control-monad-exception-0.4.3: control-monad-exception.cabal

name: control-monad-exception
version: 0.4.3
Cabal-Version:  >= 1.2.3
build-type: Simple
license: PublicDomain
author: Pepe Iborra
maintainer: pepeiborra@gmail.com
homepage: http://safe-tools.dsic.upv.es/mediawiki/index.php/Jose_Iborra/Papers/Exceptions
description: 
  This package provides explicitly typed, checked exceptions as a library.

  /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
  .
  New in version 0.4:
  .
    * Support for unchecked exceptions (with 'UncaughtException')
  .
    * Support for exception stack traces (with 'WithSrcLoc'). /Example/
  .
  >       f () = $withLocTH $ throw MyException
  >       g a  = $withLocTH $ f a
  >
  >       main = runEMT $ $withLocTH $ do
  >       g () `catchWithSrcLoc` \loc MyException ->
  >              lift $ putStrLn (showExceptionWithTrace loc MyException)
  .
  > -- Running @main@ produces the output:
  .
  >       *Main> main
  >       MyException
  >        in Main(example.hs): (12,6)
  >           Main(example.hs): (11,7)
  .

synopsis: Explicitly typed, checked exceptions with stack traces
category: Control, Monads
stability: experimental
tested-with: GHC ==6.8.2
tested-with: GHC ==6.10.2
tested-with: GHC ==6.10.3

Flag transformers
  description: Use transformers and monads-fd instead of mtl
  default: True 

Flag extensibleExceptions
  description: Use extensible-exception package
  default: False

Library
  buildable: True
  if flag(extensibleExceptions)
    build-depends:
      extensible-exceptions >= 0.1 && <0.2,
      base >= 3.0 && <4
  else
    build-depends:
      base >= 4 && < 5

  if flag(transformers)
    cpp-options: -DTRANSFORMERS
    build-depends:
      transformers >= 0.0.1 && <0.2,
      monads-fd >= 0.0 && <0.1
  else
    build-depends: mtl

  extensions:  MultiParamTypeClasses, 
               FunctionalDependencies,
               FlexibleInstances,
               EmptyDataDecls,
               DeriveDataTypeable,
               UndecidableInstances
  build-depends: pretty, template-haskell
  exposed-modules:
     Control.Monad.Exception.Class
     Control.Monad.Exception
  ghc-options: -Wall -fno-warn-name-shadowing