lens-4.7.0.1: Lenses, Folds and Traversals

Copyright(C) 2013-14 Edward Kmett
LicenseBSD-style (see the file LICENSE)
MaintainerEdward Kmett <ekmett@gmail.com>
Stabilityprovisional
PortabilityControl.Exception
Safe HaskellSafe-Inferred
LanguageHaskell98

System.Exit.Lens

Description

These prisms can be used with the combinators in Control.Exception.Lens.

Synopsis

Documentation

class AsExitCode p f t where

Exit codes that a program can return with:

Minimal complete definition

Nothing

_ExitFailure :: (AsExitCode p f t, Choice p, Applicative f) => Optic' p f t Int

indicates program failure with an exit code. The exact interpretation of the code is operating-system dependent. In particular, some values may be prohibited (e.g. 0 on a POSIX-compliant system).

_ExitFailure :: Prism' ExitCode      Int
_ExitFailure :: Prism' SomeException Int

_ExitSuccess :: (AsExitCode p f t, Choice p, Applicative f) => Optic' p f t ()

indicates successful termination;

_ExitSuccess :: Prism' ExitCode      ()
_ExitSuccess :: Prism' SomeException ()