Compat with ghc 8.8

Author: pepeiborra

hls-plugin-api/src/Ide/Plugin/Config.hs

@@ -25,6 +25,7 @@ import qualified Data.Aeson.Types    as A
 import           Data.Default
 import           Data.HashMap.Strict (HashMap)
 import qualified Data.HashMap.Strict as HM
+import           Data.Maybe          (fromMaybe)
 import qualified Data.Text           as T
 import           GHC.Exts            (toList)
 import           GHC.Generics        (Generic)
@@ -95,7 +96,7 @@ parsePlugins :: HashMap T.Text PluginConfig -> Value -> A.Parser (HashMap T.Text
 parsePlugins defValue = A.withObject "Config.plugins" $ \o -> do
   let -- parseOne :: Key -> Value -> A.Parser (T.Text, PluginConfig)
       parseOne (preview _String . toJSON -> Just pId) pConfig = do
-        let defPluginConfig = HM.findWithDefault def pId defValue
+        let defPluginConfig = fromMaybe def $ HM.lookup pId defValue
         pConfig' <- parsePluginConfig defPluginConfig pConfig
         return (pId, pConfig')
       parseOne _ _ = fail "Expected plugin id to be a string"