Data.Aeson.Internal

Internal types and functions.

Note: all declarations in this module are unstable, and prone to being changed at any time.

Documentation

data IResult a

The internal result of running a Parser.

Constructors

IError JSONPath String

ISuccess a

Instances

Monad IResult

Defined in Data.Aeson.Types.Internal

Methods

(>>=) :: IResult a -> (a -> IResult b) -> IResult b

(>>) :: IResult a -> IResult b -> IResult b

return :: a -> IResult a

Functor IResult

Defined in Data.Aeson.Types.Internal

Methods

fmap :: (a -> b) -> IResult a -> IResult b

(<$) :: a -> IResult b -> IResult a

MonadFail IResult

Defined in Data.Aeson.Types.Internal

Methods

fail :: String -> IResult a

Applicative IResult

Defined in Data.Aeson.Types.Internal

Methods

pure :: a -> IResult a

(<*>) :: IResult (a -> b) -> IResult a -> IResult b

liftA2 :: (a -> b -> c) -> IResult a -> IResult b -> IResult c

(*>) :: IResult a -> IResult b -> IResult b

(<*) :: IResult a -> IResult b -> IResult a

Foldable IResult

Defined in Data.Aeson.Types.Internal

Methods

fold :: Monoid m => IResult m -> m

foldMap :: Monoid m => (a -> m) -> IResult a -> m

foldMap' :: Monoid m => (a -> m) -> IResult a -> m

foldr :: (a -> b -> b) -> b -> IResult a -> b

foldr' :: (a -> b -> b) -> b -> IResult a -> b

foldl :: (b -> a -> b) -> b -> IResult a -> b

foldl' :: (b -> a -> b) -> b -> IResult a -> b

foldr1 :: (a -> a -> a) -> IResult a -> a

foldl1 :: (a -> a -> a) -> IResult a -> a

toList :: IResult a -> [a]

null :: IResult a -> Bool

length :: IResult a -> Int

elem :: Eq a => a -> IResult a -> Bool

maximum :: Ord a => IResult a -> a

minimum :: Ord a => IResult a -> a

sum :: Num a => IResult a -> a

product :: Num a => IResult a -> a

Traversable IResult

Defined in Data.Aeson.Types.Internal

Methods

traverse :: Applicative f => (a -> f b) -> IResult a -> f (IResult b)

sequenceA :: Applicative f => IResult (f a) -> f (IResult a)

mapM :: Monad m => (a -> m b) -> IResult a -> m (IResult b)

sequence :: Monad m => IResult (m a) -> m (IResult a)

Alternative IResult

Defined in Data.Aeson.Types.Internal

Methods

empty :: IResult a

(<|>) :: IResult a -> IResult a -> IResult a

some :: IResult a -> IResult [a]

many :: IResult a -> IResult [a]

MonadPlus IResult

Defined in Data.Aeson.Types.Internal

Methods

mzero :: IResult a

mplus :: IResult a -> IResult a -> IResult a

Eq a => Eq (IResult a)

Defined in Data.Aeson.Types.Internal

Methods

(==) :: IResult a -> IResult a -> Bool

(/=) :: IResult a -> IResult a -> Bool

Show a => Show (IResult a)

Defined in Data.Aeson.Types.Internal

Methods

showsPrec :: Int -> IResult a -> ShowS

show :: IResult a -> String

showList :: [IResult a] -> ShowS

Semigroup (IResult a)

Defined in Data.Aeson.Types.Internal

Methods

(<>) :: IResult a -> IResult a -> IResult a

sconcat :: NonEmpty (IResult a) -> IResult a

stimes :: Integral b => b -> IResult a -> IResult a

Monoid (IResult a)

Defined in Data.Aeson.Types.Internal

Methods

mempty :: IResult a

mappend :: IResult a -> IResult a -> IResult a

mconcat :: [IResult a] -> IResult a

NFData a => NFData (IResult a)

Defined in Data.Aeson.Types.Internal

Methods

rnf :: IResult a -> ()

data JSONPathElement

Elements of a JSON path used to describe the location of an error.

Constructors

Key Text

JSON path element of a key into an object, "object.key".

Index !Int

JSON path element of an index into an array, "array[index]".

Instances

Eq JSONPathElement

Defined in Data.Aeson.Types.Internal

Methods

(==) :: JSONPathElement -> JSONPathElement -> Bool

(/=) :: JSONPathElement -> JSONPathElement -> Bool

Ord JSONPathElement

Defined in Data.Aeson.Types.Internal

Methods

compare :: JSONPathElement -> JSONPathElement -> Ordering

(<) :: JSONPathElement -> JSONPathElement -> Bool

(<=) :: JSONPathElement -> JSONPathElement -> Bool

(>) :: JSONPathElement -> JSONPathElement -> Bool

(>=) :: JSONPathElement -> JSONPathElement -> Bool

max :: JSONPathElement -> JSONPathElement -> JSONPathElement

min :: JSONPathElement -> JSONPathElement -> JSONPathElement

Show JSONPathElement

Defined in Data.Aeson.Types.Internal

Methods

showsPrec :: Int -> JSONPathElement -> ShowS

show :: JSONPathElement -> String

showList :: [JSONPathElement] -> ShowS

NFData JSONPathElement

Defined in Data.Aeson.Types.Internal

Methods

rnf :: JSONPathElement -> ()

type JSONPath = [JSONPathElement]

(<?>) :: Parser a -> JSONPathElement -> Parser a

Add JSON Path context to a parser

When parsing a complex structure, it helps to annotate (sub)parsers with context, so that if an error occurs, you can find its location.

withObject "Person" $ \o ->
  Person
    <$> o .: "name" <?> Key "name"
    <*> o .: "age"  <?> Key "age"

(Standard methods like (.:) already do this.)

With such annotations, if an error occurs, you will get a JSON Path location of that error.

Since 0.10

formatError :: JSONPath -> String -> String

Annotate an error message with a JSONPath error location.

ifromJSON :: FromJSON a => Value -> IResult a

Convert a value from JSON, failing if the types do not match.

iparse :: (a -> Parser b) -> a -> IResult b

Run a Parser.