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1. spawnSignalled :: Process a -> (a -> Process ()) -> Process ProcessId

   distributed-process-extras	Control.Distributed.Process.Extras.Internal.Primitives

   Spawn a new (local) process. This variant takes an initialisation action and a secondary expression from the result of the initialisation to Process (). The spawn operation synchronises on the completion of the before action, such that the calling process is guaranteed to only see the newly spawned ProcessId once the initialisation has successfully completed.

2. periodically :: TimeInterval -> Process () -> Process TimerRef

   distributed-process-extras	Control.Distributed.Process.Extras.Timer

   runs the supplied process action(s) repeatedly at intervals of t

3. localLend :: forall (lentEs :: [Effect]) (es :: [Effect]) (handlerEs :: [Effect]) (localEs :: [Effect]) a . (HasCallStack, KnownSubset lentEs es, SharedSuffix es handlerEs) => LocalEnv localEs handlerEs -> UnliftStrategy -> ((forall r . () => Eff (lentEs ++ localEs) r -> Eff localEs r) -> Eff es a) -> Eff es a

   effectful-core	Effectful.Dispatch.Dynamic

   Lend effects to the local environment with a given unlifting strategy. Generalizes localSeqLend.

4. localLift :: forall (es :: [Effect]) (handlerEs :: [Effect]) (localEs :: [Effect]) a . (HasCallStack, SharedSuffix es handlerEs) => LocalEnv localEs handlerEs -> UnliftStrategy -> ((forall r . () => Eff es r -> Eff localEs r) -> Eff es a) -> Eff es a

   effectful-core	Effectful.Dispatch.Dynamic

   Create a local lifting function with the given strategy.

5. localLiftUnlift :: forall (es :: [Effect]) (handlerEs :: [Effect]) (localEs :: [Effect]) a . (HasCallStack, SharedSuffix es handlerEs) => LocalEnv localEs handlerEs -> UnliftStrategy -> ((forall r . () => Eff es r -> Eff localEs r) -> (forall r . () => Eff localEs r -> Eff es r) -> Eff es a) -> Eff es a

   effectful-core	Effectful.Dispatch.Dynamic

   Create a local lifting and unlifting function with the given strategy. Useful for lifting complicated Eff computations where the monadic action shows in both positive (as a result) and negative (as an argument) position. Note: depending on the computation you're lifting localUnlift along with withLiftMap might be enough and is more efficient.

6. localLiftUnliftIO :: forall (es :: [Effect]) (handlerEs :: [Effect]) (localEs :: [Effect]) a . (HasCallStack, SharedSuffix es handlerEs, IOE :> es) => LocalEnv localEs handlerEs -> UnliftStrategy -> ((forall r . () => IO r -> Eff localEs r) -> (forall r . () => Eff localEs r -> IO r) -> IO a) -> Eff es a

   effectful-core	Effectful.Dispatch.Dynamic

   Create a local unlifting function with the given strategy along with an unrestricted lifting function. Useful for lifting complicated IO computations where the monadic action shows in both positive (as a result) and negative (as an argument) position. Note: depending on the computation you're lifting localUnliftIO along with withLiftMapIO might be enough and is more efficient.

7. reallyUnsafeLiftMapIO :: forall a b (es :: [Effect]) . (IO a -> IO b) -> Eff es a -> Eff es b

   effectful-core	Effectful.Dispatch.Static.Unsafe

   Utility for lifting IO computations of type

   IO a -> IO b
   

   to

   Eff es a -> Eff es b
   

   This function is really unsafe because:
   • It can be used to introduce arbitrary IO actions into pure Eff computations.
   • The IO computation must run its argument in a way that's perceived as sequential to the outside observer, e.g. in the same thread or in a worker thread that finishes before the argument is run again.
   Warning: if you disregard the second point, you will experience weird bugs, data races or internal consistency check failures. When in doubt, use unsafeLiftMapIO, especially since this version saves only a simple safety check per call of reallyUnsafeLiftMapIO f.

8. reallyUnsafeUnliftIO :: forall (es :: [Effect]) a . ((forall r . () => Eff es r -> IO r) -> IO a) -> Eff es a

   effectful-core	Effectful.Dispatch.Static.Unsafe

   Create an unlifting function. This function is really unsafe because:

   • It can be used to introduce arbitrary IO actions into pure Eff computations.
   • Unlifted Eff computations must be run in a way that's perceived as sequential to the outside observer, e.g. in the same thread as the caller of reallyUnsafeUnliftIO or in a worker thread that finishes before another unlifted computation is run.
   Warning: if you disregard the second point, you will experience weird bugs, data races or internal consistency check failures. When in doubt, use unsafeSeqUnliftIO, especially since this version saves only a simple safety check per call of the unlifting function.

9. data CallStack

   effectful-core	Effectful.Error.Dynamic

   CallStacks are a lightweight method of obtaining a partial call-stack at any point in the program. A function can request its call-site with the HasCallStack constraint. For example, we can define

   putStrLnWithCallStack :: HasCallStack => String -> IO ()
   

   as a variant of putStrLn that will get its call-site and print it, along with the string given as argument. We can access the call-stack inside putStrLnWithCallStack with callStack.

   >>> :{
   putStrLnWithCallStack :: HasCallStack => String -> IO ()
   putStrLnWithCallStack msg = do
   putStrLn msg
   putStrLn (prettyCallStack callStack)
   :}
   

   Thus, if we call putStrLnWithCallStack we will get a formatted call-stack alongside our string.

   >>> putStrLnWithCallStack "hello"
   hello
   CallStack (from HasCallStack):
   putStrLnWithCallStack, called at <interactive>:... in interactive:Ghci...
   

   GHC solves HasCallStack constraints in three steps:
   1. If there is a CallStack in scope -- i.e. the enclosing function has a HasCallStack constraint -- GHC will append the new call-site to the existing CallStack.
   2. If there is no CallStack in scope -- e.g. in the GHCi session above -- and the enclosing definition does not have an explicit type signature, GHC will infer a HasCallStack constraint for the enclosing definition (subject to the monomorphism restriction).
   3. If there is no CallStack in scope and the enclosing definition has an explicit type signature, GHC will solve the HasCallStack constraint for the singleton CallStack containing just the current call-site.
   CallStacks do not interact with the RTS and do not require compilation with -prof. On the other hand, as they are built up explicitly via the HasCallStack constraints, they will generally not contain as much information as the simulated call-stacks maintained by the RTS. A CallStack is a [(String, SrcLoc)]. The String is the name of function that was called, the SrcLoc is the call-site. The list is ordered with the most recently called function at the head. NOTE: The intrepid user may notice that HasCallStack is just an alias for an implicit parameter ?callStack :: CallStack. This is an implementation detail and should not be considered part of the CallStack API, we may decide to change the implementation in the future.

10. getCallStack :: CallStack -> [([Char], SrcLoc)]

    effectful-core	Effectful.Error.Dynamic

    Extract a list of call-sites from the CallStack. The list is ordered by most recent call.

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