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-rw-r--r--src/Propellor/Property.hs11
-rw-r--r--src/Propellor/Types.hs10
2 files changed, 16 insertions, 5 deletions
diff --git a/src/Propellor/Property.hs b/src/Propellor/Property.hs
index 342db1a5..95805054 100644
--- a/src/Propellor/Property.hs
+++ b/src/Propellor/Property.hs
@@ -142,11 +142,12 @@ ensureProperty :: Property NoInfo -> Propellor Result
ensureProperty = catchPropellor . propertySatisfy
-- | Makes a Property only need to do anything when a test succeeds.
-check :: IO Bool -> Property i -> Property i
-check c p = adjustPropertySatisfy p $ \satisfy -> ifM (liftIO c)
- ( satisfy
- , return NoChange
- )
+check :: (LiftPropellor m) => m Bool -> Property i -> Property i
+check c p = adjustPropertySatisfy p $ \satisfy ->
+ ifM (liftPropellor c)
+ ( satisfy
+ , return NoChange
+ )
-- | Tries the first property, but if it fails to work, instead uses
-- the second.
diff --git a/src/Propellor/Types.hs b/src/Propellor/Types.hs
index fc700df0..5904374e 100644
--- a/src/Propellor/Types.hs
+++ b/src/Propellor/Types.hs
@@ -29,6 +29,7 @@ module Propellor.Types
, CombinedType
, combineWith
, Propellor(..)
+ , LiftPropellor(..)
, EndAction(..)
, module Propellor.Types.OS
, module Propellor.Types.Dns
@@ -72,6 +73,15 @@ newtype Propellor p = Propellor { runWithHost :: RWST Host [EndAction] () IO p }
, MonadMask
)
+class LiftPropellor m where
+ liftPropellor :: m a -> Propellor a
+
+instance LiftPropellor Propellor where
+ liftPropellor = id
+
+instance LiftPropellor IO where
+ liftPropellor = liftIO
+
instance Monoid (Propellor Result) where
mempty = return NoChange
-- | The second action is only run if the first action does not fail.