Maintainer	Leon P Smith <leon@melding-monads.com>
Safe Haskell	None

Data.Configurator.FromValue

Contents

Assorted primitive value parsers

Description

Synopsis

Documentation

data MaybeParser a Source

An action to turn a Maybe Value into zero or one values of type a, and possibly report errors/warnings.

Instances

Monad MaybeParser
Functor MaybeParser
Typeable1 MaybeParser
Applicative MaybeParser
Alternative MaybeParser
MonadFail MaybeParser

runMaybeParser :: MaybeParser a -> Maybe Value -> (Maybe a, [ConversionError])Source

class FromMaybeValue a whereSource

Methods

fromMaybeValue :: MaybeParser aSource

Instances

FromMaybeValue Bool
FromMaybeValue Char
FromMaybeValue Double
FromMaybeValue Float
FromMaybeValue Int
FromMaybeValue Int8
FromMaybeValue Int16
FromMaybeValue Int32
FromMaybeValue Int64
FromMaybeValue Integer
FromMaybeValue Word
FromMaybeValue Word8
FromMaybeValue Word16
FromMaybeValue Word32
FromMaybeValue Word64
FromMaybeValue String
FromMaybeValue ByteString
FromMaybeValue ByteString
FromMaybeValue Text
FromMaybeValue Text
FromMaybeValue CFloat
FromMaybeValue CDouble
FromMaybeValue Scientific
FromMaybeValue Value
(Typeable a, FromValue a) => FromMaybeValue [a]
(Typeable a, Integral a) => FromMaybeValue (Ratio a)
FromValue a => FromMaybeValue (Maybe a)
(Typeable a, HasResolution a) => FromMaybeValue (Fixed a)
(Typeable a, RealFloat a) => FromMaybeValue (Complex a)
(Typeable a, FromValue a, Typeable b, FromValue b) => FromMaybeValue (a, b)
(Typeable a, FromValue a, Typeable b, FromValue b, Typeable c, FromValue c) => FromMaybeValue (a, b, c)
(Typeable a, FromValue a, Typeable b, FromValue b, Typeable c, FromValue c, Typeable d, FromValue d) => FromMaybeValue (a, b, c, d)

optionalValue :: ValueParser a -> MaybeParser (Maybe a)Source

Turns a ValueParser into a MaybeParser. If the Maybe Value the parser is passed is Nothing (which normally means a key was not found), then this returns the Nothing value with no errors or warnings. Otherwise, it passes the Value to the subparser. If the subparser returns a result value, then this returns Just the value. Otherwise, if the subparser does not return a value, then this does not return a value.

Any errors/warnings returned by the subparser are returned exactly as-is.

requiredValue :: forall a. Typeable a => ValueParser a -> MaybeParser aSource

Turns a ValueParser into a MaybeParser. If the Maybe Value the parser is passed is Nothing (which normally means a key was not found), then this does not return a value and also returns a missingValueError. Otherwise, the Value is passed to the subparser, and the result and any errors/warnings are returned as-is.

data ValueParser a Source

An action to turn a Value into zero or one values of type a, and possibly report errors/warnings.

Instances

Monad ValueParser
Functor ValueParser
Typeable1 ValueParser
Applicative ValueParser
Alternative ValueParser
MonadFail ValueParser

runValueParser :: ValueParser a -> Value -> (Maybe a, [ConversionError])Source

class FromValue a whereSource

Methods

fromValue :: ValueParser aSource

Instances

FromValue Bool
FromValue Char
FromValue Double
FromValue Float
FromValue Int
FromValue Int8
FromValue Int16
FromValue Int32
FromValue Int64
FromValue Integer
FromValue Word
FromValue Word8
FromValue Word16
FromValue Word32
FromValue Word64
FromValue String
FromValue ByteString
FromValue ByteString
FromValue Text
FromValue Text
FromValue CFloat
FromValue CDouble
FromValue Scientific
FromValue Value
(Typeable a, FromValue a) => FromValue [a]
(Typeable a, Integral a) => FromValue (Ratio a)
(Typeable a, HasResolution a) => FromValue (Fixed a)
(Typeable a, RealFloat a) => FromValue (Complex a)
(Typeable a, FromValue a, Typeable b, FromValue b) => FromValue (a, b)
(Typeable a, FromValue a, Typeable b, FromValue b, Typeable c, FromValue c) => FromValue (a, b, c)
(Typeable a, FromValue a, Typeable b, FromValue b, Typeable c, FromValue c, Typeable d, FromValue d) => FromValue (a, b, c, d)

data ListParser a Source

An action to turn a [Value] into zero or one values of type a, and possibly report errors/warnings.

Instances

Monad ListParser
Functor ListParser
Typeable1 ListParser
Applicative ListParser
Alternative ListParser
MonadFail ListParser

class FromListValue a whereSource

Methods

fromListValue :: ListParser aSource

Instances

(Typeable a, FromValue a, Typeable b, FromValue b) => FromListValue (a, b)
(Typeable a, FromValue a, Typeable b, FromValue b, Typeable c, FromValue c) => FromListValue (a, b, c)
(Typeable a, FromValue a, Typeable b, FromValue b, Typeable c, FromValue c, Typeable d, FromValue d) => FromListValue (a, b, c, d)

listValue :: forall a. Typeable a => ListParser a -> ValueParser aSource

Turns a ListParser into a ValueParser. It first checks that the Value the ValueParser is passed is a List Value. If it's not, this returns no result as well as a typeError. Otherwise, it passes the list of results to the ListParser subparser.

If the subparser consumes all of the list elements, this returns the value and errors as-is. If there are leftover list elements, this returns the value, and adds a message warning of the extra elements to the list of errors.

The difference from 'listValue\'' is that this returns values with unconsumed list elements (discarding the list elements).

listValue' :: forall a. Typeable a => ListParser a -> ValueParser aSource

Turns a ListParser into a ValueParser. It first checks that the Value the ValueParser is passed is a List Value. If it's not, this returns no result as well as a typeError. Otherwise, it passes the list of results to the ListParser subparser.

If the subparser consumes all of the list elements, this returns the value and errors as-is. If there are leftover list elements, this returns no value, and adds a message warning of the extra elements to the list of errors.

The difference from listValue is that this never returns a value if there are unconsumed list elements. (discarding both the value returned and the list element.)

listElem :: forall a. Typeable a => ValueParser a -> ListParser aSource

Turns a ValueParser into a ListParser that consumes a single element.

If there are no list elements left, this returns list error value and an ExhaustedValues error.

If there is an element left, it is passed to the value parser. If the value parser returns a value, it is returned along with the errors as-is. If the value parser returns no value, then this returns a non-list error value and the list of errors returned by the value parser.

The difference between a list error value and a non-list error value, is that the Alternative instance for ListParser recovers from list error values but does not recover from non-list error values. This behavior was chosen so that the optional, some, and many combinators work on ListParsers in a way that is hopefully least surprising.

data ConversionError Source

Constructors

ConversionError
Fields conversionErrorLoc :: Text conversionErrorWhy :: ConversionErrorWhy conversionErrorVal :: !(Maybe Value) conversionErrorType :: !(Maybe TypeRep) conversionErrorMsg :: !(Maybe Text)