Add full validation of Sapling address to parser

src/ZGoTx.hs

@@ -17,6 +17,7 @@ import GHC.Generics
 import Text.Megaparsec hiding (State)
 import Text.Megaparsec.Char
 import ZcashHaskell.Orchard
+import ZcashHaskell.Sapling (isValidShieldedAddress)
 
 -- | Type to model a ZGo transaction
 data ZGoTx = ZGoTx
@@ -133,9 +134,9 @@ pSaplingAddress :: Parser MemoToken
 pSaplingAddress = do
   string "zs"
   a <- some alphaNumChar
-  if length a /= 76
-    then fail "Failed to parse Sapling address"
-    else pure $ Address $ T.pack ("zs" <> a)
+  if isValidShieldedAddress (E.encodeUtf8 $ "zs" <> T.pack a)
+    then pure $ Address $ T.pack ("zs" <> a)
+    else fail "Failed to parse Sapling address"
 
 pUnifiedAddress :: Parser MemoToken
 pUnifiedAddress = do