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The latest version of control-monad-exception is 0.11.4-0.

control-monad-exception

Version 0.1 revision 0 uploaded by PepeIborra.

Package meta

Synopsis
Explicitly typed exceptions
Description

This package provides explicitly typed 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
Author
Pepe Iborra
Bug reports
n/a
Category
Control, Monads
Copyright
n/a
Homepage
http://github.com/pepeiborra/control-monad-exception
Maintainer
pepeiborra@gmail.com
Package URL
n/a
Stability
experimental

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