From 25942fb0cca0ca90933026bf959506e099ff95a4 Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Thu, 10 Apr 2014 17:22:32 -0400 Subject: Propellor monad is a Reader for HostAttr So far, the hostname is only used to improve a message in withPrivData, but I anticipate using HostAttr for a lot more. --- Propellor/Exception.hs | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) create mode 100644 Propellor/Exception.hs (limited to 'Propellor/Exception.hs') diff --git a/Propellor/Exception.hs b/Propellor/Exception.hs new file mode 100644 index 00000000..bd9212a8 --- /dev/null +++ b/Propellor/Exception.hs @@ -0,0 +1,16 @@ +{-# LANGUAGE PackageImports #-} + +module Propellor.Exception where + +import qualified "MonadCatchIO-transformers" Control.Monad.CatchIO as M +import Control.Exception +import Control.Applicative + +import Propellor.Types + +-- | Catches IO exceptions and returns FailedChange. +catchPropellor :: Propellor Result -> Propellor Result +catchPropellor a = either (\_ -> FailedChange) id <$> tryPropellor a + +tryPropellor :: Propellor a -> Propellor (Either IOException a) +tryPropellor = M.try -- cgit v1.3-2-g0d8e