Copyright	© 2020-2021 IOHK
License	Apache-2.0
Safe Haskell	None
Language	Haskell2010

Cardano.Wallet.Util

Contents

Partial functions for "impossible" situations
- Handling errors for "impossible" situations.
String formatting
StateT
HTTP(S) URIs

Description

General utility functions.

Synopsis

type HasCallStack = ?callStack :: CallStack
internalError :: HasCallStack => Builder -> a
tina :: HasCallStack => Builder -> [ Maybe a] -> a
invariant :: HasCallStack => String -> a -> (a -> Bool ) -> a
isInternalError :: ErrorCall -> Maybe String
tryInternalError :: MonadUnliftIO m => a -> m ( Either String a)
newtype ShowFmt a = ShowFmt {
- unShowFmt :: a
}
mapFirst :: (a -> a) -> [a] -> [a]
modifyM :: forall m s. Monad m => (s -> m s) -> StateT s m ()
uriToText :: URI -> Text
parseURI :: Text -> Either TextDecodingError URI

Partial functions for "impossible" situations

type HasCallStack = ?callStack :: CallStack Source #

Request a CallStack.

NOTE: The implicit parameter ?callStack :: CallStack is an implementation detail and should not be considered part of the CallStack API, we may decide to change the implementation in the future.

Since: base-4.9.0.0

internalError :: HasCallStack => Builder -> a Source #

Calls the error function, which will usually crash the program.

tina :: HasCallStack => Builder -> [ Maybe a] -> a Source #

Take the first Just from a list of Maybe , or die trying. There is no alternative.

invariant Source #

Arguments

:: HasCallStack
=> String	The message
-> a	The value to test
-> (a -> Bool )	The predicate
-> a

Checks whether or not an invariant holds, by applying the given predicate to the given value.

If the invariant does not hold (indicated by the predicate function returning False ), throws an error with the specified message.

>>> invariant "not empty" [1,2,3] (not . null)
[1, 2, 3]

>>> invariant "not empty" [] (not . null)
*** Exception: not empty

Handling errors for "impossible" situations.

isInternalError :: ErrorCall -> Maybe String Source #

Tests whether an Exception was caused by internalError .

tryInternalError :: MonadUnliftIO m => a -> m ( Either String a) Source #

Evaluates a pure expression to WHNF and handles any occurrence of internalError .

This is intended for use in testing. Don't use this in application code -- that's what normal IO exceptions are for.

String formatting

newtype ShowFmt a Source #

A polymorphic wrapper type with a custom show instance to display data through Buildable instances.

Constructors

ShowFmt
Fields unShowFmt :: a

Instances

Instances details

Eq a => Eq ( ShowFmt a) Source #
Instance details Defined in Cardano.Wallet.Util Methods (==) :: ShowFmt a -> ShowFmt a -> Bool Source # (/=) :: ShowFmt a -> ShowFmt a -> Bool Source #
Ord a => Ord ( ShowFmt a) Source #
Instance details Defined in Cardano.Wallet.Util Methods compare :: ShowFmt a -> ShowFmt a -> Ordering Source # (<) :: ShowFmt a -> ShowFmt a -> Bool Source # (<=) :: ShowFmt a -> ShowFmt a -> Bool Source # (>) :: ShowFmt a -> ShowFmt a -> Bool Source # (>=) :: ShowFmt a -> ShowFmt a -> Bool Source # max :: ShowFmt a -> ShowFmt a -> ShowFmt a Source # min :: ShowFmt a -> ShowFmt a -> ShowFmt a Source #
Buildable a => Show ( ShowFmt a) Source #
Instance details Defined in Cardano.Wallet.Util Methods showsPrec :: Int -> ShowFmt a -> ShowS Source # show :: ShowFmt a -> String Source # showList :: [ ShowFmt a] -> ShowS Source #
Generic ( ShowFmt a) Source #
Instance details Defined in Cardano.Wallet.Util Associated Types type Rep ( ShowFmt a) :: Type -> Type Source # Methods from :: ShowFmt a -> Rep ( ShowFmt a) x Source # to :: Rep ( ShowFmt a) x -> ShowFmt a Source #
NFData a => NFData ( ShowFmt a) Source #
Instance details Defined in Cardano.Wallet.Util Methods rnf :: ShowFmt a -> () Source #
type Rep ( ShowFmt a) Source #
Instance details Defined in Cardano.Wallet.Util type Rep ( ShowFmt a) = D1 (' MetaData "ShowFmt" "Cardano.Wallet.Util" "cardano-wallet-core-2022.7.1-AGKhlyz9liLKN3QqZD1gj" ' True ) ( C1 (' MetaCons "ShowFmt" ' PrefixI ' True ) ( S1 (' MetaSel (' Just "unShowFmt") ' NoSourceUnpackedness ' NoSourceStrictness ' DecidedLazy ) ( Rec0 a)))

mapFirst :: (a -> a) -> [a] -> [a] Source #

Map a function to the first element of a list. Does nothing if the list is empty.

StateT

modifyM :: forall m s. Monad m => (s -> m s) -> StateT s m () Source #

Effectfully modify the state of a state-monad transformer stack.

HTTP(S) URIs

uriToText :: URI -> Text Source #

parseURI :: Text -> Either TextDecodingError URI Source #