Data.EDN

Encoding and decoding

decode :: FromEDN a => ByteString -> Maybe a

Deserializes a EDN value from a lazy ByteString. If this fails to to incomplete or invalid input, Nothing is returned.

encode :: ToEDN a => a -> ByteString

Serialize a value as a lazy ByteString.

Core EDN types

data Value

A "raw" EDN value represented as a Haskell value.

Constructors

Nil

Boolean !Bool

String !Text

Character !Char

Symbol !ByteString !ByteString

Keyword !ByteString

Integer !Integer

Floating !Double

List EDNList

Vec !EDNVec

Map !EDNMap

Set !EDNSet

Instances

Eq Value

Ord Value

Show Value

IsString Value

Strings starting with ":" will become keywords.

NFData Value

FromEDN Value

FromEDN TaggedValue

ToEDN Value

ToEDN TaggedValue

IsString (Tagged Value)

Strings will become an tagless EDN strings.

type TaggedValue = Tagged Value

data Tagged a

Abstract namespaced tag.

Constructors

NoTag !a

Tagged !a !ByteString !ByteString

Instances

Functor Tagged

FromEDN TaggedValue

ToEDN TaggedValue

Eq a => Eq (Tagged a)

Ord a => Ord (Tagged a)

Show a => Show (Tagged a)

IsString (Tagged Value)

Strings will become an tagless EDN strings.

NFData a => NFData (Tagged a)

FromEDN a => FromEDN (Tagged a)

ToEDN a => ToEDN (Tagged a)

Type conversion

class ToEDN a where

A type that can be converted to JSON.

Methods

toEDN :: a -> TaggedValue

Instances

ToEDN Bool

ToEDN Char

ToEDN Double

ToEDN Int

ToEDN Integer

ToEDN ()

ToEDN ByteString

ToEDN ByteString

ToEDN Text

ToEDN Text

ToEDN UTCTime

ToEDN Value

ToEDN TaggedValue

ToEDN [Char]

ToEDN a => ToEDN [a]

ToEDN a => ToEDN (Maybe a)

(Ord a, ToEDN a) => ToEDN (Set a)

ToEDN a => ToEDN (Vector a)

ToEDN a => ToEDN (Tagged a)

(ToEDN a, ToEDN b) => ToEDN (Either a b)

(ToEDN a, ToEDN b) => ToEDN (a, b)

(ToEDN a, ToEDN b) => ToEDN (Map a b)

(ToEDN a, ToEDN b, ToEDN c) => ToEDN (a, b, c)

(ToEDN a, ToEDN b, ToEDN c, ToEDN d) => ToEDN (a, b, c, d)

(ToEDN a, ToEDN b, ToEDN c, ToEDN d, ToEDN e) => ToEDN (a, b, c, d, e)

(ToEDN a, ToEDN b, ToEDN c, ToEDN d, ToEDN e, ToEDN f) => ToEDN (a, b, c, d, e, f)

(ToEDN a, ToEDN b, ToEDN c, ToEDN d, ToEDN e, ToEDN f, ToEDN g) => ToEDN (a, b, c, d, e, f, g)

(ToEDN a, ToEDN b, ToEDN c, ToEDN d, ToEDN e, ToEDN f, ToEDN g, ToEDN h) => ToEDN (a, b, c, d, e, f, g, h)

class FromEDN a

A type that can be converted from EDN, with a possibility of failure.

When writing an instance, use empty, mzero, or fail to make a conversion fail, e.g. if an Map is missing a required key, or the value is of the wrong type.

Instances

FromEDN Bool

FromEDN Char

FromEDN Double

FromEDN Int

FromEDN Integer

FromEDN ()

FromEDN ByteString

FromEDN ByteString

FromEDN Text

FromEDN Text

FromEDN UTCTime

FromEDN Value

FromEDN TaggedValue

FromEDN [Char]

FromEDN a => FromEDN [a]

FromEDN a => FromEDN (Maybe a)

(Ord a, FromEDN a) => FromEDN (Set a)

FromEDN a => FromEDN (Vector a)

FromEDN a => FromEDN (Tagged a)

(FromEDN a, FromEDN b) => FromEDN (Either a b)

(FromEDN a, FromEDN b) => FromEDN (a, b)

(Ord a, FromEDN a, FromEDN b) => FromEDN (Map a b)

(FromEDN a, FromEDN b, FromEDN c) => FromEDN (a, b, c)

(FromEDN a, FromEDN b, FromEDN c, FromEDN d) => FromEDN (a, b, c, d)

(FromEDN a, FromEDN b, FromEDN c, FromEDN d, FromEDN e) => FromEDN (a, b, c, d, e)

(FromEDN a, FromEDN b, FromEDN c, FromEDN d, FromEDN e, FromEDN f) => FromEDN (a, b, c, d, e, f)

(FromEDN a, FromEDN b, FromEDN c, FromEDN d, FromEDN e, FromEDN f, FromEDN g) => FromEDN (a, b, c, d, e, f, g)

(FromEDN a, FromEDN b, FromEDN c, FromEDN d, FromEDN e, FromEDN f, FromEDN g, FromEDN h) => FromEDN (a, b, c, d, e, f, g, h)

fromEDN :: FromEDN a => TaggedValue -> Result a

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

fromEDNv :: FromEDN a => Value -> Result a

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

(.:) :: (Show k, ToEDN k, FromEDN a) => EDNMap -> k -> Parser a

Retrieve the value associated with the given key of an EDNMap. The result is empty if the key is not present or the value cannot be converted to the desired type.

This accessor is appropriate if the key and value must be present in an object for it to be valid. If the key and value are optional, use '(.:?)' instead.

(.:?) :: (ToEDN k, FromEDN a) => EDNMap -> k -> Parser (Maybe a)

Retrieve the value associated with the given key of an EDNMap. The result is Nothing if the key is not present, or empty if the value cannot be converted to the desired type.

This accessor is most useful if the key and value can be absent from an object without affecting its validity. If the key and value are mandatory, use '(.:)' instead.

(.!=) :: Parser (Maybe a) -> a -> Parser a

Helper for use in combination with .:? to provide default values for optional JSON object fields.

This combinator is most useful if the key and value can be absent from an object without affecting its validity and we know a default value to assign in that case. If the key and value are mandatory, use '(.:)' instead.

Example usage:

 v1 <- o .:? "opt_field_with_dfl" .!= "default_val"
 v2 <- o .:  "mandatory_field"
 v3 <- o .:? "opt_field2"

Constructors

tag :: ByteString -> ByteString -> a -> Tagged a

Attach a namespaced tag to a value.

notag :: a -> Tagged a

Wrap a value into tagless container.

Basic values

nil :: TaggedValue

Basic EDN nil.

bool :: Bool -> TaggedValue

Basic EDN boolean.

true :: TaggedValue

Const EDN True.

false :: TaggedValue

Const EDN False.

char :: Char -> TaggedValue

Basic EDN character.

string :: Text -> TaggedValue

Basic EDN string.

symbol :: ByteString -> TaggedValue

"Bare" symbol.

symbolNS :: ByteString -> ByteString -> TaggedValue

A namespaced symbol.

keyword :: ByteString -> TaggedValue

Basic EDN keyword.

integer :: Integer -> TaggedValue

Basic EDN integer.

floating :: Double -> TaggedValue

Basic EDN fp number.

Containers

makeList :: [TaggedValue] -> Value

Create an EDN List from a Value list wrapping them into empty tags.

makeVec :: [TaggedValue] -> Value

Create an EDN Vector from a TaggedValue list.

makeSet :: [TaggedValue] -> Value

Create an EDN Set from a TaggedValue list.

makeMap :: [Pair] -> Value

Create an EDN Map from a assoc list with untagged keys and tagged values.

type Pair = (Value, TaggedValue)

A key/value pair for a EDN Map

(.=) :: ToEDN a => ByteString -> a -> Pair

Construct a Pair from a key (as EDN keyword) and a value.

Tag manipulation

setTag :: ByteString -> ByteString -> Tagged a -> Tagged a

Replace a tag on a Tagged value.

getTag :: TaggedValue -> (ByteString, ByteString)

Extract namespace and tag from a tagged container. Will be a pair of empty for tagless containers.

stripTag :: Tagged a -> a

Extract bare value from a tagged or tagless container.

Parsing

parseMaybe :: ByteString -> Maybe TaggedValue

Parse a lazy ByteString into a TaggedValue. If fails due to incomplete or invalid input, Nothing is returned.