Add Hashable instances for UPLC Term and related types (#5629)

plutus-core/changelog.d/20231111_160632_unsafeFixIO_hash.md

@@ -0,0 +1,3 @@
+### Added
+
+- `Hashable` instances for `Data`, UPLC `Term` and related types.

plutus-core/plutus-core/src/PlutusCore/Crypto/BLS12_381/G1.hs

@@ -28,6 +28,7 @@ import Text.PrettyBy (PrettyBy)
 import Control.DeepSeq (NFData, rnf, rwhnf)
 import Data.ByteString (ByteString, length)
 import Data.Coerce (coerce)
+import Data.Hashable
 import Data.Proxy (Proxy (..))
 import Flat
 import Prettyprinter
@@ -65,6 +66,9 @@ instance Flat Element where
 instance NFData Element where
     rnf (Element x) = rwhnf x  -- Just to be on the safe side.
 
+instance Hashable Element where
+    hashWithSalt salt = hashWithSalt salt . compress
+
 -- | Add two G1 group elements
 {-# INLINE add #-}
 add :: Element -> Element -> Element

plutus-core/plutus-core/src/PlutusCore/Crypto/BLS12_381/G2.hs

@@ -28,6 +28,7 @@ import Text.PrettyBy (PrettyBy)
 import Control.DeepSeq (NFData, rnf, rwhnf)
 import Data.ByteString (ByteString, length)
 import Data.Coerce (coerce)
+import Data.Hashable
 import Data.Proxy (Proxy (..))
 import Flat
 import Prettyprinter
@@ -51,6 +52,9 @@ instance Flat Element where
 instance NFData Element where
     rnf (Element x) = rwhnf x  -- Just to be on the safe side.
 
+instance Hashable Element where
+    hashWithSalt salt = hashWithSalt salt . compress
+
 -- | Add two G2 group elements
 {-# INLINE add #-}
 add :: Element -> Element -> Element

plutus-core/plutus-core/src/PlutusCore/Crypto/BLS12_381/Pairing.hs

@@ -21,6 +21,7 @@ import Text.PrettyBy (PrettyBy, prettyBy)
 
 import Control.DeepSeq (NFData, rnf)
 import Data.Coerce (coerce)
+import Data.Hashable
 import Flat
 import Prettyprinter
 
@@ -49,6 +50,9 @@ instance Flat MlResult where
 instance NFData MlResult where
     rnf _ = ()
 
+instance Hashable MlResult where
+    hashWithSalt salt = const salt
+
 millerLoop :: G1.Element -> G2.Element -> MlResult
 millerLoop = coerce BlstBindings.millerLoop
 

plutus-core/plutus-core/src/PlutusCore/Data.hs

@@ -22,6 +22,7 @@ import Data.ByteString qualified as BS
 import Data.ByteString.Base64 qualified as Base64
 import Data.ByteString.Lazy qualified as BSL
 import Data.Data qualified
+import Data.Hashable
 import Data.Text.Encoding qualified as Text
 import Data.Word (Word64, Word8)
 import GHC.Generics
@@ -44,7 +45,7 @@ data Data =
     | I Integer
     | B BS.ByteString
     deriving stock (Show, Eq, Ord, Generic, Data.Data.Data)
-    deriving anyclass (NFData, NoThunks)
+    deriving anyclass (Hashable, NFData, NoThunks)
 
 instance Pretty Data where
     pretty = \case

plutus-core/plutus-core/src/PlutusCore/DeBruijn/Internal.hs

@@ -57,6 +57,7 @@ import Control.Monad.Reader
 import Control.Monad.State
 
 import Data.Bimap qualified as BM
+import Data.Hashable
 import Data.Map qualified as M
 import Data.Text qualified as T
 import Data.Word
@@ -102,7 +103,7 @@ the Num and write `DeBruijn (Index -1)`. This can be revisited when we implement
 -}
 newtype Index = Index Word64
   deriving stock (Generic)
-  deriving newtype (Show, Num, Enum, Real, Integral, Eq, Ord, Pretty, NFData, Read)
+  deriving newtype (Show, Num, Enum, Real, Integral, Eq, Ord, Hashable, Pretty, NFData, Read)
 
 -- | The LamAbs index (for debruijn indices) and the starting level of DeBruijn monad
 deBruijnInitIndex :: Index
@@ -113,7 +114,7 @@ deBruijnInitIndex = 0
 -- | A term name as a de Bruijn index.
 data NamedDeBruijn = NamedDeBruijn {ndbnString :: !T.Text, ndbnIndex :: !Index}
   deriving stock (Show, Generic, Read)
-  deriving anyclass (NFData)
+  deriving anyclass (Hashable, NFData)
 
 {-| A wrapper around `NamedDeBruijn` that *must* hold the invariant of name=`fakeName`.
 
@@ -123,7 +124,7 @@ but injection `ND->FND` is unsafe, thus they are not isomorphic.
 See NOTE: [Why newtype FakeNamedDeBruijn]
 -}
 newtype FakeNamedDeBruijn = FakeNamedDeBruijn { unFakeNamedDeBruijn :: NamedDeBruijn }
-  deriving newtype (Show, Eq, NFData, PrettyBy config)
+  deriving newtype (Show, Eq, Hashable, NFData, PrettyBy config)
 
 toFake :: DeBruijn -> FakeNamedDeBruijn
 toFake (DeBruijn ix) = FakeNamedDeBruijn $ NamedDeBruijn fakeName ix
@@ -142,7 +143,7 @@ instance Eq NamedDeBruijn where
 -- | A term name as a de Bruijn index, without the name string.
 newtype DeBruijn = DeBruijn {dbnIndex :: Index}
   deriving stock (Show, Generic, Eq)
-  deriving newtype (NFData)
+  deriving newtype (Hashable, NFData)
 
 -- | A type name as a de Bruijn index.
 newtype NamedTyDeBruijn = NamedTyDeBruijn NamedDeBruijn

plutus-core/plutus-core/src/Universe/Core.hs

@@ -60,6 +60,7 @@ import Data.Dependent.Sum
 import Data.GADT.Compare
 import Data.GADT.DeepSeq
 import Data.GADT.Show
+import Data.Hashable
 import Data.Kind
 import Data.Proxy
 import Data.Some.Newtype
@@ -793,3 +794,15 @@ instance Closed uni => NFData (SomeTypeIn uni) where
 
 instance (Closed uni, uni `Everywhere` NFData) => NFData (ValueOf uni a) where
     rnf = grnf
+
+instance (Closed uni, GEq uni) => Hashable (SomeTypeIn uni) where
+    hashWithSalt salt (SomeTypeIn uni) = hashWithSalt salt $ encodeUni uni
+
+instance (Closed uni, GEq uni, uni `Everywhere` Eq, uni `Everywhere` Hashable) =>
+        Hashable (ValueOf uni a) where
+    hashWithSalt salt (ValueOf uni x) =
+        bring (Proxy @Hashable) uni $ hashWithSalt salt (SomeTypeIn uni, x)
+
+instance (Closed uni, GEq uni, uni `Everywhere` Eq, uni `Everywhere` Hashable) =>
+        Hashable (Some (ValueOf uni)) where
+    hashWithSalt salt (Some s) = hashWithSalt salt s

plutus-core/untyped-plutus-core/src/UntypedPlutusCore/Core/Instance/Eq.hs

@@ -1,6 +1,7 @@
 -- editorconfig-checker-disable-file
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 
+{-# LANGUAGE ConstraintKinds      #-}
 {-# LANGUAGE FlexibleInstances    #-}
 {-# LANGUAGE TypeOperators        #-}
 {-# LANGUAGE UndecidableInstances #-}
@@ -19,11 +20,23 @@ import PlutusCore.Rename.Monad
 import Universe
 
 import Data.Foldable (for_)
+import Data.Hashable
 
 instance (GEq uni, Closed uni, uni `Everywhere` Eq, Eq fun, Eq ann) =>
             Eq (Term Name uni fun ann) where
     term1 == term2 = runEqRename $ eqTermM term1 term2
 
+type HashableTermConstraints uni fun ann =
+  ( GEq uni
+  , Closed uni
+  , uni `Everywhere` Eq
+  , uni `Everywhere` Hashable
+  , Hashable ann
+  , Hashable fun
+  )
+
+instance HashableTermConstraints uni fun ann => Hashable (Term Name uni fun ann)
+
 -- Simple Structural Equality of a `Term NamedDeBruijn`. This implies three things:
 -- a) We ignore the name part of the nameddebruijn
 -- b) We do not do equality "modulo init index, see deBruijnInitIndex". E.g. `LamAbs 0 (Var 0) /= LamAbs 1 (Var 1)`.
@@ -33,14 +46,20 @@ deriving stock instance
    (GEq uni, Closed uni, uni `Everywhere` Eq, Eq fun, Eq ann) =>
    Eq (Term NamedDeBruijn uni fun ann)
 
+instance HashableTermConstraints uni fun ann => Hashable (Term NamedDeBruijn uni fun ann)
+
 deriving stock instance
    (GEq uni, Closed uni, uni `Everywhere` Eq, Eq fun, Eq ann) =>
    Eq (Term FakeNamedDeBruijn uni fun ann)
 
+instance HashableTermConstraints uni fun ann => Hashable (Term FakeNamedDeBruijn uni fun ann)
+
 deriving stock instance
    (GEq uni, Closed uni, uni `Everywhere` Eq, Eq fun, Eq ann) =>
    Eq (Term DeBruijn uni fun ann)
 
+instance HashableTermConstraints uni fun ann => Hashable (Term DeBruijn uni fun ann)
+
 deriving stock instance (GEq uni, Closed uni, uni `Everywhere` Eq, Eq fun, Eq ann,
                   Eq (Term name uni fun ann)
                   ) =>  Eq (Program name uni fun ann)