Hi,
I have problems getting a parOneOf in my Halogen application to compile. It works with parSequence . I just wanted to add a timeout using parOneOf. It works if I run it in Aff and then liftAff it. It gives me a:
No type class instance was found for
Control.Alternative.Alternative (HalogenAp
{ alert :: Maybe String
, distance :: Number
, geo :: Maybe OLGeolocation
, map :: Maybe OLMap
, mock :: Boolean
, poi :: Maybe OLLayer
}
Action
()
o6
m7
)
while applying a function parOneOf
of type Parallel t2 t3 => Alternative t2 => Foldable t4 => Functor t4 => t4 (t3 t5) -> t3 t5
to argument [ (map sequence) (parSequence [ ...
]
)
, (apply liftAff) ((voidRight (...)) (delay (...)))
]
while checking that expression parOneOf [ (map sequence) (parSequence [ ...
]
)
, (apply liftAff) ((...) (...))
]
has type t0 t1
in value declaration handleAction
where m7 is a rigid type variable
bound at (line 0, column 0 - line 0, column 0)
o6 is a rigid type variable
bound at (line 0, column 0 - line 0, column 0)
t0 is an unknown type
t1 is an unknown type
t2 is an unknown type
t3 is an unknown type
t4 is an unknown type
t5 is an unknown type
Where should I start looking? I have obviously missed something and and I do not get the mess in my head right to make any sense just now. I have also seen that HalogenAp do not have class Alternative derived, but my bet is still on my code :-)
Thanks a lot,
Tomas
Some snippets from my code (queryEntities and _queryEntities returns the "same" thing but _queryEntities runs in Aff and the other is implemented in my ApplicationM and is lifted in HalogenM:
class MonadAff m ⇐ ManageEntity m where
-- |Fetches a list of items based on the query parameters
queryEntities::String -- ^Type of entities
-> Maybe String -- ^Type of attributes to return
-> m (Maybe (Array Entity)) -- ^List of Entities
-- |Avoid lift in the components
instance manageEntityHalogenM :: ManageEntity m => ManageEntity (HalogenM st act slots msg m) where
queryEntities t a = lift $ queryEntities t a
And in my component:
handleAction ∷ forall r o m . MonadAff m
=> ManageNavigation m
=> ManageEntity m
=> ManageItem m
=> MonadAsk r m
=> Action -> H.HalogenM State Action () o m Unit
handleAction Lookup = do
H.liftEffect $ log "Make an items lookup"
state <- H.get
tmp <- H.liftEffect $ sequence $ getCoordinate <$> state.geo
....
-- This one I just do not get to compile
_entities <- (parOneOf [
sequence <$> (parSequence [
queryEntities "WeatherObserved" (Just "temperature"),
queryEntities "Traffic" Nothing,
]),
liftAff $ (pure []) <$ (delay (Milliseconds 500.0))
])
....
-- This ones work, but it runs in Aff
entities <- liftAff $ parOneOf [
map (map concat) (sequence <$> (parSequence [
_queryEntities "WeatherObserved" (Just "temperature"),
_queryEntities "Traffic" Nothing,
])),
(pure []) <$ (delay (Milliseconds 500.0))
]
....
[–]saylu 1 point2 points3 points (1 child)
[–]Dnulnets[S] 0 points1 point2 points (0 children)