Safe Haskell	None
Language	Haskell2010

Mikan.Utils.Impossible

Contents

Description

An interface for reporting "impossible" errors.

Synopsis

Documentation

"Impossible" errors, annotated with a file name and a line number corresponding to the source code location of the error.

Constructors

Impossible CallStack	We reached a program point which should be unreachable.
Unreachable CallStack	`Impossible` with a different error message. Used when we reach a program point which can in principle be reached, but not for a certain run.
ImpMissingDefinitions [ShortText] ShortText	We reached a program point without all the required primitives or BUILTIN to proceed forward. `ImpMissingDefinitions neededDefs forThis`

Instances details

EmbPrj Impossible Source #
Instance details Defined in Mikan.TypeChecking.Serialise.Instances.Common Methods icode :: Impossible -> S Word32 Source # icod_ :: Impossible -> S Word32 Source # value :: Word32 -> R Impossible Source #
NFData Impossible Source #
Instance details Defined in Mikan.Utils.Impossible Methods rnf :: Impossible -> () #
Exception Impossible Source #
Instance details Defined in Mikan.Utils.Impossible Methods toException :: Impossible -> SomeException # fromException :: SomeException -> Maybe Impossible # displayException :: Impossible -> String # backtraceDesired :: Impossible -> Bool #
Show Impossible Source #
Instance details Defined in Mikan.Utils.Impossible Methods showsPrec :: Int -> Impossible -> ShowS # show :: Impossible -> String # showList :: [Impossible] -> ShowS #
Eq Impossible Source #
Instance details Defined in Mikan.Utils.Impossible Methods (==) :: Impossible -> Impossible -> Bool # (/=) :: Impossible -> Impossible -> Bool #
Ord Impossible Source #
Instance details Defined in Mikan.Utils.Impossible Methods compare :: Impossible -> Impossible -> Ordering # (<) :: Impossible -> Impossible -> Bool # (<=) :: Impossible -> Impossible -> Bool # (>) :: Impossible -> Impossible -> Bool # (>=) :: Impossible -> Impossible -> Bool # max :: Impossible -> Impossible -> Impossible # min :: Impossible -> Impossible -> Impossible #

Throwing impossible errors

Construct a value of Impossible reporting the location where you call this function.

Throw an Impossible error reporting the location where you place __IMPOSSIBLE__.

Throw an Impossible error reporting the caller's call site.

Throw an Unreachable error reporting the caller's call site.

Abort by throwing an "impossible" error. You should not use this function directly; use __IMPOSSIBLE__ instead.

Monads in which we can catch an "impossible" error, if possible.

Minimal complete definition

Methods

Catch any Impossible exception.

catchImpossibleJust :: (Impossible -> Maybe b) -> m a -> (b -> m a) -> m a Source #

Catch only Impossible exceptions selected by the filter.

Version of catchImpossible with argument order suiting short handlers.

Version of catchImpossibleJust with argument order suiting short handlers.

Instances details

CatchImpossible TCM Source #	Like `catchError`, but resets the state completely before running the handler. This means it also loses changes to the `stPersistentState`. The intended use is to catch internal errors during debug printing. In debug printing, we are not expecting state changes.
Instance details Defined in Mikan.TypeChecking.Monad.Base Methods catchImpossible :: TCM a -> (Impossible -> TCM a) -> TCM a Source # catchImpossibleJust :: (Impossible -> Maybe b) -> TCM a -> (b -> TCM a) -> TCM a Source # handleImpossible :: (Impossible -> TCM a) -> TCM a -> TCM a Source # handleImpossibleJust :: (Impossible -> Maybe b) -> (b -> TCM a) -> TCM a -> TCM a Source #
CatchImpossible IO Source #
Instance details Defined in Mikan.Utils.Impossible Methods catchImpossible :: IO a -> (Impossible -> IO a) -> IO a Source # catchImpossibleJust :: (Impossible -> Maybe b) -> IO a -> (b -> IO a) -> IO a Source # handleImpossible :: (Impossible -> IO a) -> IO a -> IO a Source # handleImpossibleJust :: (Impossible -> Maybe b) -> (b -> IO a) -> IO a -> IO a Source #