control-monad-exception: Explicitly typed, checked exceptions with stack traces
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
This package provides, among other things:
Support for explicitly documented, unchecked exceptions (with
tryEM
).Support for selective unchecked exceptions (with
UncaughtException
).Support for exception stack traces (experimental). Example:
f () = $withLocTH $ throw MyException g a = $withLocTH $ f a main = runEMT $ $withLocTH $ do g () `catchWithSrcLoc` \loc (e::MyException) -> lift(putStrLn$ showExceptionWithTrace loc e)
-- Running main produces the output:
*Main> main MyException in Main(example.hs): (12,6) Main(example.hs): (11,7)
Modules
[Index]
Flags
Automatic Flags
Name | Description | Default |
---|---|---|
transformers | Use transformers and monads-fd instead of mtl | Enabled |
extensibleexceptions | Use extensible-exception package | Disabled |
Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info
Downloads
- control-monad-exception-0.4.8.tar.gz [browse] (Cabal source package)
- Package description (as included in the package)
Maintainer's Corner
For package maintainers and hackage trustees
Candidates
Versions [RSS] | 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, 0.11.4 |
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Dependencies | base (>=3.0 && <5), extensible-exceptions (>=0.1 && <0.2), monads-fd (>=0.0 && <0.1), mtl, pretty, template-haskell, transformers (>=0.0.1 && <0.2) [details] |
License | LicenseRef-PublicDomain |
Author | Pepe Iborra |
Maintainer | pepeiborra@gmail.com |
Category | Control, Monads |
Home page | http://pepeiborra.github.com/control-monad-exception |
Uploaded | by PepeIborra at 2009-10-27T18:35:36Z |
Distributions | |
Reverse Dependencies | 8 direct, 1102 indirect [details] |
Downloads | 24982 total (126 in the last 30 days) |
Rating | (no votes yet) [estimated by Bayesian average] |
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Status | Docs uploaded by user Build status unknown [no reports yet] |