Waargonaut.Decode.Internal

Internal types and functions for building Decoder infrastructure.

Documentation

newtype CursorHistory' i

Track the history of the cursor as we move around the zipper.

It is indexed over the type of the index used to navigate the zipper.

Constructors

CursorHistory'

Fields

• unCursorHistory' :: Seq (ZipperMove, i)

Instances

Monad f => MonadState CursorHistory (DecodeResult f)

Defined in Waargonaut.Decode.Types

Methods

get :: DecodeResult f CursorHistory

put :: CursorHistory -> DecodeResult f ()

state :: (CursorHistory -> (a, CursorHistory)) -> DecodeResult f a

Eq i => Eq (CursorHistory' i)

Defined in Waargonaut.Decode.Internal

Methods

(==) :: CursorHistory' i -> CursorHistory' i -> Bool

(/=) :: CursorHistory' i -> CursorHistory' i -> Bool

Show i => Show (CursorHistory' i)

Defined in Waargonaut.Decode.Internal

Methods

showsPrec :: Int -> CursorHistory' i -> ShowS

show :: CursorHistory' i -> String

showList :: [CursorHistory' i] -> ShowS

Wrapped (CursorHistory' i)

Defined in Waargonaut.Decode.Internal

Associated Types

type Unwrapped (CursorHistory' i) :: *

Methods

_Wrapped' :: Iso' (CursorHistory' i) (Unwrapped (CursorHistory' i))

CursorHistory' i ~ t => Rewrapped (CursorHistory' i) t

Defined in Waargonaut.Decode.Internal

Monad f => MonadState (CursorHistory' Int) (DecodeResult f)

Defined in Waargonaut.Decode.Traversal

Methods

get :: DecodeResult f (CursorHistory' Int)

put :: CursorHistory' Int -> DecodeResult f ()

state :: (CursorHistory' Int -> (a, CursorHistory' Int)) -> DecodeResult f a

Monad f => MonadState (CursorHistory' i) (DecodeResultT i e f)

Defined in Waargonaut.Decode.Internal

Methods

get :: DecodeResultT i e f (CursorHistory' i)

put :: CursorHistory' i -> DecodeResultT i e f ()

state :: (CursorHistory' i -> (a, CursorHistory' i)) -> DecodeResultT i e f a

type Unwrapped (CursorHistory' i)

Defined in Waargonaut.Decode.Internal

type Unwrapped (CursorHistory' i) = Seq (ZipperMove, i)

ppCursorHistory :: CursorHistory' i -> Doc a

Pretty print the given CursorHistory' to a more useful format compared to a Seq of i.

newtype DecodeResultT i e f a

The general structure used to maintain the history of the moves around the zipper, as well as handle the decoding or movement errors that may occur. This structure is generalised of the inner f to allow you to interleave the decoding with your own actions. As well as the error type e so that you may provide your own error type.

If you use the provided Decode module then you probably won't need to care about this type. It is provided so that you're not limited to how we decide you should be running your decoder.

Constructors

DecodeResultT

Fields

• runDecodeResult :: ExceptT e (StateT (CursorHistory' i) f) a

Instances

Monad f => MonadError e (DecodeResultT i e f)

Defined in Waargonaut.Decode.Internal

Methods

throwError :: e -> DecodeResultT i e f a

catchError :: DecodeResultT i e f a -> (e -> DecodeResultT i e f a) -> DecodeResultT i e f a

MFunctor (DecodeResultT i e :: (* -> *) -> * -> *)

Defined in Waargonaut.Decode.Internal

Methods

hoist :: Monad m => (forall a. m a -> n a) -> DecodeResultT i e m b -> DecodeResultT i e n b

Monad f => MonadState (CursorHistory' i) (DecodeResultT i e f)

Defined in Waargonaut.Decode.Internal

Methods

get :: DecodeResultT i e f (CursorHistory' i)

put :: CursorHistory' i -> DecodeResultT i e f ()

state :: (CursorHistory' i -> (a, CursorHistory' i)) -> DecodeResultT i e f a

MMonad (DecodeResultT i e)

Defined in Waargonaut.Decode.Internal

Methods

embed :: Monad n => (forall a. m a -> DecodeResultT i e n a) -> DecodeResultT i e m b -> DecodeResultT i e n b

MonadTrans (DecodeResultT i e)

Defined in Waargonaut.Decode.Internal

Methods

lift :: Monad m => m a -> DecodeResultT i e m a

Monad f => Monad (DecodeResultT i e f)

Defined in Waargonaut.Decode.Internal

Methods

(>>=) :: DecodeResultT i e f a -> (a -> DecodeResultT i e f b) -> DecodeResultT i e f b

(>>) :: DecodeResultT i e f a -> DecodeResultT i e f b -> DecodeResultT i e f b

return :: a -> DecodeResultT i e f a

fail :: String -> DecodeResultT i e f a

Functor f => Functor (DecodeResultT i e f)

Defined in Waargonaut.Decode.Internal

Methods

fmap :: (a -> b) -> DecodeResultT i e f a -> DecodeResultT i e f b

(<$) :: a -> DecodeResultT i e f b -> DecodeResultT i e f a

Monad f => Applicative (DecodeResultT i e f)

Defined in Waargonaut.Decode.Internal

Methods

pure :: a -> DecodeResultT i e f a

(<*>) :: DecodeResultT i e f (a -> b) -> DecodeResultT i e f a -> DecodeResultT i e f b

liftA2 :: (a -> b -> c) -> DecodeResultT i e f a -> DecodeResultT i e f b -> DecodeResultT i e f c

(*>) :: DecodeResultT i e f a -> DecodeResultT i e f b -> DecodeResultT i e f b

(<*) :: DecodeResultT i e f a -> DecodeResultT i e f b -> DecodeResultT i e f a

newtype Decoder' c i e f a

Wrapper type to describe a Decoder from something that has a Jsonish value c, to some representation of a.

Constructors

Decoder'

Fields

• runDecoder' :: c -> DecodeResultT i e f a

Instances

MFunctor (Decoder' c i e :: (* -> *) -> * -> *)

Defined in Waargonaut.Decode.Internal

Methods

hoist :: Monad m => (forall a. m a -> n a) -> Decoder' c i e m b -> Decoder' c i e n b

MonadTrans (Decoder' c i e)

Defined in Waargonaut.Decode.Internal

Methods

lift :: Monad m => m a -> Decoder' c i e m a

Monad f => Monad (Decoder' c i e f)

Defined in Waargonaut.Decode.Internal

Methods

(>>=) :: Decoder' c i e f a -> (a -> Decoder' c i e f b) -> Decoder' c i e f b

(>>) :: Decoder' c i e f a -> Decoder' c i e f b -> Decoder' c i e f b

return :: a -> Decoder' c i e f a

fail :: String -> Decoder' c i e f a

Functor f => Functor (Decoder' c i e f)

Defined in Waargonaut.Decode.Internal

Methods

fmap :: (a -> b) -> Decoder' c i e f a -> Decoder' c i e f b

(<$) :: a -> Decoder' c i e f b -> Decoder' c i e f a

Monad f => Applicative (Decoder' c i e f)

Defined in Waargonaut.Decode.Internal

Methods

pure :: a -> Decoder' c i e f a

(<*>) :: Decoder' c i e f (a -> b) -> Decoder' c i e f a -> Decoder' c i e f b

liftA2 :: (a -> b -> c0) -> Decoder' c i e f a -> Decoder' c i e f b -> Decoder' c i e f c0

(*>) :: Decoder' c i e f a -> Decoder' c i e f b -> Decoder' c i e f b

(<*) :: Decoder' c i e f a -> Decoder' c i e f b -> Decoder' c i e f a

withCursor' :: (c -> DecodeResultT i e f a) -> Decoder' c i e f a

Helper function for constructing a Decoder'.

This function is used by the implemented decoders to simplify constructing a more specific Decoder type.

withCursor' $ curs ->
  ...
  ...

runDecoderResultT :: Monad f => DecodeResultT i DecodeError f a -> f (Either (DecodeError, CursorHistory' i) a)

Execute a given DecoderResultT.

If you're building your own decoder structure, this function will take care of the CursorHistory' and error handling (via ExceptT).

try :: MonadError e m => m a -> m (Maybe a)

Attempt a Decoder action that might fail and return a Maybe value instead.

recordZipperMove :: MonadState (CursorHistory' i) m => ZipperMove -> i -> m ()

Record a move on the zipper and the index of the position where the move occured.

Generalised Decoder Functions

null' :: AsJType a ws a => a -> Maybe ()

Try to decode a null value from some Json value

int' :: AsJType a ws a => a -> Maybe Int

Try to decode an Int from some Json value

text' :: AsJType a ws a => a -> Maybe Text

Try to decode a Text value from some Json or value.

string' :: AsJType a ws a => a -> Maybe String

Try to decode a String value from some Json or value.

unboundedChar' :: AsJType a ws a => a -> Maybe Char

Decoder for a Haskell Char value whose values represent Unicode (or equivalently ISO/IEC 10646) characters

boundedChar' :: AsJType a ws a => a -> Maybe Char

Decoder for a Char value that cannot contain values in the range U+D800 to U+DFFF. This decoder will fail if the Char is outside of this range.

bool' :: AsJType a ws a => a -> Maybe Bool

Try to decode a Bool from some Json value

array' :: AsJType a ws a => (a -> Maybe b) -> a -> [b]

Combined with another decoder function f, try to decode a list of a values.

array' int' :: Json -> [Int]

integral' :: (Bounded i, Integral i, AsJType a ws a) => a -> Maybe i

Try to decode a bounded 'Integral n => n' value from some Json value.

scientific' :: AsJType a ws a => a -> Maybe Scientific

Try to decode a Scientific value from some Json or value.

objTuples' :: (Applicative f, AsJType a ws a) => (JString -> f k) -> (a -> f b) -> a -> f [(k, b)]

Try to decode a JSON Object into it's representative list of tuples '(key, value)'. The JSON RFC does not specify that an object must contain unique keys. We do not enforce unique keys during the decoding process and leave it to the user to decide if, and how, they would like to handle this situation.

foldCursor' :: Monad f => b -> (b -> a -> b) -> (c -> DecodeResultT i e f c) -> Decoder' c i e f a -> c -> DecodeResultT i e f b

Generalised moving decoder function.

Starting from the given cursor position, try to move in the direction specified by the given cursor function. Attempting to decode each item at each position using the given Decoder, until the movement is unsuccessful.

The following could be used to leverage the Snoc instance of '[]' to build '[Int]'.

intList :: Monad f => JCurs -> DecodeResult f [Int]
intList = directedConsumption' snoc moveRight1 int

prismDOrFail' :: (AsDecodeError e, MonadError e f) => e -> Prism' a b -> Decoder' c i e f a -> c -> DecodeResultT i e f b

Build the basis for a Decoder based on a Prism'.

JSON Object to Map Functions

mapKeepingF :: (Ord k, Applicative f, AsJType a ws a) => (t -> Maybe v -> Maybe v) -> (JString -> f k) -> (a -> f t) -> a -> f (Map k v)

Provide a generalised and low level way of turning a JSON object into a Map, without enforcing a choice of how we select keys.

mapKeepingFirst :: (Ord k, Applicative f, AsJType a ws a) => (JString -> f k) -> (a -> f b) -> a -> f (Map k b)

Turn a JSON object into a Map by keeping the *first* occurence of any duplicate keys that are encountered.

mapKeepingLast :: (Ord k, Applicative f, AsJType a ws a) => (JString -> f k) -> (a -> f b) -> a -> f (Map k b)

Turn a JSON object into a Map by keeping the *last* occurence of any duplicate keys that are encountered.

Re-exports

class AsDecodeError r where

Describes the sorts of errors that may be treated as a DecodeError, for use with lens.

Minimal complete definition

_DecodeError

Methods

_DecodeError :: Prism' r DecodeError

_ConversionFailure :: Prism' r Text

_KeyDecodeFailed :: Prism' r ()

_KeyNotFound :: Prism' r Text

_FailedToMove :: Prism' r ZipperMove

_NumberOutOfBounds :: Prism' r JNumber

_InputOutOfBounds :: Prism' r Word64

_ParseFailed :: Prism' r Text

Instances

AsDecodeError DecodeError

Defined in Waargonaut.Decode.Error

Methods

_DecodeError :: Prism' DecodeError DecodeError

_ConversionFailure :: Prism' DecodeError Text

_KeyDecodeFailed :: Prism' DecodeError ()

_KeyNotFound :: Prism' DecodeError Text

_FailedToMove :: Prism' DecodeError ZipperMove

_NumberOutOfBounds :: Prism' DecodeError JNumber

_InputOutOfBounds :: Prism' DecodeError Word64

_ParseFailed :: Prism' DecodeError Text

data DecodeError

Set of errors that may occur during the decode phase.

Constructors

ConversionFailure Text

KeyDecodeFailed

KeyNotFound Text

FailedToMove ZipperMove

NumberOutOfBounds JNumber

InputOutOfBounds Word64

ParseFailed Text

Instances

Eq DecodeError

Defined in Waargonaut.Decode.Error

Methods

(==) :: DecodeError -> DecodeError -> Bool

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

Show DecodeError

Defined in Waargonaut.Decode.Error

Methods

showsPrec :: Int -> DecodeError -> ShowS

show :: DecodeError -> String

showList :: [DecodeError] -> ShowS

AsDecodeError DecodeError

Defined in Waargonaut.Decode.Error

Methods

_DecodeError :: Prism' DecodeError DecodeError

_ConversionFailure :: Prism' DecodeError Text

_KeyDecodeFailed :: Prism' DecodeError ()

_KeyNotFound :: Prism' DecodeError Text

_FailedToMove :: Prism' DecodeError ZipperMove

_NumberOutOfBounds :: Prism' DecodeError JNumber

_InputOutOfBounds :: Prism' DecodeError Word64

_ParseFailed :: Prism' DecodeError Text

Monad f => MonadReader ParseFn (DecodeResult f)

Defined in Waargonaut.Decode.Types

Methods

ask :: DecodeResult f ParseFn

local :: (ParseFn -> ParseFn) -> DecodeResult f a -> DecodeResult f a

reader :: (ParseFn -> a) -> DecodeResult f a

Monad f => MonadError DecodeError (DecodeResult f)

Defined in Waargonaut.Decode.Types

Methods

throwError :: DecodeError -> DecodeResult f a

catchError :: DecodeResult f a -> (DecodeError -> DecodeResult f a) -> DecodeResult f a

Monad f => MonadError DecodeError (Decoder f)

Defined in Waargonaut.Decode.Types

Methods

throwError :: DecodeError -> Decoder f a

catchError :: Decoder f a -> (DecodeError -> Decoder f a) -> Decoder f a

Monad f => MonadError DecodeError (DecodeResult f)

Defined in Waargonaut.Decode.Traversal

Methods

throwError :: DecodeError -> DecodeResult f a

catchError :: DecodeResult f a -> (DecodeError -> DecodeResult f a) -> DecodeResult f a

data ZipperMove

Set of moves that may be executed on a zipper.

Constructors

U

D

DAt Text

Item Text

L Natural

R Natural

BranchFail Text

Instances

Eq ZipperMove

Defined in Waargonaut.Decode.ZipperMove

Methods

(==) :: ZipperMove -> ZipperMove -> Bool

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

Show ZipperMove

Defined in Waargonaut.Decode.ZipperMove

Methods

showsPrec :: Int -> ZipperMove -> ShowS

show :: ZipperMove -> String

showList :: [ZipperMove] -> ShowS

AsZipperMove ZipperMove

Defined in Waargonaut.Decode.ZipperMove

Methods

_ZipperMove :: Prism' ZipperMove ZipperMove

_U :: Prism' ZipperMove ()

_D :: Prism' ZipperMove ()

_DAt :: Prism' ZipperMove Text

_Item :: Prism' ZipperMove Text

_L :: Prism' ZipperMove Natural

_R :: Prism' ZipperMove Natural

ppZipperMove :: ZipperMove -> Doc a

Pretty print a given zipper movement, used when printing CursorHistory' to improve the readability of the errors.