - name: 📥 Checkout repository
+      uses: actions/checkout@v4
+
+    - name: ❄ Prepare nix
+      uses: cachix/install-nix-action@v30
+      with:
+        extra_nix_config: |
+          accept-flake-config = true
+          log-lines = 1000
+
+    - name: ❄ Cachix cache of nix derivations
+      uses: cachix/cachix-action@v15
+      with:
+        name: cardano-scaling
+        authToken: '${{ secrets.CACHIX_CARDANO_SCALING_AUTH_TOKEN }}'
+
+    - name: 📐 Check weeder
+      run: |
+        nix develop --command -- bash -c "cabal update"
+        nix develop --command -- bash -c "cabal build all"
+        nix develop --command -- bash -c "weeder --require-hs-files"

hydra-cardano-api/hydra-cardano-api.cabal

@@ -50,7 +50,6 @@ library
     Hydra.Cardano.Api.CtxUTxO
     Hydra.Cardano.Api.ExecutionUnits
     Hydra.Cardano.Api.Hash
-    Hydra.Cardano.Api.KeyWitness
     Hydra.Cardano.Api.Network
     Hydra.Cardano.Api.NetworkId
     Hydra.Cardano.Api.PlutusScript

hydra-cardano-api/src/Cardano/Api/UTxO.hs

@@ -83,20 +83,10 @@ render :: (TxIn, TxOut ctx era) -> Text
 render (k, TxOut _ (txOutValueToValue -> v) _ _) =
   T.drop 54 (renderTxIn k) <> " ↦ " <> renderValue v
 
--- | Select the minimum (by TxIn) utxo entry from the UTxO map.
---
--- This function is partial.
-min :: UTxO -> UTxO
-min = UTxO . uncurry Map.singleton . Map.findMin . toMap
-
 -- | Remove the right hand side from the left hand side.
 difference :: UTxO' out -> UTxO' out -> UTxO' out
 difference a b = UTxO $ Map.difference (toMap a) (toMap b)
 
--- | Infix version of 'difference'.
-(\\) :: UTxO' out -> UTxO' out -> UTxO' out
-a \\ b = difference a b
-
 -- * Type Conversions
 
 -- | Transforms a UTxO containing tx outs from any era into Babbage era.

hydra-cardano-api/src/Hydra/Cardano/Api.hs

@@ -130,7 +130,6 @@ import Hydra.Cardano.Api.CtxTx as Extras
 import Hydra.Cardano.Api.CtxUTxO as Extras
 import Hydra.Cardano.Api.ExecutionUnits as Extras
 import Hydra.Cardano.Api.Hash as Extras
-import Hydra.Cardano.Api.KeyWitness as Extras
 import Hydra.Cardano.Api.NetworkId ()
 import Hydra.Cardano.Api.PlutusScript as Extras
 import Hydra.Cardano.Api.PolicyId as Extras

hydra-cardano-api/src/Hydra/Cardano/Api/ExecutionUnits.hs

@@ -9,7 +9,3 @@ import Cardano.Ledger.Alonzo.Scripts qualified as Ledger
 -- | Convert a cardano-api 'ExecutionUnits' into a cardano-ledger 'ExUnits'
 toLedgerExUnits :: ExecutionUnits -> Ledger.ExUnits
 toLedgerExUnits = toAlonzoExUnits
-
--- | Convert a cardano-ledger 'ExUnits' into a cardano-api 'ExecutionUnits'
-fromLedgerExUnits :: Ledger.ExUnits -> ExecutionUnits
-fromLedgerExUnits = fromAlonzoExUnits

hydra-cardano-api/src/Hydra/Cardano/Api/Hash.hs

@@ -5,7 +5,6 @@ import Hydra.Cardano.Api.Prelude
 import Cardano.Ledger.Keys qualified as Ledger
 import Cardano.Ledger.Plutus.TxInfo (transKeyHash)
 import Cardano.Ledger.SafeHash (unsafeMakeSafeHash)
-import Cardano.Ledger.Shelley.Scripts qualified as Ledger
 import Data.ByteString qualified as BS
 import PlutusLedgerApi.V3 qualified as Plutus
 
@@ -33,22 +32,6 @@ unsafePaymentKeyHashFromBytes bytes
   | otherwise =
       PaymentKeyHash $ Ledger.KeyHash $ unsafeHashFromBytes bytes
 
--- | Unsafe wrap some bytes as a 'ScriptHash', relying on the fact that Plutus
--- is using Blake2b_224 for hashing data (according to 'cardano-ledger').
---
--- Pre-condition: the input bytestring MUST be of length 28.
-unsafeScriptHashFromBytes ::
-  HasCallStack =>
-  ByteString ->
-  ScriptHash
-unsafeScriptHashFromBytes bytes
-  | BS.length bytes /= 28 =
-      error $ "unsafeScriptHashFromBytes: pre-condition failed: " <> show (BS.length bytes) <> " bytes."
-  | otherwise =
-      fromShelleyScriptHash
-        . Ledger.ScriptHash
-        $ unsafeHashFromBytes bytes
-
 -- | Unsafe wrap some bytes as a 'Hash ScriptData', relying on the fact that
 -- Plutus is using Blake2b_256 for hashing data (according to 'cardano-ledger').
 --

hydra-cardano-api/src/Hydra/Cardano/Api/PlutusScript.hs

@@ -4,30 +4,12 @@ module Hydra.Cardano.Api.PlutusScript where
 
 import Hydra.Cardano.Api.Prelude
 
-import Cardano.Ledger.Alonzo.Scripts qualified as Ledger
-import Cardano.Ledger.Plutus.Language qualified as Ledger
 import Data.ByteString.Short qualified as SBS
 import PlutusLedgerApi.Common qualified as Plutus
 import Test.QuickCheck (listOf)
 
 -- * Type Conversions
 
--- | Convert a cardano-ledger 'Script' into a cardano-api 'PlutusScript'
---
--- NOTE: This function is unsafe in two manners:
---
--- (a) If the given script is a timelock script, it throws an impure exception;
--- (b) If the given script is in a wrong language, it silently coerces it.
-fromLedgerScript ::
-  ( HasCallStack
-  , Ledger.AlonzoEraScript era
-  ) =>
-  Ledger.AlonzoScript era ->
-  PlutusScript lang
-fromLedgerScript = \case
-  Ledger.TimelockScript{} -> error "fromLedgerScript: TimelockScript"
-  Ledger.PlutusScript x -> Ledger.withPlutusScript x (\(Ledger.Plutus (Ledger.PlutusBinary bytes)) -> PlutusScriptSerialised bytes)
-
 -- | Convert a serialized plutus script into a cardano-api 'PlutusScript'.
 fromPlutusScript :: Plutus.SerialisedScript -> PlutusScript lang
 fromPlutusScript =

hydra-cardano-api/src/Hydra/Cardano/Api/PolicyId.hs

@@ -5,7 +5,6 @@ module Hydra.Cardano.Api.PolicyId where
 import Hydra.Cardano.Api.Prelude
 
 import Cardano.Ledger.Alonzo.Plutus.TxInfo qualified as Ledger
-import Cardano.Ledger.Hashes qualified as Ledger
 import Cardano.Ledger.Mary.Value qualified as Ledger
 import Hydra.Cardano.Api.ScriptHash ()
 import PlutusLedgerApi.V3 (CurrencySymbol, fromBuiltin, unCurrencySymbol)
@@ -17,9 +16,6 @@ instance Arbitrary PolicyId where
 
 -- * Type conversions
 
-toLedgerScriptHash :: PolicyId -> Ledger.ScriptHash StandardCrypto
-toLedgerScriptHash (PolicyId scriptHash) = toShelleyScriptHash scriptHash
-
 -- | Convert Cardano api 'PolicyId' to Cardano ledger `PolicyID`.
 toLedgerPolicyID :: PolicyId -> Ledger.PolicyID StandardCrypto
 toLedgerPolicyID (PolicyId sh) = Ledger.PolicyID (toShelleyScriptHash sh)

hydra-cardano-api/src/Hydra/Cardano/Api/Pretty.hs

@@ -13,7 +13,7 @@ import Cardano.Ledger.SafeHash qualified as Ledger
 import Data.Aeson qualified as Aeson
 import Data.ByteString.Lazy qualified as BL
 import Data.Function (on)
-import Data.List (intercalate, sort, sortBy)
+import Data.List (sort, sortBy)
 import Data.Map.Strict qualified as Map
 import Data.Text qualified as T
 import GHC.IsList (IsList (..))
@@ -23,9 +23,6 @@ import Hydra.Cardano.Api.ScriptData (fromLedgerData)
 renderTx :: Api.Tx -> String
 renderTx = renderTxWithUTxO mempty
 
-renderTxs :: [Api.Tx] -> String
-renderTxs xs = intercalate "\n\n" (renderTx <$> xs)
-
 -- | Like 'renderTx', but uses the given UTxO to resolve inputs.
 renderTxWithUTxO :: UTxO -> Api.Tx -> String
 renderTxWithUTxO utxo (Tx body _wits) =

hydra-cardano-api/src/Hydra/Cardano/Api/ScriptData.hs

@@ -4,15 +4,13 @@ module Hydra.Cardano.Api.ScriptData where
 
 import Hydra.Cardano.Api.Prelude hiding (left)
 
-import Cardano.Ledger.Alonzo.TxWits qualified as Ledger
 import Cardano.Ledger.Era qualified as Ledger
 import Cardano.Ledger.Plutus.Data qualified as Ledger
 import Codec.Serialise (deserialiseOrFail, serialise)
 import Control.Arrow (left)
 import Data.Aeson (Value (String), withText)
 import Data.ByteString qualified as BS
 import Data.ByteString.Base16 qualified as Base16
-import Data.Map qualified as Map
 import PlutusLedgerApi.V3 qualified as Plutus
 import Test.QuickCheck (arbitrarySizedNatural, choose, oneof, scale, sized, vector)
 
@@ -36,39 +34,14 @@ fromScriptData =
   Plutus.fromData . toPlutusData . getScriptData
 
 -- | Get the 'HashableScriptData' associated to the a 'TxOut'. Note that this
--- requires the 'CtxTx' context. To get script data in a 'CtxUTxO' context, see
--- 'lookupScriptData'.
+-- requires the 'CtxTx' context.
 txOutScriptData :: TxOut CtxTx era -> Maybe HashableScriptData
 txOutScriptData (TxOut _ _ d _) =
   case d of
     TxOutDatumInTx _ sd -> Just sd
     TxOutDatumInline _ sd -> Just sd
     _ -> Nothing
 
--- | Lookup included datum of given 'TxOut'.
-lookupScriptData ::
-  forall era.
-  ( UsesStandardCrypto era
-  , Ledger.Era (ShelleyLedgerEra era)
-  ) =>
-  Tx era ->
-  TxOut CtxUTxO era ->
-  Maybe HashableScriptData
-lookupScriptData (Tx (ShelleyTxBody _ _ _ scriptsData _ _) _) (TxOut _ _ datum _) =
-  case datum of
-    TxOutDatumNone ->
-      Nothing
-    (TxOutDatumHash _ (ScriptDataHash h)) ->
-      fromLedgerData <$> Map.lookup h datums
-    (TxOutDatumInline _ dat) ->
-      Just dat
- where
-  datums :: Map (Ledger.DataHash StandardCrypto) (Ledger.Data (ShelleyLedgerEra era))
-  datums =
-    case (scriptsData :: TxBodyScriptData era) of
-      TxBodyNoScriptData -> mempty
-      TxBodyScriptData _ (Ledger.TxDats m) _ -> m
-
 -- * Type Conversions
 
 -- | Convert a cardano-ledger script 'Data' into a cardano-api 'ScriptDatum'.

hydra-cardano-api/src/Hydra/Cardano/Api/ScriptHash.hs

@@ -4,19 +4,10 @@ module Hydra.Cardano.Api.ScriptHash where
 
 import Hydra.Cardano.Api.Prelude
 
-import Cardano.Ledger.Credential qualified as Ledger
 import Hydra.Cardano.Api.PlutusScript ()
 
 -- * Extras
 
--- | Extract the payment part of an address, as a script hash.
-getPaymentScriptHash :: AddressInEra era -> Maybe ScriptHash
-getPaymentScriptHash = \case
-  AddressInEra _ (ShelleyAddress _ (Ledger.ScriptHashObj h) _) ->
-    Just (fromShelleyScriptHash h)
-  _ ->
-    Nothing
-
 -- | Like 'hashScript', but for a 'ScriptInAnyLang'.
 hashScriptInAnyLang :: ScriptInAnyLang -> ScriptHash
 hashScriptInAnyLang (ScriptInAnyLang _ script) =

hydra-cardano-api/src/Hydra/Cardano/Api/Tx.hs

@@ -10,23 +10,13 @@ where
 import Hydra.Cardano.Api.Prelude
 
 import Cardano.Api.UTxO qualified as UTxO
-import Cardano.Ledger.Alonzo.TxWits qualified as Ledger
 import Cardano.Ledger.Api (
   EraTx (mkBasicTx),
-  bodyTxL,
-  datsTxWitsL,
-  getLanguageView,
   inputsTxBodyL,
   mkBasicTxBody,
-  rdmrsTxWitsL,
-  scriptIntegrityHashTxBodyL,
-  witsTxL,
  )
 import Cardano.Ledger.Api qualified as Ledger
-import Cardano.Ledger.Babbage.Tx (hashScriptIntegrity)
-import Cardano.Ledger.Coin (Coin (..))
-import Cardano.Ledger.Plutus.Language qualified as Ledger
-import Control.Lens ((&), (.~), (^.))
+import Control.Lens ((&), (.~))
 import Data.Bifunctor (bimap)
 import Data.Functor ((<&>))
 import Data.Set qualified as Set
@@ -68,12 +58,6 @@ utxoProducedByTx tx =
  where
   TxBody body = getTxBody tx
 
--- | Get explicit fees allocated to a transaction.
-txFee' :: Tx era -> Coin
-txFee' (getTxBody -> TxBody body) =
-  case txFee body of
-    TxFeeExplicit _ y -> y
-
 -- * Type Conversions
 
 -- | Convert a cardano-api 'Tx' into a matching cardano-ledger 'Tx'.
@@ -89,19 +73,3 @@ fromLedgerTx ::
   Tx era
 fromLedgerTx =
   ShelleyTx shelleyBasedEra
-
--- | Compute the integrity hash of a transaction using a list of plutus languages.
-recomputeIntegrityHash ::
-  (Ledger.AlonzoEraPParams ppera, Ledger.AlonzoEraTxWits txera, Ledger.AlonzoEraTxBody txera, EraTx txera) =>
-  Ledger.PParams ppera ->
-  [Ledger.Language] ->
-  Ledger.Tx txera ->
-  Ledger.Tx txera
-recomputeIntegrityHash pp languages tx = do
-  tx & bodyTxL . scriptIntegrityHashTxBodyL .~ integrityHash
- where
-  integrityHash =
-    hashScriptIntegrity
-      (Set.fromList $ getLanguageView pp <$> languages)
-      (tx ^. witsTxL . rdmrsTxWitsL)
-      (tx ^. witsTxL . datsTxWitsL)