Silence error when calling discoverySearch without the service

1 files changed, 12 insertions, 2 deletions

diff --git a/src/Erebos/Error.hs b/src/Erebos/Error.hs
index 3bb8736..da9db75 100644
--- a/src/Erebos/Error.hs
+++ b/src/Erebos/Error.hs
@@ -3,19 +3,24 @@ module Erebos.Error (
     showErebosError,
 
     FromErebosError(..),
+    throwErebosError,
     throwOtherError,
 ) where
 
 import Control.Monad.Except
 
+import {-# SOURCE #-} Erebos.Network.Protocol
+
 
 data ErebosError
     = ManyErrors [ ErebosError ]
     | OtherError String
+    | UnhandledService ServiceID
 
 showErebosError :: ErebosError -> String
 showErebosError (ManyErrors errs) = unlines $ map showErebosError errs
 showErebosError (OtherError str) = str
+showErebosError (UnhandledService svc) = "unhandled service ‘" ++ show svc ++ "’"
 
 instance Semigroup ErebosError where
     ManyErrors [] <> b = b
@@ -23,7 +28,7 @@ instance Semigroup ErebosError where
     ManyErrors a <> ManyErrors b = ManyErrors (a ++ b)
     ManyErrors a <> b = ManyErrors (a ++ [ b ])
     a <> ManyErrors b = ManyErrors (a : b)
-    a@OtherError {} <> b@OtherError {} = ManyErrors [ a, b ]
+    a <> b = ManyErrors [ a, b ]
 
 instance Monoid ErebosError where
     mempty = ManyErrors []
@@ -31,9 +36,14 @@ instance Monoid ErebosError where
 
 class FromErebosError e where
     fromErebosError :: ErebosError -> e
+    toErebosError :: e -> Maybe ErebosError
 
 instance FromErebosError ErebosError where
     fromErebosError = id
+    toErebosError = Just
+
+throwErebosError :: (MonadError e m, FromErebosError e) => ErebosError -> m a
+throwErebosError = throwError . fromErebosError
 
 throwOtherError :: (MonadError e m, FromErebosError e) => String -> m a
-throwOtherError = throwError . fromErebosError . OtherError
+throwOtherError = throwErebosError . OtherError