Safe Haskell	None
Language	Haskell2010

Bluefin.Exception

Contents

Synopsis

data Exception e (ex :: Effects)
try :: forall e (es :: Effects) a. (forall (ex :: Effects). Exception e ex -> Eff (ex :& es) a) -> Eff es (Either e a)
handle :: forall e (es :: Effects) a. (e -> Eff es a) -> (forall (ex :: Effects). Exception e ex -> Eff (ex :& es) a) -> Eff es a
catch :: forall e (es :: Effects) a. (forall (ex :: Effects). Exception e ex -> Eff (ex :& es) a) -> (e -> Eff es a) -> Eff es a
throw :: forall (ex :: Effects) (es :: Effects) e a. ex :> es => Exception e ex -> e -> Eff es a

Handle

Handle to an exception of type e

Instances details

e :> es => MonadFail (EffReader (Exception String e) es)
Instance details Defined in Bluefin.Internal Methods fail :: String -> EffReader (Exception String e) es a #

Handlers

Arguments

:: forall e (es :: Effects) a. (forall (ex :: Effects). Exception e ex -> Eff (ex :& es) a)
-> Eff es (Either e a)	`Left` if the exception was thrown, `Right` otherwise

>>> runPureEff $ try $ \e -> do
      throw e 42
      pure "No exception thrown"
Left 42

Arguments

:: forall e (es :: Effects) a. (e -> Eff es a)	If the exception is thrown, apply this handler
-> (forall (ex :: Effects). Exception e ex -> Eff (ex :& es) a)
-> Eff es a

handle, but with the argument order swapped

>>> runPureEff $ handle (pure . show) $ \e -> do
      throw e 42
      pure "No exception thrown"
"42"

Arguments

:: forall e (es :: Effects) a. (forall (ex :: Effects). Exception e ex -> Eff (ex :& es) a)
-> (e -> Eff es a)	If the exception is thrown, apply this handler
-> Eff es a

Arguments

:: forall (ex :: Effects) (es :: Effects) e a. ex :> es
=> Exception e ex
-> e	Value to throw
-> Eff es a

>>> runPureEff $ try $ \e -> do
      throw e 42
      pure "No exception thrown"
Left 42

>>> runPureEff $ try $ \e -> do
      pure "No exception thrown"
Right "No exception thrown"