Safe Haskell	Safe-Inferred
Language	Haskell2010

Json

Contents

Types
Classes
Functions
Infix Synonyms
Constants
Value Construction
Array Construction
Object Construction

Synopsis

data Value
- = Object !(SmallArray Member)
- | Array !(SmallArray Value)
- | String !ShortText
- | Number !Scientific
- | Null
- | True
- | False
data Member = Member {
- key :: !ShortText
- value :: !Value
}
data SyntaxException
- = EmptyInput
- | ExpectedColon
- | ExpectedCommaOrRightBracket
- | ExpectedFalse
- | ExpectedNull
- | ExpectedQuote
- | ExpectedQuoteOrRightBrace
- | ExpectedTrue
- | IncompleteArray
- | IncompleteEscapeSequence
- | IncompleteObject
- | IncompleteString
- | InvalidEscapeSequence
- | InvalidLeader
- | InvalidNumber
- | LeadingZero
- | UnexpectedLeftovers
- | PossibleOverflow
class ToValue a where
- toValue :: a -> Value
decode :: Bytes -> Either SyntaxException Value
decodeNewlineDelimited :: Bytes -> Either SyntaxException (SmallArray Value)
encode :: Value -> Builder
toChunks :: Value -> Chunks
toShortText :: Value -> ShortText
toText :: Value -> Text
toBytes :: Value -> Bytes
toByteArray :: Value -> ByteArray
pattern (:->) :: ShortText -> Value -> Member
emptyArray :: Value
emptyObject :: Value
int :: Int -> Value
int8 :: Int8 -> Value
int16 :: Int16 -> Value
int32 :: Int32 -> Value
int64 :: Int64 -> Value
word8 :: Word8 -> Value
word16 :: Word16 -> Value
word32 :: Word32 -> Value
word64 :: Word64 -> Value
bool :: Bool -> Value
text :: Text -> Value
shortText :: ShortText -> Value
arrayFromList :: [Value] -> Value
objectFromList :: [Member] -> Value
object1 :: Member -> Value
object2 :: Member -> Member -> Value
object3 :: Member -> Member -> Member -> Value
object4 :: Member -> Member -> Member -> Member -> Value
object5 :: Member -> Member -> Member -> Member -> Member -> Value
object6 :: Member -> Member -> Member -> Member -> Member -> Member -> Value
object7 :: Member -> Member -> Member -> Member -> Member -> Member -> Member -> Value
object8 :: Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Value
object9 :: Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Value
object10 :: Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Value
object11 :: Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Value
object12 :: Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Value
object13 :: Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Value
object14 :: Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Value
object15 :: Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Value
object16 :: Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Member -> Value

Types

data Value Source #

The JSON syntax tree described by the ABNF in RFC 7159. Notable design decisions include:

True and False are their own data constructors rather than being lumped together under a data constructor for boolean values. This improves performance when decoding the syntax tree to a Bool.
Object uses an association list rather than a hash map. This is the data type that key-value pairs can be parsed into most cheaply.
Object and Array both use Chunks rather than using SmallArray or cons-list directly. This a middle ground between those two types. We get the efficent use of cache lines that SmallArray offers, and we get the worst-case O(1) appends that cons-list offers. Users will typically fold over the elements with the Foldable instance of Chunks, although there are functions in Data.Chunks that efficently perform other operations.

Constructors

Object !(SmallArray Member)
Array !(SmallArray Value)
String !ShortText
Number !Scientific
Null
True
False

Instances

Instances details

Show Value Source #
Instance details Defined in Json Methods showsPrec :: Int -> Value -> ShowS # show :: Value -> String # showList :: [Value] -> ShowS #
Eq Value Source #
Instance details Defined in Json Methods (==) :: Value -> Value -> Bool # (/=) :: Value -> Value -> Bool #
ToValue Value Source #
Instance details Defined in Json Methods toValue :: Value -> Value Source #

data Member Source #

A key-value pair in a JSON object. The name of this type is taken from section 4 of RFC 7159.

Constructors

Member
Fields key :: !ShortText value :: !Value

Instances

Instances details

Show Member Source #
Instance details Defined in Json Methods showsPrec :: Int -> Member -> ShowS # show :: Member -> String # showList :: [Member] -> ShowS #
Eq Member Source #
Instance details Defined in Json Methods (==) :: Member -> Member -> Bool # (/=) :: Member -> Member -> Bool #

data SyntaxException Source #

Exceptions that can happen while parsing JSON. Do not pattern match on values of this type. New data constructors may be added at any time without a major version bump.

Constructors

EmptyInput
ExpectedColon
ExpectedCommaOrRightBracket
ExpectedFalse
ExpectedNull
ExpectedQuote
ExpectedQuoteOrRightBrace
ExpectedTrue
IncompleteArray
IncompleteEscapeSequence
IncompleteObject
IncompleteString
InvalidEscapeSequence
InvalidLeader
InvalidNumber
LeadingZero
UnexpectedLeftovers
PossibleOverflow

Instances

Instances details

Exception SyntaxException Source #
Instance details Defined in Json Methods toException :: SyntaxException -> SomeException # fromException :: SomeException -> Maybe SyntaxException # displayException :: SyntaxException -> String #
Show SyntaxException Source #
Instance details Defined in Json Methods showsPrec :: Int -> SyntaxException -> ShowS # show :: SyntaxException -> String # showList :: [SyntaxException] -> ShowS #
Eq SyntaxException Source #
Instance details Defined in Json Methods (==) :: SyntaxException -> SyntaxException -> Bool # (/=) :: SyntaxException -> SyntaxException -> Bool #

Classes

class ToValue a where Source #

Typeclass for types that can be encoded as JSON.

Methods

toValue :: a -> Value Source #

Instances

Instances details

ToValue Int16 Source #
Instance details Defined in Json Methods toValue :: Int16 -> Value Source #
ToValue Int32 Source #
Instance details Defined in Json Methods toValue :: Int32 -> Value Source #
ToValue Int64 Source #
Instance details Defined in Json Methods toValue :: Int64 -> Value Source #
ToValue Int8 Source #
Instance details Defined in Json Methods toValue :: Int8 -> Value Source #
ToValue Word16 Source #
Instance details Defined in Json Methods toValue :: Word16 -> Value Source #
ToValue Word32 Source #
Instance details Defined in Json Methods toValue :: Word32 -> Value Source #
ToValue Word64 Source #
Instance details Defined in Json Methods toValue :: Word64 -> Value Source #
ToValue Word8 Source #
Instance details Defined in Json Methods toValue :: Word8 -> Value Source #
ToValue Value Source #
Instance details Defined in Json Methods toValue :: Value -> Value Source #
ToValue Scientific Source #
Instance details Defined in Json Methods toValue :: Scientific -> Value Source #
ToValue Text Source #
Instance details Defined in Json Methods toValue :: Text -> Value Source #
ToValue ShortText Source #
Instance details Defined in Json Methods toValue :: ShortText -> Value Source #
ToValue () Source #	Encodes the unit value as JSON `null`.
Instance details Defined in Json Methods toValue :: () -> Value Source #
ToValue Bool Source #
Instance details Defined in Json Methods toValue :: Bool -> Value Source #
ToValue Int Source #
Instance details Defined in Json Methods toValue :: Int -> Value Source #
ToValue Word Source #
Instance details Defined in Json Methods toValue :: Word -> Value Source #
ToValue a => ToValue (Array a) Source #
Instance details Defined in Json Methods toValue :: Array a -> Value Source #
(Prim a, ToValue a) => ToValue (PrimArray a) Source #
Instance details Defined in Json Methods toValue :: PrimArray a -> Value Source #
ToValue a => ToValue (SmallArray a) Source #
Instance details Defined in Json Methods toValue :: SmallArray a -> Value Source #
ToValue a => ToValue [a] Source #
Instance details Defined in Json Methods toValue :: [a] -> Value Source #

Functions

decode :: Bytes -> Either SyntaxException Value Source #

Decode a JSON syntax tree from a byte sequence.

decodeNewlineDelimited :: Bytes -> Either SyntaxException (SmallArray Value) Source #

Decode newline-delimited JSON. Both the LF and the CRLF conventions are supported. The newline character (or character sequence) following the final object may be omitted. This also allows blanks lines consisting of only whitespace.

It's not strictly necessary for this to be a part of this library, but newline-delimited JSON is somewhat common in practice. It's nice to have this here instead of having to reimplement it in a bunch of different applications.

Note: To protect against malicious input, this reject byte sequences with more than 10 million newlines. If this is causing a problem for you, open an issue.

Other note: in the future, this function might be changed transparently to parallelize the decoding of large input (at least 1000 lines) with GHC sparks.

encode :: Value -> Builder Source #

Encode a JSON syntax tree.

toChunks :: Value -> Chunks Source #

toShortText :: Value -> ShortText Source #

toText :: Value -> Text Source #

toBytes :: Value -> Bytes Source #

toByteArray :: Value -> ByteArray Source #

Infix Synonyms

pattern (:->) :: ShortText -> Value -> Member Source #

Infix pattern synonym for Member.

Constants

emptyArray :: Value Source #

An array with no elements (i.e. [])

emptyObject :: Value Source #

An object with no members (i.e. {})

Value Construction

int :: Int -> Value Source #

int8 :: Int8 -> Value Source #

int16 :: Int16 -> Value Source #

int32 :: Int32 -> Value Source #

int64 :: Int64 -> Value Source #

word8 :: Word8 -> Value Source #

word16 :: Word16 -> Value Source #

word32 :: Word32 -> Value Source #

word64 :: Word64 -> Value Source #

bool :: Bool -> Value Source #

text :: Text -> Value Source #

shortText :: ShortText -> Value Source #

Array Construction

arrayFromList :: [Value] -> Value Source #

Construct a JSON array from a list of JSON values.

Unlike objectFromList, this is not currently equipped with a rewrite rule.

Object Construction

objectFromList :: [Member] -> Value Source #

Construct a JSON object from a list of members.

Note: When the argument is a list literal with 16 or fewer elements, a rewrite rule transforms this into the appropriate objectN function. When the argument is not a list literal, this function just calls smallArrayFromList on the members, which has poor performance.

object1 :: Member -> Value Source #

Construct a JSON object with one member.

object2 :: Member -> Member -> Value Source #

Construct a JSON object with two members.

object3 :: Member -> Member -> Member -> Value Source #

Construct a JSON object with three members.

object4 :: Member -> Member -> Member -> Member -> Value Source #

Construct a JSON object with four members.

object5 :: Member -> Member -> Member -> Member -> Member -> Value Source #

Construct a JSON object with five members.

object6 :: Member -> Member -> Member -> Member -> Member -> Member -> Value Source #

Construct a JSON object with six members.