summaryrefslogtreecommitdiff
path: root/config-freebsd.hs
diff options
context:
space:
mode:
authorJoey Hess2016-03-17 11:26:35 -0400
committerJoey Hess2016-03-17 11:58:24 -0400
commit86f3373dc429bd16f0153787eaa45049e44c6bb0 (patch)
tree27abb1e615d2df49e68576f661b0d3acc9b74bb8 /config-freebsd.hs
parent70b77dd31c4538361a844ef049bed9ad2f273a3b (diff)
let's not try to get outertarget from monad
To get outertarget from the Propellor monad, the monad would have to be parameteriszed with an outertarget type, since there's no single type. For example: newtype Propellor target p = Propellor { runWithHost :: RWST target () () IO p } deriving (Monad, Applicative, Functor) But then mkProperty becomes a problem, since the Propellor action passed to it needs to already be of UnixLike type: mkProperty :: Propellor UnixLike () -> Property UnixLike mkProperty a = Property unixLike a Could maybe live with that, but then `target` type check fails: Expected type: Propellor (Targeting combinedtarget) () Actual type: Propellor (Targeting oldtarget) () Problem being that it's reusing the `a` which is a Propellor target () target newtarget (Property oldtarget a) = Property (intersectTarget oldtarget newtarget) a And, the new Property has a different target, so it can't use the old `a`. So, I'd need a way to cast one Propellor target () to a different target. Maybe: target newtarget (Property oldtarget (Propellor a)) = let combinedtarget = intersectTarget oldtarget newtarget in Property combinedtarget (Propellor (unsafeCoerce a)) But is that safe?? Even if it is, I can't see how to make ensureProperty get the outertarget type. It returns Propellor (Targeting outertarget) (), which can read the target from the RWST monad, but how to use that where the type of the function is defined? Rather than all that complication, it doesn't seem too bad to require outertarget be passed to ensureProperty.
Diffstat (limited to 'config-freebsd.hs')
0 files changed, 0 insertions, 0 deletions