add <*> to Applicative for Transaction

2021-09-07 13:31:28 +02:00
parent 31396e46e3
commit 8936e6211e
1 changed files with 4 additions and 0 deletions
--- a/src/runtime/haskell/PGF2/Transactions.hsc
+++ b/src/runtime/haskell/PGF2/Transactions.hsc
@@ -24,6 +24,10 @@ instance Functor Transaction where

 instance Applicative Transaction where
  pure x = Transaction $ \c_db c_revision c_exn -> return x
+  f <*> g = do
+    f <- f
+    g <- g
+    return (f g)

 instance Monad Transaction where
  (Transaction f) >>= g = Transaction $ \c_db c_revision c_exn -> do