control-monad-exception: Explicitly typed, checked exceptions with stack traces

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This package provides explicitly typed, checked exceptions as a library.

Computations throwing different types of exception can be combined seamlessly.

Example

data Expr = Add Expr Expr | Div Expr Expr | Val Double
eval (Val x)     = return x
eval (Add a1 a2) = do
   v1 <- eval a1
   v2 <- eval a2
   let sum = v1 + v2
   if sum < v1 || sum < v2 then throw SumOverflow else return sum
eval (Div a1 a2) = do
   v1 <- eval a1
   v2 <- eval a2
   if v2 == 0 then throw DivideByZero else return (v1 / v2)
data DivideByZero = DivideByZero deriving (Show, Typeable)
data SumOverflow  = SumOverflow  deriving (Show, Typeable)
instance Exception DivideByZero
instance Exception SumOverflow

GHCi infers the following types

eval :: (Throws DivideByZero l, Throws SumOverflow l) => Expr -> EM l Double
eval `catch` \ (e::DivideByZero) -> return (-1)  :: Throws SumOverflow l => Expr -> EM l Double
runEM(eval `catch` \ (e::SomeException) -> return (-1))  :: Expr -> Double

In addition to explicitly typed exceptions this package provides:

f () = do throw MyException
g a  = do f a

main = runEMT $ do g () `catchWithSrcLoc`
                       \loc (e::MyException) -> lift(putStrLn$ showExceptionWithTrace loc e)

-- Running main produces the output:

*Main> main
 MyException
   in f, Main(example.hs): (1,6)
      g, Main(example.hs): (2,6)
      main, Main(example.hs): (5,9)
      main, Main(example.hs): (4,16)

Properties

Versions 0.1, 0.1.1, 0.1.2, 0.2, 0.3, 0.3.1, 0.3.2, 0.4, 0.4.1, 0.4.2, 0.4.3, 0.4.4, 0.4.5, 0.4.6, 0.4.7, 0.4.8, 0.5, 0.6, 0.8.0, 0.8.0.1, 0.8.0.2, 0.8.0.3, 0.8.0.4, 0.9.0, 0.9.1, 0.10.0, 0.10.1, 0.10.2, 0.10.3, 0.10.3.1, 0.11.1, 0.11.2, 0.11.3, 0.11.3, 0.11.4
Change log changelog
Dependencies base (>=3.0 && <5), extensible-exceptions (==0.1.*), failure (>=0.1 && <0.3), lifted-base (>=0.2.1), monad-control (>=0.3), monadloc (>=0.7), transformers (>=0.2), transformers-base (>=0.4.1) [details]
License LicenseRef-PublicDomain
Author Pepe Iborra
Maintainer pepeiborra@gmail.com
Category Control, Monads, Failure
Home page http://pepeiborra.github.com/control-monad-exception
Bug tracker http://github.com/pepeiborra/control-monad-exception/issues
Source repo head: git clone git://github.com/pepeiborra/control-monad-exception.git
Uploaded by PepeIborra at 2020-07-06T06:49:37Z

Modules

Flags

NameDescriptionDefaultType
extensibleexceptions

Use extensible-exception package

DisabledAutomatic

Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info

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