Safe Haskell	Safe-Inferred
Language	Haskell2010

GHC.Utils.Panic.Plain

Description

Defines a simple exception type and utilities to throw it. The PlainGhcException type is a subset of the GhcException type. It omits the exception constructors that involve pretty-printing via SDoc.

There are two reasons for this:

To avoid import cycles / use of boot files. GHC.Utils.Outputable has many transitive dependencies. To throw exceptions from these modules, the functions here can be used without introducing import cycles.
To reduce the number of modules that need to be compiled to object code when loading GHC into GHCi. See #13101

Synopsis

data PlainGhcException
- = PlainSignal Int
- | PlainUsageError String
- | PlainCmdLineError String
- | PlainPanic String
- | PlainSorry String
- | PlainInstallationError String
- | PlainProgramError String
showPlainGhcException :: PlainGhcException -> ShowS
panic :: String -> a
sorry :: String -> a
pgmError :: String -> a
cmdLineError :: String -> a
cmdLineErrorIO :: String -> IO a
assertPanic :: String -> Int -> a
assert :: HasCallStack => Bool -> a -> a
assertM :: (HasCallStack, Monad m) => m Bool -> m ()
massert :: (HasCallStack, Applicative m) => Bool -> m ()

Documentation

data PlainGhcException Source #

This type is very similar to GhcException, but it omits the constructors that involve pretty-printing via SDoc. Due to the implementation of fromException for GhcException, this type can be caught as a GhcException.

Note that this should only be used for throwing exceptions, not for catching, as GhcException will not be converted to this type when catching.

Constructors

PlainSignal Int	Some other fatal signal (SIGHUP,SIGTERM)
PlainUsageError String	Prints the short usage msg after the error
PlainCmdLineError String	A problem with the command line arguments, but don't print usage.
PlainPanic String	The `impossible` happened.
PlainSorry String	The user tickled something that's known not to work yet, but we're not counting it as a bug.
PlainInstallationError String	An installation problem.
PlainProgramError String	An error in the user's code, probably.

Instances

Instances details

Exception PlainGhcException Source #
Instance details Defined in GHC.Utils.Panic.Plain Methods toException :: PlainGhcException -> SomeException Source # fromException :: SomeException -> Maybe PlainGhcException Source # displayException :: PlainGhcException -> String Source #
Show PlainGhcException Source #
Instance details Defined in GHC.Utils.Panic.Plain Methods showsPrec :: Int -> PlainGhcException -> ShowS Source # show :: PlainGhcException -> String Source # showList :: [PlainGhcException] -> ShowS Source #

showPlainGhcException :: PlainGhcException -> ShowS Source #

Append a description of the given exception to this string.

panic :: String -> a Source #

Panics and asserts.

sorry :: String -> a Source #

Panics and asserts.

pgmError :: String -> a Source #

Panics and asserts.

cmdLineError :: String -> a Source #

cmdLineErrorIO :: String -> IO a Source #

assertPanic :: String -> Int -> a Source #

Throw a failed assertion exception for a given filename and line number.

assert :: HasCallStack => Bool -> a -> a Source #

assertM :: (HasCallStack, Monad m) => m Bool -> m () Source #

massert :: (HasCallStack, Applicative m) => Bool -> m () Source #