Support text-2.0

hashable.cabal

@@ -87,7 +87,7 @@ library
     , containers  >=0.4.2.1 && <0.7
     , deepseq     >=1.3     && <1.5
     , ghc-prim
-    , text        >=0.12    && <1.3
+    , text        >=0.12    && <2.1
 
   if !impl(ghc >=9.2)
     build-depends: base-orphans >=0.8.6

src/Data/Hashable/Class.hs

@@ -722,6 +722,22 @@ instance Hashable BSI.ShortByteString where
         hashByteArrayWithSalt ba 0 (BSI.length sbs) (hashWithSalt salt (BSI.length sbs))
 #endif
 
+#if MIN_VERSION_text(2,0,0)
+
+instance Hashable T.Text where
+    hashWithSalt salt (T.Text (TA.ByteArray arr) off len) =
+        hashByteArrayWithSalt arr off len (hashWithSalt salt len)
+
+instance Hashable TL.Text where
+    hashWithSalt salt = finalise . TL.foldlChunks step (SP salt 0)
+      where
+        finalise (SP s l) = hashWithSalt s l
+        step (SP s l) (T.Text (TA.ByteArray arr) off len) = SP
+            (hashByteArrayWithSalt arr off len s)
+            (l + len)
+
+#else
+
 instance Hashable T.Text where
     hashWithSalt salt (T.Text arr off len) =
         hashByteArrayWithSalt (TA.aBA arr) (off `shiftL` 1) (len `shiftL` 1)
@@ -735,6 +751,8 @@ instance Hashable TL.Text where
             (hashByteArrayWithSalt (TA.aBA arr) (off `shiftL` 1) (len `shiftL` 1) s)
             (l + len)
 
+#endif
+
 -- | Compute the hash of a ThreadId.
 hashThreadId :: ThreadId -> Int
 hashThreadId (ThreadId t) = hash (fromIntegral (getThreadId t) :: Int)

tests/Regress.hs

@@ -48,7 +48,12 @@ regressions = [] ++
         hs @=? nub hs
 #if WORD_SIZE_IN_BITS == 64
     , testCase "64 bit Text" $ do
-        hash ("hello world" :: Text) @=? -3875242662334356092
+        hash ("hello world" :: Text) @=?
+#if MIN_VERSION_text(2,0,0)
+            4078614214911247440
+#else
+            -3875242662334356092
+#endif
 #endif
     , F.testGroup "concatenation"
         [ testCase "String" $ do