diff options
| -rw-r--r-- | libraries/template-haskell/Language/Haskell/TH/Syntax.hs | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/libraries/template-haskell/Language/Haskell/TH/Syntax.hs b/libraries/template-haskell/Language/Haskell/TH/Syntax.hs index 20c239671e..00ac0b308b 100644 --- a/libraries/template-haskell/Language/Haskell/TH/Syntax.hs +++ b/libraries/template-haskell/Language/Haskell/TH/Syntax.hs @@ -112,9 +112,8 @@ class Monad m => Quasi m where ----------------------------------------------------- instance Quasi IO where - qNewName s = do { n <- readIORef counter - ; writeIORef counter (n+1) - ; return (mkNameU s n) } + qNewName s = do { n <- atomicModifyIORef' counter (\x -> (x + 1, x)) + ; pure (mkNameU s n) } qReport True msg = hPutStrLn stderr ("Template Haskell error: " ++ msg) qReport False msg = hPutStrLn stderr ("Template Haskell error: " ++ msg) |