Tracing

src/AFRP.hs

@@ -8,9 +8,9 @@ module AFRP
   , events
   , switch
   , preMapAccum
-  , preMapAccumUTCTime
+  , preMapAccumRequest
   , mapAccum
-  , mapAccumUTCTime
+  , mapAccumRequest
   , changes
   , whenA
   , filterA
@@ -18,6 +18,7 @@ module AFRP
   , (>>|)
   , toEvent
   , lMerge
+  , Request(..)
   ) where
 
 import Control.Category (Category(..), (>>>))
@@ -27,9 +28,16 @@ import Data.Time (UTCTime)
 import Control.Monad.Fix (MonadFix (mfix))
 import Data.Either (fromLeft)
 import Data.Bool (bool)
+import Data.UUID (UUID)
+
+data Request = Request
+  { requestTime :: !UTCTime
+  , requestTraceId :: !UUID
+  }
+  deriving Show
 
 newtype Mealy eff a b = Mealy
-  { runMealy :: forall m. MonadFix m => (forall x. eff x -> m x) -> UTCTime -> a -> m (b, Mealy eff a b) }
+  { runMealy :: forall m. MonadFix m => (forall x. eff x -> m x) -> Request -> a -> m (b, Mealy eff a b) }
 
 eff :: (a -> eff b) -> Mealy eff a b
 eff f = Mealy $ \nt _ x ->
@@ -101,8 +109,8 @@ preMapAccum f x extract = go x
       let next = f b a
       in pure (extract b, go next)
 
-preMapAccumUTCTime :: (UTCTime -> x -> a -> x) -> x -> (x -> b) -> Mealy eff a b
-preMapAccumUTCTime f x extract = go x
+preMapAccumRequest :: (Request -> x -> a -> x) -> x -> (x -> b) -> Mealy eff a b
+preMapAccumRequest f x extract = go x
   where
     go b = Mealy $ \_ t a ->
       let next = f t b a
@@ -115,8 +123,8 @@ mapAccum f x extract = go x
       let next = f b a
       in pure (extract next, go next)
 
-mapAccumUTCTime :: (UTCTime -> x -> a -> x) -> x -> (x -> b) -> Mealy eff a b
-mapAccumUTCTime f x extract = go x
+mapAccumRequest :: (Request -> x -> a -> x) -> x -> (x -> b) -> Mealy eff a b
+mapAccumRequest f x extract = go x
   where
     go b = Mealy $ \_ t a ->
       let next = f t b a